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1 | Question | Correct response | Correctness | Medical Chat Output | |||
2 | A junior orthopaedic surgery resident is completing a carpal tunnel repair with the department chairman as the attending physician. During the case, the resident inadvertently cuts a flexor tendon. The tendon is repaired without complication. The attending tells the resident that the patient will do fine, and there is no need to report this minor complication that will not harm the patient, as he does not want to make the patient worry unnecessarily. He tells the resident to leave this complication out of the operative report. Which of the following is the correct next action for the resident to take? Options: (A): Disclose the error to the patient but leave it out of the operative report (B): Disclose the error to the patient and put it in the operative report (C): Tell the attending that he cannot fail to disclose this mistake (D): Report the physician to the ethics committee (E): Refuse to dictate the operative report | Tell the attending that he cannot fail to disclose this mistake | Correct | The correct answer is (C): Tell the attending that he cannot fail to disclose this mistake. Explanation: In this scenario, the attending physician is advising the resident to withhold information about a complication from the patient and exclude it from the operative report. However, it is important for the resident to prioritize patient safety and ethical responsibility. Surgeons have a duty to communicate complications that result from surgical procedures, even if they are considered minor or do not harm the patient. The resident should inform the attending physician that they cannot fail to disclose this mistake to the patient. Open and honest communication with patients is essential for maintaining trust and ensuring patient autonomy. By disclosing the error to the patient, the resident allows the patient to make informed decisions about their care and potential follow-up treatments. Additionally, including the complication in the operative report ensures accurate documentation of the procedure and any associated complications, which is important for future reference and potential legal purposes. Reporting the physician to the ethics committee or refusing to dictate the operative report may not be necessary or appropriate actions in this situation. The resident should first address the issue with the attending physician and advocate for proper disclosure and documentation. | |||
3 | A 67-year-old man with transitional cell carcinoma of the bladder comes to the physician because of a 2-day history of ringing sensation in his ear. He received this first course of neoadjuvant chemotherapy 1 week ago. Pure tone audiometry shows a sensorineural hearing loss of 45 dB. The expected beneficial effect of the drug that caused this patient's symptoms is most likely due to which of the following actions? Options: (A): Inhibition of thymidine synthesis (B): Inhibition of proteasome (C): Hyperstabilization of microtubules (D): Generation of free radicals (E): Cross-linking of DNA | Cross-linking of DNA | Correct | The correct choice is (E) Cross-linking of DNA. Explanation: The patient's symptoms of ringing sensation in the ear and sensorineural hearing loss are consistent with ototoxicity, which is a known side effect of certain chemotherapy drugs. The most common chemotherapy drug associated with ototoxicity is cisplatin, which is commonly used in the treatment of transitional cell carcinoma of the bladder. Cisplatin exerts its antitumor effects by cross-linking DNA, which leads to DNA damage and inhibition of DNA replication and transcription. However, this cross-linking of DNA can also affect normal cells, including the cells of the inner ear, leading to ototoxicity. The symptoms of ototoxicity, such as ringing sensation in the ear and sensorineural hearing loss, are a result of damage to the hair cells in the cochlea, which are responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. The cross-linking of DNA by cisplatin can lead to damage and death of these hair cells, resulting in hearing loss. Therefore, the expected beneficial effect of the drug that caused this patient's symptoms is most likely due to its ability to cross-link DNA. | |||
4 | Two weeks after undergoing an emergency cardiac catherization with stenting for unstable angina pectoris, a 61-year-old man has decreased urinary output and malaise. He has type 2 diabetes mellitus and osteoarthritis of the hips. Prior to admission, his medications were insulin and naproxen. He was also started on aspirin, clopidogrel, and metoprolol after the coronary intervention. His temperature is 38°C (100.4°F), pulse is 93/min, and blood pressure is 125/85 mm Hg. Examination shows mottled, reticulated purplish discoloration of the feet. Laboratory studies show: Hemoglobin count 14 g/dL Leukocyte count 16,400/mm3 Segmented neutrophils 56% Eosinophils 11% Lymphocytes 31% Monocytes 2% Platelet count 260,000/mm3 Erythrocyte sedimentation rate 68 mm/h Serum Urea nitrogen 25 mg/dL Creatinine 4.2 mg/dL Renal biopsy shows intravascular spindle-shaped vacuoles. Which of the following is the most likely cause of this patient's symptoms?" Options: (A): Renal papillary necrosis (B): Allergic interstitial nephritis (C): Cholesterol embolization (D): Eosinophilic granulomatosis with polyangiitis (E): Polyarteritis nodosa | Cholesterol embolization | Correct | The correct answer is (C) Cholesterol embolization. Explanation: The patient's symptoms, including decreased urinary output and malaise, along with the laboratory findings of elevated serum creatinine and intravascular spindle-shaped vacuoles on renal biopsy, are consistent with cholesterol embolization syndrome. Cholesterol embolization occurs when atherosclerotic plaques in large arteries rupture, releasing cholesterol crystals into the bloodstream. These crystals can then lodge in small blood vessels, including those in the kidneys, leading to tissue ischemia and organ dysfunction. The patient's history of undergoing cardiac catheterization with stenting is a risk factor for cholesterol embolization, as the procedure can disrupt atherosclerotic plaques. Additionally, the mottled, reticulated purplish discoloration of the feet, known as livedo reticularis, is a classic finding in cholesterol embolization syndrome. The other answer choices are less likely based on the clinical presentation and laboratory findings: - Renal papillary necrosis (A) typically presents with gross hematuria and flank pain, which are not described in this patient. - Allergic interstitial nephritis (B) typically presents with fever, rash, eosinophilia, and eosinophilic infiltrates on renal biopsy, which are not described in this patient. - Eosinophilic granulomatosis with polyangiitis (D), formerly known as Churg-Strauss syndrome, typically presents with asthma, eosinophilia, and systemic vasculitis, which are not described in this patient. - Polyarteritis nodosa (E) typically presents with systemic symptoms such as fever, weight loss, and myalgias, along with evidence of systemic vasculitis, which are not described in this patient. | |||
5 | A 39-year-old woman is brought to the emergency department because of fevers, chills, and left lower quadrant pain. Her temperature is 39.1°C (102.3°F), pulse is 126/min, respirations are 28/min, and blood pressure is 80/50 mm Hg. There is blood oozing around the site of a peripheral intravenous line. Pelvic examination shows mucopurulent discharge from the cervical os and left adnexal tenderness. Laboratory studies show: Platelet count 14,200/mm3 Fibrinogen 83 mg/mL (N = 200–430 mg/dL) D-dimer 965 ng/mL (N < 500 ng/mL) When phenol is applied to a sample of the patient's blood at 90°C, a phosphorylated N-acetylglucosamine dimer with 6 fatty acids attached to a polysaccharide side chain is identified. A blood culture is most likely to show which of the following?" Options: (A): Coagulase-positive, gram-positive cocci forming mauve-colored colonies on methicillin-containing agar (B): Encapsulated, gram-negative coccobacilli forming grey-colored colonies on charcoal blood agar (C): Spore-forming, gram-positive bacilli forming yellow colonies on casein agar (D): Lactose-fermenting, gram-negative rods forming pink colonies on MacConkey agar (E): Gamma-hemolytic, gram-positive cocci forming green colonies on vancomycin agar | Lactose-fermenting, gram-negative rods forming pink colonies on MacConkey agar | Correct | The correct answer is (D): Lactose-fermenting, gram-negative rods forming pink colonies on MacConkey agar. Explanation: The patient's presentation is consistent with pelvic inflammatory disease (PID), which is commonly caused by sexually transmitted infections (STIs) such as Neisseria gonorrhoeae and Chlamydia trachomatis. The presence of mucopurulent discharge from the cervical os and left adnexal tenderness supports this diagnosis. The laboratory findings are also suggestive of an infection. The low platelet count (14,200/mm3) and fibrinogen level (83 mg/mL) indicate disseminated intravascular coagulation (DIC), which can occur in severe infections. The elevated D-dimer level (965 ng/mL) further supports the presence of DIC. The phenol test is used to identify the presence of endotoxins, which are lipopolysaccharides found in the outer membrane of gram-negative bacteria. The identification of a phosphorylated N-acetylglucosamine dimer with 6 fatty acids attached to a polysaccharide side chain suggests the presence of endotoxins from gram-negative bacteria. The most likely gram-negative bacteria causing the infection in this patient is Escherichia coli, which is a common cause of PID. E. coli is a lactose-fermenting, gram-negative rod that can be identified by its ability to ferment lactose and form pink colonies on MacConkey agar. Therefore, the blood culture is most likely to show lactose-fermenting, gram-negative rods forming pink colonies on MacConkey agar. | |||
6 | A 35-year-old man comes to the physician because of itchy, watery eyes for the past week. He has also been sneezing multiple times a day during this period. He had a similar episode 1 year ago around springtime. He has iron deficiency anemia and ankylosing spondylitis. Current medications include ferrous sulfate, artificial tear drops, and indomethacin. He works as an elementary school teacher. His vital signs are within normal limits. Visual acuity is 20/20 without correction. Physical examination shows bilateral conjunctival injection with watery discharge. The pupils are 3 mm, equal, and reactive to light. Examination of the anterior chamber of the eye is unremarkable. Which of the following is the most appropriate treatment? Options: (A): Erythromycin ointment (B): Ketotifen eye drops (C): Warm compresses (D): Fluorometholone eye drops (E): Latanoprost eye drops | Ketotifen eye drops | Correct | The correct choice is (B) Ketotifen eye drops. Explanation: Based on the patient's symptoms and physical examination findings, the most likely diagnosis is allergic conjunctivitis. Allergic conjunctivitis is characterized by bilateral conjunctival injection, watery discharge, and itching. The patient's history of similar symptoms in the past, as well as his current symptoms of sneezing, further support this diagnosis. The most appropriate treatment for allergic conjunctivitis is anti-allergy eye drops. Ketotifen is an antihistamine that can be used as eye drops to relieve the symptoms of allergic conjunctivitis. It is effective in reducing itching, redness, and watery discharge. Ketotifen eye drops can be bought without a prescription and are a suitable first-line treatment for mild cases of allergic conjunctivitis. Erythromycin ointment (choice A) is an antibiotic and is not indicated for the treatment of allergic conjunctivitis. It would not address the underlying allergic inflammation. Warm compresses (choice C) can provide symptomatic relief for some types of conjunctivitis, such as viral or bacterial conjunctivitis, but they are not the most appropriate treatment for allergic conjunctivitis. Fluorometholone eye drops (choice D) and latanoprost eye drops (choice E) are not indicated for the treatment of allergic conjunctivitis. Fluorometholone is a corticosteroid eye drop that has more potent anti-inflammatory effects and is typically reserved for more severe cases or when other treatments have failed. Latanoprost is a prostaglandin analog used to treat glaucoma and is not indicated for allergic conjunctivitis. | |||
7 | A 39-year-old man presents to the emergency department because of progressively worsening chest pain and nausea that started at a local bar 30 minutes prior. The pain radiates to the epigastric area. He has a 5-year history of untreated hypertension. He has smoked 1 pack of cigarettes daily for the past 5 years and started abusing cocaine 2 weeks before his emergency room visit. The patient is diaphoretic and in marked distress. What should be the first step in management? Options: (A): Diltiazem (B): Labetalol (C): Nitroglycerin (D): Propranolol (E): Reassurance and continuous monitoring | Reassurance and continuous monitoring | Correct | The correct answer is (E) Reassurance and continuous monitoring. Explanation: Given the patient's symptoms of chest pain radiating to the epigastric area, along with the risk factors of untreated hypertension, smoking, and recent cocaine abuse, the most likely diagnosis is acute coronary syndrome (ACS). In this scenario, the first step in management should be to provide reassurance to the patient and initiate continuous monitoring. Reassurance is important to help alleviate the patient's distress and anxiety. Continuous monitoring allows for the assessment of vital signs, including heart rate, blood pressure, and oxygen saturation, which can provide important information about the patient's condition and guide further management. Administering medications such as Diltiazem, Labetalol, Nitroglycerin, or Propranolol without a proper evaluation and diagnosis can be potentially harmful and may delay appropriate treatment. Therefore, the initial focus should be on reassurance and continuous monitoring while further evaluation and diagnostic tests, such as an electrocardiogram (ECG) and cardiac enzymes, are performed to confirm the diagnosis of ACS and guide subsequent management. | |||
8 | A 68-year-old male comes to the physician for evaluation of right flank pain. He has a history of diabetes and peripheral artery disease. His blood pressure is 160/90 mm Hg. Physical examination shows abdominal tenderness and right flank tenderness. An ultrasound shows dilation of the right ureter and renal pelvis. Which of the following is the most likely underlying cause of this patient's condition? Options: (A): Renal artery stenosis (B): Benign prostatic hyperplasia (C): Diabetic nephropathy (D): Common iliac artery aneurysm (E): Urethral stricture | Common iliac artery aneurysm | Correct | The correct choice is (D) Common iliac artery aneurysm. Explanation: The patient's history of diabetes and peripheral artery disease, along with the physical examination findings of abdominal tenderness and right flank tenderness, suggest a vascular cause for his symptoms. The ultrasound findings of dilation of the right ureter and renal pelvis further support this suspicion. Common iliac artery aneurysm is a likely underlying cause in this patient, as it can lead to compression or obstruction of the ureter and renal pelvis, resulting in flank pain and dilation of the urinary tract. Renal artery stenosis, benign prostatic hyperplasia, diabetic nephropathy, and urethral stricture are less likely to cause these specific findings. | |||
9 | A 65-year-old man is brought to the emergency department 30 minutes after the onset of acute chest pain. He has hypertension and asthma. Current medications include atorvastatin, lisinopril, and an albuterol inhaler. He appears pale and diaphoretic. His pulse is 114/min and blood pressure is 130/88 mm Hg. An ECG shows ST-segment depressions in leads II, III, and aVF. Laboratory studies show an increased serum troponin T concentration. The patient is treated for acute coronary syndrome and undergoes percutaneous transluminal coronary angioplasty. At the time of discharge, echocardiography shows a left ventricular ejection fraction of 58%. In addition to aspirin, which of the following drugs should be added to this patient's medication regimen? Options: (A): Nifedipine (B): Enoxaparin (C): Clopidogrel (D): Spironolactone (E): Propranolol " | Clopidogrel | Correct | The correct choice is (C) Clopidogrel. Explanation: Clopidogrel is a platelet inhibitor that is commonly used in the management of acute coronary syndrome. It works by inhibiting the ADP receptor on platelets, preventing platelet aggregation and reducing the risk of thrombotic events. In this patient with acute coronary syndrome, adding clopidogrel to his medication regimen will further reduce the risk of future cardiovascular events. Nifedipine (A) is a calcium channel blocker that is primarily used for the treatment of hypertension and angina. While it may be beneficial in certain cases, it is not the most appropriate choice for this patient with acute coronary syndrome. Enoxaparin (B) is a low molecular weight heparin that is commonly used for anticoagulation in patients with acute coronary syndrome. While it may be beneficial in certain cases, it is not the most appropriate choice for this patient with acute coronary syndrome. Spironolactone (D) is a potassium-sparing diuretic that is primarily used for the treatment of heart failure. While it may be beneficial in certain cases, it is not the most appropriate choice for this patient with acute coronary syndrome. Propranolol (E) is a beta-blocker that is commonly used for the treatment of hypertension and angina. While it may be beneficial in certain cases, it is not the most appropriate choice for this patient with acute coronary syndrome. | |||
10 | A 37-year-old-woman presents to her primary care physician requesting a new form of birth control. She has been utilizing oral contraceptive pills (OCPs) for the past 8 years, but asks to switch to an intrauterine device (IUD). Her vital signs are: blood pressure 118/78 mm Hg, pulse 73/min and respiratory rate 16/min. She is afebrile. Physical examination is within normal limits. Which of the following past medical history statements would make copper IUD placement contraindicated in this patient? Options: (A): A history of stroke or venous thromboembolism (B): Current tobacco use (C): Active or recurrent pelvic inflammatory disease (PID) (D): Past medical history of breast cancer (E): Known liver neoplasm | Active or recurrent pelvic inflammatory disease (PID) | Correct | The correct choice is (C) Active or recurrent pelvic inflammatory disease (PID). Explanation: Active or recurrent pelvic inflammatory disease (PID) is a contraindication for copper IUD placement. PID is an infection of the female reproductive organs, including the uterus, fallopian tubes, and ovaries. It is usually caused by sexually transmitted infections, such as chlamydia or gonorrhea. The presence of active or recurrent PID increases the risk of complications with IUD placement, such as worsening infection or spreading of the infection to other parts of the reproductive system. Therefore, it is not recommended to place a copper IUD in a patient with active or recurrent PID. | |||
11 | A 23-year-old woman comes to the physician because she is embarrassed about the appearance of her nails. She has no history of serious illness and takes no medications. She appears well. A photograph of the nails is shown. Which of the following additional findings is most likely in this patient? Options: (A): Silvery plaques on extensor surfaces (B): Flesh-colored papules in the lumbosacral region (C): Erosions of the dental enamel (D): Pallor of the conjunctival mucosa (E): Holosystolic murmur at the left lower sternal border | Silvery plaques on extensor surfaces | Correct | The correct answer is (A) Silvery plaques on extensor surfaces. Explanation: The photograph of the nails shows pitting and onycholysis, which are characteristic findings of psoriasis. Psoriasis is a chronic autoimmune condition that primarily affects the skin and nails. Silvery plaques on extensor surfaces, such as the elbows and knees, are classic findings in psoriasis. Therefore, the most likely additional finding in this patient would be silvery plaques on extensor surfaces. Psoriasis can also affect other areas of the body, including the scalp, trunk, and nails. It is important to note that psoriasis can vary in severity and may be associated with joint pain and swelling (psoriatic arthritis) in some cases. However, the question does not provide any information about joint symptoms, so the most likely finding to be associated with psoriasis in this patient is silvery plaques on extensor surfaces. | |||
12 | A 24-year-old G2P1 woman at 39 weeks’ gestation presents to the emergency department complaining of painful contractions occurring every 10 minutes for the past 2 hours, consistent with latent labor. She says she has not experienced vaginal discharge, bleeding, or fluid leakage, and is currently taking no medications. On physical examination, her blood pressure is 110/70 mm Hg, heart rate is 86/min, and temperature is 37.6°C (99.7°F). She has had little prenatal care and uses condoms inconsistently. Her sexually transmitted infections status is unknown. As part of the patient’s workup, she undergoes a series of rapid screening tests that result in the administration of zidovudine during delivery. The infant is also given zidovudine to reduce the risk of transmission. A confirmatory test is then performed in the mother to confirm the diagnosis of HIV. Which of the following is most true about the confirmatory test? Options: (A): It determines the genotype of the virus (B): It is a Southwestern blot, identifying the presence of DNA-binding proteins (C): It is a Northern blot, identifying the presence of RNA (D): It is a Northern blot, identifying the presence of DNA (E): It is an HIV-1/HIV2 antibody differentiation immunoassay | It is an HIV-1/HIV2 antibody differentiation immunoassay | Correct | The correct choice is (E) It is an HIV-1/HIV2 antibody differentiation immunoassay. Explanation: In this scenario, the patient undergoes rapid screening tests that result in the administration of zidovudine during delivery, indicating a positive result for HIV. A confirmatory test is then performed to confirm the diagnosis of HIV. The most appropriate confirmatory test in this case is an HIV-1/HIV2 antibody differentiation immunoassay. The confirmatory test is used to differentiate between HIV-1 and HIV-2 antibodies. HIV-1 is the most common type of HIV infection worldwide, while HIV-2 is less common and primarily found in West Africa. The confirmatory test helps determine the specific type of HIV infection the patient has. Options A, B, C, and D are incorrect because they do not accurately describe the purpose or method of the confirmatory test for HIV. The confirmatory test does not determine the genotype of the virus (Option A), use a Southwestern blot to identify DNA-binding proteins (Option B), use a Northern blot to identify RNA (Option C), or use a Northern blot to identify DNA (Option D). | |||
13 | A 72-year-old man comes to the physician because of a 2-month history of fatigue and worsening abdominal pain. During this period, he also has excessive night sweats and shortness of breath on exertion. Over the past 3 months, he has had a 5.6-kg (12-lb) weight loss. He had a myocardial infarction 3 years ago. He has hypertension, diabetes mellitus, and chronic bronchitis. His medications include insulin, aspirin, lisinopril, and an albuterol inhaler. He has smoked half a pack of cigarettes for the past 45 years. Vital signs are within normal limits. The spleen is palpated 6 cm below the left costal margin. Laboratory studies show: Hemoglobin 6.4 g/dL Mean corpuscular volume 85 μm3 Leukocyte count 5,200/mm3 Platelet count 96,000/mm3 A blood smear is shown. Bone marrow aspiration shows extensive fibrosis and a few scattered plasma cells. A JAK 2 assay is positive. Which of the following is the most appropriate next step in management?" Options: (A): Cladribine (B): Prednisone (C): Imatinib (D): Ruxolitinib (E): Stem cell transplantation | Ruxolitinib | Correct | The correct choice is (D) Ruxolitinib. Explanation: Based on the patient's clinical presentation and laboratory findings, the most likely diagnosis is myelofibrosis. Myelofibrosis is a myeloproliferative neoplasm characterized by bone marrow fibrosis, resulting in cytopenias and extramedullary hematopoiesis. The JAK2 mutation is commonly associated with myelofibrosis. Ruxolitinib is a JAK1/JAK2 inhibitor that has been shown to improve symptoms and reduce spleen size in patients with myelofibrosis. It is the most appropriate next step in management for this patient. Cladribine (A) is a purine analog that is used in the treatment of hairy cell leukemia, not myelofibrosis. Prednisone (B) is a corticosteroid that may be used in the treatment of autoimmune disorders and certain hematologic malignancies, but it is not the first-line treatment for myelofibrosis. Imatinib (C) is a tyrosine kinase inhibitor that is used in the treatment of chronic myeloid leukemia (CML), not myelofibrosis. Stem cell transplantation (E) may be considered in younger patients with myelofibrosis who have a suitable donor, but it is not the first-line treatment option for this patient. | |||
14 | A 20-year-old man comes to the physician because of worsening gait unsteadiness and bilateral hearing loss for 1 month. He has had intermittent tingling sensations on both cheeks over this time period. He has no history of serious medical illness and takes no medications. Audiometry shows bilateral sensorineural hearing loss. Genetic evaluation shows a mutation of a tumor suppressor gene on chromosome 22 that encodes merlin. This patient is at increased risk for which of the following conditions? Options: (A): Renal cell carcinoma (B): Meningioma (C): Astrocytoma (D): Vascular malformations (E): Telangiectasias | Meningioma | Correct | The correct answer is (B) Meningioma. Explanation: The patient's symptoms of gait unsteadiness, bilateral hearing loss, and tingling sensations on both cheeks, along with the genetic evaluation showing a mutation of a tumor suppressor gene on chromosome 22 that encodes merlin, are consistent with a diagnosis of neurofibromatosis type 2 (NF2). NF2 is a genetic disorder characterized by the development of multiple tumors in the nervous system, particularly in the central nervous system. Meningiomas are one of the most common tumors associated with NF2, occurring in up to 70% of cases. Therefore, this patient is at increased risk for developing meningiomas. Renal cell carcinoma, astrocytoma, vascular malformations, and telangiectasias are not typically associated with NF2. | |||
15 | A 47-year-old executive schedules an appointment his physician for a routine medical check-up. He currently has no complaints and claims to be “as fit as a fiddle.” The physical examination findings are unremarkable, except for a mid-systolic murmur heard in the 2nd left intercostal space that radiates to the carotids on auscultation. The physician instructs the patient to stand from a supine position with the stethoscope still placed on his chest. Which of the following changes would occur with this maneuver? Options: (A): An increase in right atrial pressure (B): An increase in left ventricular end-diastolic pressure (C): An increase in pulmonary capillary wedge pressure (D): A reduction in the slope of the pacemaker potential (E): A reduction in diastolic filling time | A reduction in diastolic filling time | Correct | The correct choice is (E) A reduction in diastolic filling time. Explanation: When a person stands up from a supine position, there is a shift of blood volume from the thoracic cavity to the lower extremities due to the effect of gravity. This results in a decrease in venous return to the heart. As a result, there is a reduction in diastolic filling time, which is the time during which the ventricles fill with blood. This reduction in diastolic filling time leads to a decrease in left ventricular end-diastolic volume and pressure. This decrease in left ventricular end-diastolic pressure is reflected in a decrease in the intensity of the mid-systolic murmur heard in the 2nd left intercostal space that radiates to the carotids on auscultation. Therefore, the correct answer is (E) A reduction in diastolic filling time. | |||
16 | A microbiologist is studying the emergence of a virulent strain of the virus. After a detailed study of the virus and its life cycle, he proposes a theory: Initially, a host cell is co-infected with 2 viruses from the same virus family. Within the host cell, concomitant production of various genome segments from both viruses occurs. Ultimately, the different genome segments from the viruses are packaged into a unique and novel virus particle. The newly formed virus particle is both stable and viable and is a new strain from the virus family that caused the outbreak of infection. Which of the following viruses is capable of undergoing the above-mentioned process? Options: (A): Cytomegalovirus (B): Epstein-Barr virus (C): Human immunodeficiency virus (D): Rotavirus (E): Vaccinia virus | Rotavirus | Correct | The correct choice is (D) Rotavirus. Explanation: According to the given information, the process described involves the co-infection of a host cell with two viruses from the same virus family, followed by the production of various genome segments from both viruses within the host cell. These different genome segments are then packaged into a unique and novel virus particle, which is stable and viable and represents a new strain from the virus family. Among the given options, rotavirus is the most likely virus to undergo this process. Rotavirus is a double-stranded RNA virus that belongs to the Reoviridae family. It is known to have a segmented genome, with 11 segments of RNA. This segmented genome allows for the exchange and recombination of genetic material during co-infection, leading to the production of novel virus particles with unique combinations of genome segments. In contrast, the other options (A) Cytomegalovirus, (B) Epstein-Barr virus, (C) Human immunodeficiency virus, and (E) Vaccinia virus do not have segmented genomes and are less likely to undergo the described process of co-infection and recombination of genome segments. Therefore, the most likely virus capable of undergoing the above-mentioned process is (D) Rotavirus. | |||
17 | A 59-year-old overweight woman presents to the urgent care clinic with the complaint of severe abdominal pain for the past 2 hours. She also complains of a dull pain in her back with nausea and vomiting several times. Her pain has no relation with food. Her past medical history is significant for recurrent abdominal pain due to cholelithiasis. Her father died at the age of 60 with some form of abdominal cancer. Her temperature is 37°C (98.6°F), respirations are 15/min, pulse is 67/min, and blood pressure is 122/98 mm Hg. Physical exam is unremarkable. However, a CT scan of the abdomen shows a calcified mass near her gallbladder. Which of the following diagnoses should be excluded first in this patient? Options: (A): Acute cholecystitis (B): Gallbladder cancer (C): Choledocholithiasis (D): Pancreatitis (E): Duodenal peptic ulcer | Gallbladder cancer | Correct | The correct answer is (B) Gallbladder cancer. Explanation: In this patient, the presence of a calcified mass near the gallbladder on CT scan raises concern for gallbladder cancer. The patient's symptoms of severe abdominal pain, dull back pain, nausea, and vomiting are concerning for a serious underlying condition. The fact that the pain is not related to food and the patient's history of recurrent abdominal pain due to cholelithiasis further raises suspicion for gallbladder cancer. Additionally, the patient's family history of abdominal cancer, specifically her father's death at the age of 60, is also concerning for a hereditary component. Therefore, gallbladder cancer should be excluded first in this patient. Acute cholecystitis, choledocholithiasis, pancreatitis, and duodenal peptic ulcer are all possible differential diagnoses, but gallbladder cancer should be the primary concern given the clinical presentation and imaging findings. | |||
18 | A 7-year-old boy is brought to his pediatrician’s office for a follow-up visit. He was diagnosed with asthma when he was 3 years old and has since been on treatment for the condition. He is currently on a β-agonist inhaler because of exacerbation of his symptoms. He has observed that his symptoms are more prominent in springtime, especially when the new flowers are blooming. His mother has a backyard garden and whenever he goes out to play there, he experiences chest tightness with associated shortness of breath. He has been advised to take more precaution during this seasonal change and to stay away from pollen. He is also being considered for an experimental therapy, which attenuates the activity of certain mediators which cause his asthmatic attack. The targeted mediator favors the class switching of antibodies. A reduction in this mechanism will eventually reduce the exaggerated response observed during his asthmatic attacks, even when exposed to an allergen. Which of the following mediators is described in this experimental study? Options: (A): IL-5 (B): IL-2 (C): IL-10 (D): IL-13 (E): IL-4 | IL-4 | Correct | The correct choice is (E) IL-4. Explanation: In this experimental study, the targeted mediator is described as favoring the class switching of antibodies. This indicates that the mediator is involved in the production of IgE antibodies, which play a key role in allergic reactions, including asthma. IL-4 is known to induce B-cell proliferation and stimulate these cells to produce IgE. Therefore, reducing the activity of IL-4 will decrease the production of IgE antibodies, leading to a reduction in the exaggerated response observed during asthmatic attacks, even when exposed to an allergen. IL-5, IL-2, IL-10, and IL-13 are not directly involved in the class switching of antibodies and do not have the same impact on IgE production as IL-4. | |||
19 | A 3-month-old boy is brought the emergency department by his parents after an episode of cyanosis and muscle hypotonia that resolved after 2 minutes. Diagnostic evaluation fails to discover an exact etiology of the boy's symptoms and the episode is classified as a brief resolved unexplained event (BRUE). The risk profile for BRUE in infants remains largely unknown. The pediatrician who saw the boy in the emergency department is trying to identify risk factors for BRUE. She is aware of several confounders, including age, socioeconomic background, and family history of medical illness. She recruits 75 infants under 1 year of age with BRUE and 75 infants without BRUE of the same age, socioeconomic background, and family history of medical illness. She then compares the two groups with regard to history of feeding problems and history of recent upper respiratory infection. Which of the following methods was conducted to control confounding bias in the study? Options: (A): Stratified analysis (B): Blinding (C): Restriction (D): Randomization (E): Matching | Matching | Correct | The correct choice is (E) Matching. Explanation: Matching is a method used to control confounding bias in a study. In this case, the pediatrician recruited 75 infants with BRUE and 75 infants without BRUE, and matched them based on age, socioeconomic background, and family history of medical illness. By matching the two groups, the pediatrician ensured that these potential confounders were evenly distributed between the groups, reducing the likelihood of bias. This allows for a more accurate comparison of the two groups with regard to history of feeding problems and history of recent upper respiratory infection. Matching is an effective method to control for confounding variables and improve the internal validity of a study. | |||
20 | A 29-year-old man presents to the emergency department due to central chest pain over the past 3 days which is constant and unrelated to exertion. The pain is sharp, severe, increases when lying down, and improves with leaning forward. The pain also radiates to his shoulders and neck. The patient has no past medical history. He has smoked 10 cigarettes per day for the past 7 years and occasionally drinks alcohol. He presents with vital signs: blood pressure 110/70 mm Hg, regular radial pulse of 95/min, and temperature 37.3°C (99.1°F). On physical exam, a scratching sound of to-and-from character is audible over the left sternal border at end-expiration with the patient leaning forward. His chest X-ray is normal and ECG is shown in the picture. Which of the following is the optimal therapy for this patient? Options: (A): Indomethacin +/- omeprazole (B): Ibuprofen + colchicine +/- omeprazole (C): Prednisone + colchicine (D): Pericardiocentesis (E): Pericardiectomy | Ibuprofen + colchicine +/- omeprazole | Correct | The correct choice is (B) Ibuprofen + colchicine +/- omeprazole. Explanation: Based on the patient's presentation and physical exam findings, the most likely diagnosis is acute pericarditis. The sharp, severe chest pain that increases when lying down and improves with leaning forward is a classic symptom of pericarditis. The radiation of pain to the shoulders and neck is also consistent with pericarditis. The scratching sound of to-and-fro character heard over the left sternal border at end-expiration with the patient leaning forward is known as a pericardial friction rub, which is another characteristic finding of pericarditis. The ECG shown in the picture may show diffuse ST-segment elevations and PR-segment depressions, which are also typical findings in acute pericarditis. The optimal therapy for acute pericarditis is nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, along with colchicine. NSAIDs help reduce inflammation and relieve pain, while colchicine helps prevent recurrences of pericarditis. Omeprazole, a proton pump inhibitor, may be added to the treatment regimen to prevent gastrointestinal side effects from NSAIDs. Indomethacin (option A) is an NSAID that can be used for pericarditis, but ibuprofen is a more commonly used and preferred option. Prednisone (option C) is a corticosteroid that may be used in refractory cases of pericarditis, but it is not the first-line treatment. Pericardiocentesis (option D) is a procedure used to drain fluid from the pericardial sac in cases of cardiac tamponade or purulent pericarditis. It is not indicated in the management of acute pericarditis. Pericardiectomy (option E) is a surgical procedure to remove the pericardium and is reserved for cases of chronic or recurrent pericarditis that do not respond to medical therapy. It is not the initial treatment for acute pericarditis. | |||
21 | A 46-year-old man is brought to the emergency department for evaluation of altered mental status. He was found on the floor in front of his apartment. He is somnolent but responsive when aroused. His pulse is 64/min, respiratory rate is 15/min, and blood pressure is 120/75 mm Hg. On physical examination, an alcoholic smell and slurred speech are noted. Neurological exam shows diminished deep tendon reflexes bilaterally and an ataxic gait. His pupils are normal. Blood alcohol concentration is 0.04%. An ECG shows no abnormalities. Which of the following is the most likely cause of this patient's symptoms? Options: (A): Hypoglycemia (B): Cerebral ischemia (C): Ethanol intoxication (D): Cannabis intoxication (E): Benzodiazepine intoxication " | Benzodiazepine intoxication " | Correct | The correct choice is (E): Benzodiazepine intoxication. Explanation: Based on the patient's presentation and the information provided, the most likely cause of his symptoms is benzodiazepine intoxication. The patient has an altered mental status, somnolence, slurred speech, and an ataxic gait, which are all consistent with the central nervous system depressant effects of benzodiazepines. The presence of an alcoholic smell suggests that the patient may have consumed alcohol, but the blood alcohol concentration of 0.04% is relatively low and unlikely to be the sole cause of his symptoms. Additionally, the normal pupils and absence of abnormalities on the ECG make other options less likely. Hypoglycemia can cause altered mental status, but the patient's blood glucose level is not provided and there are no other signs or symptoms to suggest hypoglycemia. Cerebral ischemia would typically present with focal neurological deficits, such as weakness or sensory loss, which are not described in this patient. Cannabis intoxication can cause altered mental status, but it is less likely given the patient's presentation and the absence of other typical signs and symptoms. Therefore, the most likely cause of this patient's symptoms is benzodiazepine intoxication. | |||
22 | A 77-year-old woman presents to the emergency room with the complaints of fever, malaise, and night sweats. She recently observed an enlargement of her axillary lymph nodes, which she examines on a weekly basis. She has a remote history of breast cancer in her 60s that was treated with radiation and chemotherapy. She also reports a history of extensive travel to Africa and a 30-pack-year history of smoking. On physical exam, several axillary lymph nodes are palpable with a large non-tender palpable mass in her right axilla measuring 10 x 8 cm. Fine-needle aspiration demonstrates what the pathologist describes as "a centroblastic and immunoblastic cell presence, suspicious for non-Hodgkin’s lymphoma (NHL)–diffuse large B cell variant". Which of the following risk factors is responsible for this patient’s condition? Options: (A): Travel to Africa (B): Axillary lymph node involvement (C): Previous radiation therapy (D): Female gender (E): Previous breast cancer | Previous radiation therapy | Correct | The correct answer is (C): Previous radiation therapy. Explanation: The patient's history of previous radiation therapy for breast cancer is the most significant risk factor for her current condition of non-Hodgkin's lymphoma (NHL). Radiation therapy is a known risk factor for the development of secondary malignancies, including lymphomas. The fact that the patient has a large mass in her axilla, along with the presence of centroblastic and immunoblastic cells on fine-needle aspiration, is consistent with NHL. The other options, such as travel to Africa, axillary lymph node involvement, female gender, and previous breast cancer, are not directly associated with the development of NHL in this case. | |||
23 | A 3-month-old infant is brought to her pediatrician because she coughs and seems to have difficulty breathing while feeding. In addition, she seems to have less energy compared to other babies and appears listless throughout the day. She was born by cesarean section to a G1P1 woman with no prior medical history and had a normal APGAR score at birth. Her parents say that she has never been observed to turn blue. Physical exam reveals a high-pitched holosystolic murmur that is best heard at the lower left sternal border. The most likely cause of this patient's symptoms is associated with which of the following abnormalities? Options: (A): 22q11 deletion (B): Deletion of genes on chromosome 7 (C): Lithium exposure in utero (D): Maternal alcohol consumption (E): Retinoic acid exposure in utero | 22q11 deletion | Correct | The correct choice is (A) 22q11 deletion. Explanation: The symptoms described in the scenario, including coughing, difficulty breathing while feeding, decreased energy, and a high-pitched holosystolic murmur, are consistent with a congenital heart defect. The most likely cause of these symptoms in this patient is a 22q11 deletion, also known as DiGeorge syndrome or velocardiofacial syndrome. DiGeorge syndrome is a genetic disorder caused by a deletion of a small piece of chromosome 22. This deletion can result in a variety of abnormalities, including congenital heart defects, immune system dysfunction, and facial abnormalities. The high-pitched holosystolic murmur heard on physical exam is likely due to a ventricular septal defect (VSD), which is a common cardiac anomaly associated with 22q11 deletion. The other options listed (B, C, D, and E) are not associated with the characteristic symptoms and findings described in the scenario. Deletion of genes on chromosome 7, lithium exposure in utero, maternal alcohol consumption, and retinoic acid exposure in utero are not typically associated with congenital heart defects or the specific clinical presentation described in this patient. | |||
24 | A 30-year-old African American woman comes to the physician for the evaluation of a dry cough and chest discomfort for the past 3 days. During this period, the patient has had headaches, muscle aches, joint pain, fever, and chills. Ten days ago, she was hiking with her family in Mississippi. The patient has asthma that is treated with an albuterol inhaler. Her mother has a lung disease treated with methotrexate. The patient has smoked one pack of cigarettes daily for the past 10 years. Her temperature is 38°C (100.4°F). Physical examination shows slight wheezes throughout both lung fields. Laboratory studies and urinalysis are positive for polysaccharide antigen. Bronchoalveolar lavage using silver/PAS-staining shows macrophages filled with a dimorphic fungus with septate hyphae. Which of the following is the most likely cause of this patient's symptoms? Options: (A): Legionella pneumophila infection (B): Aspergillus fumigatus infection (C): Pneumocystis pneumonia (D): Histoplasma capsulatum infection (E): Blastomyces dermatitidis infection | Histoplasma capsulatum infection | Correct | The correct choice is (D) Histoplasma capsulatum infection. Explanation: The patient's symptoms, including dry cough, chest discomfort, headaches, muscle aches, joint pain, fever, and chills, along with the history of hiking in Mississippi, are suggestive of a fungal infection. The presence of slight wheezes throughout both lung fields on physical examination further supports a respiratory infection. The positive polysaccharide antigen in the laboratory studies and urinalysis indicates the presence of a fungal infection. Bronchoalveolar lavage using silver/PAS-staining shows macrophages filled with a dimorphic fungus with septate hyphae. This finding is characteristic of Histoplasma capsulatum infection. Histoplasma capsulatum is a dimorphic fungus that exists as a mold in the environment and as a yeast in the host. It is commonly found in soil contaminated with bird or bat droppings, and inhalation of the spores can lead to infection. The patient's asthma and smoking history may increase her risk of developing a fungal infection. Asthma is a chronic inflammatory condition that can weaken the immune system, making individuals more susceptible to infections. Smoking also impairs the immune system and damages the respiratory epithelium, making it easier for pathogens to enter the lungs. Therefore, based on the patient's symptoms, exposure history, laboratory findings, and bronchoalveolar lavage results, the most likely cause of her symptoms is a Histoplasma capsulatum infection. | |||
25 | A 62-year-old patient has been hospitalized for a week due to a stroke. One week into the hospitalization, he develops a fever and purulent cough. His vitals include: heart rate 88/min, respiratory rate 20/min, temperature 38.4°C (101.1°F), and blood pressure 110/85 mm Hg. On physical examination, he has basal crackles on the right side of the chest. Chest radiography shows a new consolidation on the same side. Complete blood count is as follows: Hemoglobin 16 mg/dL Hematocrit 50% Leukocyte count 8,900/mm3 Neutrophils 72% Bands 4% Eosinophils 2% Basophils 0% Lymphocytes 17% Monocytes 5% Platelet count 280,000/mm3 What is the most likely causal microorganism? Options: (A): Pseudomona aeruginosa (B): Streptococcus pneumoniae (C): Mycobacterium tuberculosis (D): Haemophilus influenzae (E): Staphylococcus aureus | Staphylococcus aureus | Correct | The correct answer is (E): Staphylococcus aureus. Explanation: Based on the clinical presentation and laboratory findings, the most likely causal microorganism in this case is Staphylococcus aureus. The patient has developed a fever and purulent cough, which are suggestive of a respiratory infection. The presence of basal crackles on the right side of the chest and a new consolidation on chest radiography further support the diagnosis of a lower respiratory tract infection. The complete blood count shows an elevated leukocyte count with a predominance of neutrophils (72%) and bands (4%). This indicates an acute bacterial infection, as neutrophils are the primary cells involved in the body's defense against bacterial pathogens. The presence of bands, which are immature neutrophils, suggests an ongoing infection. Staphylococcus aureus is a common cause of community-acquired pneumonia and can also cause healthcare-associated pneumonia. It is known to cause lung infections with purulent sputum and can lead to lung abscesses or empyema. The patient's hospitalization for a week increases the likelihood of healthcare-associated pneumonia. While other microorganisms, such as Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa, can also cause pneumonia, the clinical presentation and laboratory findings in this case are more consistent with Staphylococcus aureus infection. Mycobacterium tuberculosis is unlikely in this case as the patient's symptoms and radiographic findings are suggestive of an acute infection rather than a chronic tuberculosis infection. | |||
26 | A 6-year-old boy is brought to the emergency department by his mother for worsening wheezing and shortness of breath over the past day. He has not had a fever, cough, vomiting, or diarrhea. He has asthma and eczema. He uses a glucocorticoid inhaler and an albuterol inhaler but has missed his medications for the past week while on vacation. He appears uncomfortable. His temperature is 36°C (96.8°F), pulse is 120/min, respirations are 40/min, and blood pressure is 100/80. Expiratory and inspiratory wheezing is heard throughout both lung fields. There are moderate intercostal and subcostal retractions and a decreased inspiratory to expiratory ratio. Nebulized albuterol and ipratropium treatments and intravenous methylprednisolone are given in the emergency department for a presumed asthma exacerbation. One hour later, the child is limp and lethargic. Magnesium sulfate is administered. His temperature is 36°C (96.8°F), pulse is 150/min, respirations are 22/min, and blood pressure is 100/70. No wheezing is heard on repeat pulmonary examination. Which of the following is the most appropriate next step in management? Options: (A): Intubate with mechanical ventilation (B): Perform needle thoracostomy at the 2nd intercostal space (C): Perform bronchoscopy (D): Provide helium and oxygen mixture (E): Provide additional dose of methylprednisolone | Intubate with mechanical ventilation | Correct | The correct choice is (A) Intubate with mechanical ventilation. Explanation: The patient in this scenario is experiencing a severe asthma exacerbation that has not responded to initial treatment with nebulized albuterol, ipratropium, and intravenous methylprednisolone. The child is now limp and lethargic, with a high heart rate and decreased respiratory rate. These signs indicate impending respiratory failure and the need for immediate intervention. Intubation with mechanical ventilation is the most appropriate next step in management for this patient. Intubation will secure the airway and allow for the delivery of positive pressure ventilation, which can help improve oxygenation and ventilation in patients with severe respiratory distress or failure. It also allows for the administration of medications directly into the lungs, such as continuous nebulized albuterol. Performing a needle thoracostomy at the 2nd intercostal space (B) is not indicated in this patient. Needle thoracostomy is performed to relieve tension pneumothorax, which is not suggested by the clinical presentation in this case. Performing bronchoscopy (C) is not indicated as the next step in management for this patient. Bronchoscopy is an invasive procedure that is typically reserved for cases where there is suspicion of a foreign body or other anatomical obstruction in the airway. Providing a helium and oxygen mixture (D) is not indicated in this patient. Helium-oxygen mixtures, also known as heliox, can be used in patients with severe airway obstruction to reduce airway resistance and improve gas flow. However, in this case, the patient's symptoms are not suggestive of severe airway obstruction. Providing an additional dose of methylprednisolone (E) is not the most appropriate next step in management for this patient. The patient has already received intravenous methylprednisolone, and the lack of response to this treatment suggests the need for more aggressive intervention, such as intubation and mechanical ventilation. | |||
27 | A 5-year-old female suffers from recurrent infections by Aspergillus species, Pseudomonas species, and Staphylococcus aureus. The patient's neutrophils are examined in the laboratory and they fail to react during the nitroblue tetrazolium test. Which of the following is most likely dysfunctional in this patient? Options: (A): Lymphocytes (B): Immunoglobulin class switching (C): Superoxide dismutase (D): Myeloperoxidase (E): Respiratory burst | Respiratory burst | Correct | The correct choice is (E) Respiratory burst. Explanation: The patient's neutrophils fail to react during the nitroblue tetrazolium (NBT) test, which is used to measure the respiratory burst activity of phagocytic cells. The respiratory burst is the process by which phagocytic cells, such as neutrophils, generate reactive oxygen species (ROS) to kill pathogens. In this case, the patient's neutrophils are unable to produce oxygen radicals during phagocytosis, indicating a dysfunction in the respiratory burst. The respiratory burst is an essential component of the innate immune response and is crucial for the killing of bacteria and fungi. Defects in the respiratory burst can lead to recurrent infections, particularly with organisms such as Aspergillus species, Pseudomonas species, and Staphylococcus aureus, which are commonly encountered in patients with impaired phagocyte function. The other options are not likely to be dysfunctional in this patient: (A) Lymphocytes: Lymphocytes are not directly involved in the respiratory burst and are not responsible for the patient's recurrent infections. (B) Immunoglobulin class switching: Immunoglobulin class switching is a process that occurs in B cells and is involved in the production of different classes of antibodies. It is not directly related to the respiratory burst or phagocytic cell function. (C) Superoxide dismutase: Superoxide dismutase is an enzyme that helps to neutralize superoxide radicals produced during the respiratory burst. Dysfunction of superoxide dismutase would not directly lead to a failure of neutrophils to react during the NBT test. (D) Myeloperoxidase: Myeloperoxidase is an enzyme found in neutrophils that is involved in the production of reactive oxygen species. However, dysfunction of myeloperoxidase would not directly lead to a failure of neutrophils to react during the NBT test. | |||
28 | A 3-year-old boy presents to the emergency department with a ‘cough-like-a-seal bark’ and a high-pitched inspiratory noise that is audible without a stethoscope. His mother reports that his cough has worsened over the last few hours. The patient's blood pressure is 118/78 mm Hg, pulse is 90/min, respiratory rate is 35/min, and temperature is 38.3°C (101.1°F). On physical examination, the boy is sitting and leaning forward in apparent respiratory distress with suprasternal and intercostal retractions. Auscultation reveals inspiratory stridor without wheezing. He has a frequent barking cough and a hoarse voice when he speaks. What is a chest X-ray likely to show? Options: (A): Diffuse streaky infiltrates (B): Increased interstitial markings (C): Lobar consolidation in the lingual (D): Thumbprint sign on the lateral image (E): Steeple sign | Steeple sign | Correct | The correct answer is (E) Steeple sign. Explanation: Based on the given information, the 3-year-old boy presents with a "cough-like-a-seal bark" and a high-pitched inspiratory noise audible without a stethoscope. He also has suprasternal and intercostal retractions, inspiratory stridor, and a hoarse voice. These symptoms are consistent with croup, which is a viral infection that causes inflammation of the upper airway, particularly the larynx and trachea. A chest X-ray in croup is not typically necessary for diagnosis, but it may be done to rule out other causes or complications. The characteristic finding on a chest X-ray in croup is the "steeple sign." This refers to symmetric narrowing of the supraglottic airway, resembling the shape of a steeple. The steeple sign is caused by edema and inflammation of the larynx and trachea. Therefore, a chest X-ray in this 3-year-old boy with croup is likely to show the steeple sign, which is the narrowing of the supraglottic airway. | |||
29 | A 26-year-old woman presents to a gynecologist after a missed period. After performing a complete physical examination and a screening test for pregnancy, her gynecologist informs her that she is pregnant. She is very surprised as she has been taking oral contraceptives regularly. When the gynecologist asks her about the consumption of any other medications, she mentions that she was placed on treatment for pulmonary tuberculosis (TB) 2 months ago. Her current anti-TB regimen includes rifampin, isoniazid, pyrazinamide, and ethambutol. Which of the following mechanisms best explains the failure of oral contraceptives in this patient? Options: (A): Induction of CYP3A4 by rifampin leading to decreased serum levels of ethinylestradiol and progesterone (B): Induction of CYP2A6 by rifampin leading to increased inactivation of ethinylestradiol (C): Induction of CYP2E1 by isoniazid leading to decreased serum levels of progesterone (D): Interference with the intestinal absorption of the oral contraceptive by pyrazinamide (E): Increased renal elimination of the progesterone component of the oral contraceptive by ethambutol | Induction of CYP3A4 by rifampin leading to decreased serum levels of ethinylestradiol and progesterone | Correct | The correct choice is (A) Induction of CYP3A4 by rifampin leading to decreased serum levels of ethinylestradiol and progesterone. Explanation: Rifampin, one of the medications in the patient's anti-TB regimen, is a potent inducer of hepatic metabolism. It specifically induces the cytochrome P450 enzyme CYP3A4, which is responsible for the metabolism of many drugs, including oral contraceptives. Induction of CYP3A4 by rifampin leads to increased metabolism and decreased serum levels of ethinylestradiol and progesterone, the active components of oral contraceptives. This can result in decreased contraceptive efficacy and failure of oral contraceptives. It is important for healthcare providers to counsel patients on the potential drug interactions between rifampin and oral contraceptives and recommend alternative methods of contraception during TB treatment. | |||
30 | A 4-year-old previously healthy boy presents with 4 days of intermittent vomiting and 5-6 daily loose stools. His mother noted bloody stools and decreased oral intake of food and water over the last 24 hours. He is normally in daycare; however, he has been home for the past 3 days. On physical exam his temperature is 102.2°F (39°C), blood pressure is 140/90 mmHg, pulse is 120/min, respirations are 22/min and O2 saturation is 99% on room air. He has dry mucous membranes. On abdominal exam you note diffuse tenderness to palpation without rebound or guarding. There are no masses, hepatosplenomegaly, and bowel sounds are hyperactive. Ultrasound of the right lower quadrant is negative for appendicitis. Stool is guaiac positive. He receives 15mg/kg acetaminophen and fluids are started. The next day, he complains of lower extremity weakness and tingling. On repeat exam, lower extremity strength is 3/5 with diminished patellar deep tendon reflexes. Which of the following lab findings would most likely be seen in this patient? Options: (A): Gram stain positive CSF (B): Peripheral eosinophilia (C): Xanthochromia on cerebrospinal fluid analysis (D): Increased cerebrospinal fluid protein with normal cell count (E): Oligoclonal bands on cerebrospinal fluid analysis | Increased cerebrospinal fluid protein with normal cell count | Correct | The correct choice is (D) Increased cerebrospinal fluid protein with normal cell count. Explanation: The patient's presentation is consistent with a diagnosis of Guillain-Barré syndrome (GBS), which is an acute inflammatory demyelinating polyradiculoneuropathy. GBS is often preceded by an infection, such as a gastrointestinal or respiratory infection, which can trigger an autoimmune response leading to inflammation and demyelination of peripheral nerves. The patient's symptoms of lower extremity weakness and tingling, along with diminished deep tendon reflexes, are characteristic of GBS. In GBS, the cerebrospinal fluid (CSF) analysis typically shows an increased protein level with a normal cell count. This is known as albuminocytologic dissociation and is a hallmark finding in GBS. The increased protein level is due to the breakdown of myelin in the peripheral nerves, leading to an influx of protein into the CSF. The normal cell count indicates that there is no significant inflammation in the CSF. The other options are not consistent with the presentation of GBS. Gram stain positive CSF is more suggestive of bacterial meningitis, which would typically present with fever, neck stiffness, and altered mental status. Peripheral eosinophilia is seen in parasitic infections or allergic reactions, but it is not a characteristic finding in GBS. Xanthochromia on CSF analysis is seen in subarachnoid hemorrhage, not GBS. Oligoclonal bands on CSF analysis are seen in multiple sclerosis, which presents with a different set of symptoms and findings compared to GBS. | |||
31 | A 3-week-old male newborn is brought to the physician because of an inward turning of his left forefoot. He was born at 38 weeks' gestation by cesarean section because of breech presentation. The pregnancy was complicated by oligohydramnios. Examination shows concavity of the medial border of the left foot with a skin crease just below the ball of the great toe. The lateral border of the left foot is convex. The heel is in neutral position. Tickling the lateral border of the foot leads to correction of the deformity. The remainder of the examination shows no abnormalities. X-ray of the left foot shows an increased angle between the 1st and 2nd metatarsal bones. Which of the following is the most appropriate next step in the management of this patient? Options: (A): Foot abduction brace (B): Osteotomy of the metatarsals (C): Arthrodesis of the forefoot (D): Reassurance (E): Tarsometatarsal capsulotomy | Reassurance | Correct | The correct choice is (D) Reassurance. Explanation: Based on the information provided, the newborn has a positional deformity known as metatarsus adductus. Metatarsus adductus is characterized by inward turning of the forefoot, concavity of the medial border of the foot, and a skin crease just below the ball of the great toe. The lateral border of the foot is convex. The heel is in a neutral position. Tickling the lateral border of the foot leads to correction of the deformity, indicating that it is a flexible deformity. Metatarsus adductus is a common condition in newborns and usually resolves spontaneously without treatment during the first year of life. Therefore, the most appropriate next step in the management of this patient is reassurance. No intervention is necessary at this time. Foot abduction brace (option A) is not indicated for metatarsus adductus as it is a flexible deformity that typically resolves without treatment. Osteotomy of the metatarsals (option B) and arthrodesis of the forefoot (option C) are surgical interventions that are not necessary for metatarsus adductus, especially in a newborn. These options are more appropriate for severe or rigid deformities that do not correct with conservative measures. Tarsometatarsal capsulotomy (option E) is a surgical procedure used for the correction of rigid metatarsus adductus. It is not indicated in this case as the deformity is flexible and corrects with stimulation. Therefore, the correct answer is (D) Reassurance. | |||
32 | A 42-year-old woman comes to the emergency department because of a 2-day history of right upper abdominal pain and nausea. She is 163 cm (5 ft 4 in) tall and weighs 91 kg (200 lb); her BMI is 34 kg/m2. Her temperature is 38.5°C (101.3°F). Physical examination shows a distended abdomen and right upper quadrant tenderness with normal bowel sounds. Laboratory studies show: Leukocyte count 14,000/mm3 Serum Total bilirubin 1.1 mg/dL AST 32 U/L ALT 40 U/L Alkaline phosphatase 68 U/L Abdominal ultrasonography is performed, but the results are inconclusive. Cholescintigraphy shows the intrahepatic bile ducts, hepatic ducts, common bile duct, and proximal small bowel. Which of the following is the most likely cause of this patient's symptoms?" Options: (A): Autodigestion of pancreatic parenchyma (B): Hypomotility of the gallbadder (C): Fistula between the gallbladder and small intestine (D): Infection with a hepatotropic virus (E): Obstruction of the cystic duct | Obstruction of the cystic duct | Correct | The correct answer is (E): Obstruction of the cystic duct. Explanation: The patient's symptoms, including right upper abdominal pain, nausea, and a distended abdomen, are consistent with biliary colic, which is typically caused by obstruction of the cystic duct. This obstruction can lead to distention of the gallbladder and increased pressure, resulting in pain. The patient's laboratory studies are also consistent with biliary colic, as there is no significant elevation in liver enzymes or bilirubin levels. The inconclusive abdominal ultrasonography and the findings on cholescintigraphy further support the diagnosis of cystic duct obstruction. | |||
33 | A 72-year-old woman is admitted to the intensive care unit for shortness of breath and palpitations. A cardiac catheterization is performed and measurements of the left ventricular volume and pressure at different points in the cardiac cycle are obtained. The patient's pressure-volume loop (gray) is shown with a normal pressure-volume loop (black) for comparison. Which of the following is the most likely underlying cause of this patient's symptoms? Options: (A): Mitral valve regurgitation (B): Increased systemic vascular resistance (C): Increased ventricular wall stiffness (D): Impaired left ventricular contractility (E): Aortic stenosis | Increased ventricular wall stiffness | Correct | The correct choice is (C) Increased ventricular wall stiffness. Explanation: The pressure-volume loop is a graphical representation of the changes in left ventricular pressure and volume throughout the cardiac cycle. In a normal pressure-volume loop, the ventricle fills during diastole (lower left portion of the loop) and then contracts during systole (upper right portion of the loop) to eject blood into the systemic circulation. In this patient's pressure-volume loop, the loop is narrower and more elongated, indicating decreased ventricular compliance and increased ventricular stiffness. This increased stiffness impairs the ventricle's ability to fill adequately during diastole, leading to decreased stroke volume and cardiac output. This can result in symptoms such as shortness of breath and palpitations. Mitral valve regurgitation (A) would typically result in a wider pressure-volume loop, as blood would flow back into the left atrium during systole. Increased systemic vascular resistance (B) would increase the afterload on the ventricle, resulting in a higher pressure-volume loop. Impaired left ventricular contractility (D) would result in a smaller pressure-volume loop, as the ventricle would have difficulty ejecting blood. Aortic stenosis (E) would result in a narrower pressure-volume loop, but the loop would be more circular in shape rather than elongated. | |||
34 | A 22-year-old woman is brought to the emergency department because of a 2-day history of fever, intermittent rigors, and night sweats. She also has a 1-month history of progressive fatigue. Five weeks ago, she was hospitalized and received intravenous antibiotics for treatment of bacterial meningitis while visiting relatives in Guatemala. Her temperature is 39.4°C (102.9°F), pulse is 130/min, and blood pressure is 105/70 mm Hg. Examination shows pallor and scattered petechiae and ecchymoses. Laboratory studies show a hemoglobin concentration of 9.0 g/dL, a leukocyte count of 1,100/mm3 with 30% segmented neutrophils, and a platelet count of 20,000/mm3 . Blood cultures grow coagulase-negative staphylococci. The patient was most likely treated with which of the following antibiotics? Options: (A): Doxycycline (B): Trimethoprim/sulfamethoxazole (C): Vancomycin (D): Linezolid (E): Chloramphenicol | Chloramphenicol | Correct | The correct choice is (E) Chloramphenicol. Explanation: Based on the patient's history and presentation, she most likely developed a condition called aplastic anemia as a complication of her previous bacterial meningitis treatment. Aplastic anemia is a rare but serious side effect of certain medications, including chloramphenicol. The patient's symptoms of fever, fatigue, and night sweats, along with her low blood counts (low hemoglobin, leukocyte count, and platelet count), are consistent with aplastic anemia. The presence of petechiae and ecchymoses suggests a bleeding tendency, which is also seen in aplastic anemia due to the low platelet count. Chloramphenicol is known to cause bone marrow suppression, leading to aplastic anemia. It is important to note that chloramphenicol is rarely used in the United States due to its potential for serious side effects, including aplastic anemia. However, it is still used in some parts of the world, including Guatemala, where the patient was visiting. The other antibiotic options listed (doxycycline, trimethoprim/sulfamethoxazole, vancomycin, and linezolid) are not associated with the development of aplastic anemia. Doxycycline is a tetracycline antibiotic commonly used for various infections. Trimethoprim/sulfamethoxazole is a combination antibiotic used for urinary tract infections and other bacterial infections. Vancomycin is a glycopeptide antibiotic used for serious infections caused by gram-positive bacteria. Linezolid is an oxazolidinone antibiotic used for certain resistant infections, such as methicillin-resistant Staphylococcus aureus (MRSA). Therefore, the most likely antibiotic that the patient was treated with is chloramphenicol, which can cause aplastic anemia as a side effect. | |||
35 | An otherwise healthy 50-year-old man comes to the physician because of a 6-month history of increasingly frequent episodes of upper abdominal pain, nausea, vomiting, and diarrhea. He has had a 3.2-kg (7-lb) weight loss during this time. Physical examination shows bilateral pitting pedal edema. An endoscopy shows prominent rugae in the gastric fundus. Biopsy shows parietal cell atrophy. Which of the following is the most likely underlying cause? Options: (A): Serotonin-secreting gastric tumor (B): Proliferation of gastric mucus-producing cells (C): Neoplasia of submucosal lymphoid tissue (D): Excessive somatostatin secretion (E): Ectopic secretion of gastrin | Proliferation of gastric mucus-producing cells | Correct | The correct choice is (B) Proliferation of gastric mucus-producing cells. Explanation: The patient's symptoms of upper abdominal pain, nausea, vomiting, and diarrhea, along with the weight loss, suggest a gastrointestinal disorder. The physical examination findings of bilateral pitting pedal edema indicate fluid retention, which can be seen in conditions associated with protein loss, such as malabsorption. The endoscopic findings of prominent rugae in the gastric fundus and biopsy showing parietal cell atrophy are consistent with Menetrier disease. Menetrier disease is a rare disorder characterized by hypertrophy of the gastric mucosa, leading to excessive mucus production. This proliferation of gastric mucus-producing cells results in the formation of large gastric folds (rugae) and parietal cell atrophy. The excessive mucus production can lead to protein loss, causing hypoalbuminemia and subsequent fluid retention, as seen in this patient with bilateral pitting pedal edema. The other options are not consistent with the clinical presentation and findings. Serotonin-secreting gastric tumors (option A) can cause symptoms such as diarrhea and flushing, but they do not typically cause parietal cell atrophy or prominent rugae. Neoplasia of submucosal lymphoid tissue (option C) is not associated with the clinical findings described. Excessive somatostatin secretion (option D) would lead to decreased gastric acid secretion and would not cause the symptoms and findings seen in this patient. Ectopic secretion of gastrin (option E) would lead to increased gastric acid secretion and would not cause the parietal cell atrophy seen in this patient. | |||
36 | A 27-year-old man presents to the emergency department. He was brought in by staff from the homeless shelter when they found him unresponsive. The patient is a known IV drug abuser but otherwise has an unknown past medical history. He currently attends a methadone clinic. His temperature is 99.5°F (37.5°C), blood pressure is 97/48 mmHg, pulse is 140/min, respirations are 29/min, and oxygen saturation is 98% on room air. Initial laboratory values are shown below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 6.3 mEq/L HCO3-: 17 mEq/L Glucose: 589 mg/dL The patient is given treatment. After treatment, his temperature is 99.5°F (37.5°C), blood pressure is 117/78 mmHg, pulse is 100/min, respirations are 23/min, and oxygen saturation is 98% on room air. His laboratory values are seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 4.3 mEq/L HCO3-: 19 mEq/L Glucose: 90 mg/dL Which of the following is the best next step in management? Options: (A): Insulin, IV fluids, and potassium (B): Insulin, potassium, IV fluids, and glucose (C): IV fluids only (D): Oral rehydration (E): Supportive therapy and close monitoring | Insulin, potassium, IV fluids, and glucose | Correct | The correct answer is (B): Insulin, potassium, IV fluids, and glucose. Explanation: The patient's initial presentation with unresponsiveness, tachycardia, hypotension, and laboratory findings of hyperglycemia (glucose 589 mg/dL) and severe hyperkalemia (K+ 6.3 mEq/L) is consistent with diabetic ketoacidosis (DKA). DKA is a life-threatening complication of uncontrolled diabetes mellitus, characterized by insulin deficiency and an increase in counter-regulatory hormones (glucagon, cortisol, catecholamines, growth hormone). The lack of insulin leads to increased lipolysis and ketogenesis, resulting in metabolic acidosis. The increased counter-regulatory hormones also lead to increased gluconeogenesis and glycogenolysis, causing hyperglycemia. The hyperglycemia leads to osmotic diuresis and subsequent dehydration. The dehydration, along with the metabolic acidosis, leads to electrolyte abnormalities, including hyperkalemia. The initial management of DKA involves the administration of IV fluids, insulin, and potassium. IV fluids are given to correct the dehydration and improve tissue perfusion. Insulin is administered to reverse the ketogenesis and promote glucose uptake by cells. Potassium is given to correct the total body potassium deficit and prevent hypokalemia, which can occur as a result of insulin therapy. The administration of glucose is not necessary initially because the patient already has hyperglycemia. Giving glucose without insulin can worsen the hyperglycemia and exacerbate the metabolic acidosis. Therefore, the correct next step in management is to administer insulin, potassium, IV fluids, and withhold glucose. | |||
37 | A 67-year-old man who was diagnosed with arthritis 16 years ago presents with right knee swelling and pain. His left knee was swollen a few weeks ago, but now with both joints affected, he has difficulty walking and feels frustrated. He also has back pain which makes it extremely difficult to move around and be active during the day. He says his pain significantly improves with rest. He also suffers from dandruff for which he uses special shampoos. Physical examination is notable for pitting of his nails. Which of the following is the most likely diagnosis? Options: (A): Psoriatic arthritis (B): Arthritis mutilans (C): Rheumatoid arthritis (D): Familial mediterranean fever (E): Mixed connective tissue disease | Psoriatic arthritis | Correct | The correct choice is (A) Psoriatic arthritis. Explanation: The patient's presentation is consistent with psoriatic arthritis. Psoriatic arthritis is a chronic inflammatory arthritis that occurs in individuals with psoriasis. The patient's history of arthritis for 16 years, along with the presence of joint swelling and pain in both knees, is suggestive of a chronic inflammatory arthritis. The improvement of pain with rest is a characteristic feature of psoriatic arthritis. The patient's back pain is also a common manifestation of psoriatic arthritis, as it can affect the spine and sacroiliac joints. The presence of dandruff and pitting of the nails further supports the diagnosis of psoriatic arthritis, as these are common dermatologic manifestations of psoriasis. Arthritis mutilans (B) is a severe form of psoriatic arthritis characterized by rapid and destructive joint involvement, which is not described in this patient. Rheumatoid arthritis (C) typically presents with symmetric joint involvement and is less likely in this case. Familial Mediterranean fever (D) is an autosomal recessive disorder characterized by recurrent episodes of fever and serositis, and is not associated with psoriasis or joint involvement. Mixed connective tissue disease (E) is characterized by features of multiple autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, and polymyositis, and is less likely in this patient. | |||
38 | A 65-year-old woman schedules an appointment with her physician for evaluation of weight loss and weakness. The weakness is more noticeable when climbing stairs and combing hair. The weakness improves after brief exercise. She also has bladder incontinence for the past 4 weeks and was given an anticholinesterase agent with no improvement. What is the most likely cause of the symptoms? Options: (A): Botulism (B): Duchenne muscular dystrophy (C): Hypothyroidism (D): Myasthenia gravis (E): Paraneoplastic syndrome from small cell carcinoma of the lung | Paraneoplastic syndrome from small cell carcinoma of the lung | Correct | The correct answer is (E): Paraneoplastic syndrome from small cell carcinoma of the lung. Explanation: The patient's symptoms of weight loss, weakness, and bladder incontinence are concerning for a neurological disorder. The weakness being more noticeable when climbing stairs and combing hair, and improving after brief exercise, suggests a myopathic process. The lack of improvement with an anticholinesterase agent also points away from myasthenia gravis. Paraneoplastic syndromes are a group of disorders that occur as a result of an immune response to a malignancy. In this case, the small cell carcinoma of the lung is likely causing the paraneoplastic syndrome, which is characterized by muscle weakness and weight loss. Bladder incontinence can also be seen in paraneoplastic syndromes. Botulism is caused by the toxin produced by Clostridium botulinum and typically presents with symmetric descending flaccid paralysis, which is not consistent with the patient's symptoms. Duchenne muscular dystrophy is an X-linked recessive disorder that presents in childhood with progressive muscle weakness and wasting. It is unlikely to be the cause of the patient's symptoms at her age. Hypothyroidism can cause muscle weakness, but it is not typically associated with bladder incontinence. Additionally, the patient's symptoms are more consistent with a myopathic process rather than a primary endocrine disorder. | |||
39 | A 3-month-old boy presents to his pediatrician with persistent diarrhea, oral candidiasis, and signs and symptoms suggestive of respiratory syncytial virus (RSV) pneumonia. His weight is in the 10th percentile. He is being evaluated for an immunodeficiency disease. Laboratory results for the HIV are negative by PCR. Which of the following is the most likely cause of these findings in this patient? Options: (A): Defective T cell function (B): Grossly reduced levels of B cells (C): An X-linked inheritance of HLA genes (D): Defective isotype switching (E): Selective IgA deficiency | Defective T cell function | Correct | The correct answer is (A) Defective T cell function. Explanation: The patient's presentation of persistent diarrhea, oral candidiasis, and signs and symptoms of RSV pneumonia, along with a weight in the 10th percentile, suggests an immunodeficiency. The most likely cause of these findings is a defect in T cell function. T cells play a crucial role in the immune response, particularly in cell-mediated immunity. Defects in T cell function can lead to recurrent infections, including respiratory infections and opportunistic infections such as oral candidiasis. Additionally, T cells are involved in regulating the immune response and can help control viral infections like RSV. The other options are less likely causes of the patient's presentation: (B) Grossly reduced levels of B cells: While B cell deficiencies can also lead to recurrent infections, the presence of oral candidiasis and signs of RSV pneumonia suggest a defect in T cell function rather than a primary B cell deficiency. (C) An X-linked inheritance of HLA genes: HLA genes are involved in the immune response, but an X-linked inheritance of HLA genes is not a known cause of immunodeficiency. (D) Defective isotype switching: Isotype switching refers to the process by which B cells change the type of antibody they produce. While defects in isotype switching can lead to antibody deficiencies, the patient's presentation suggests a defect in T cell function rather than a primary antibody deficiency. (E) Selective IgA deficiency: IgA deficiency is a common primary immunodeficiency, but it typically presents with recurrent respiratory and gastrointestinal infections, rather than the specific findings seen in this patient. | |||
40 | A 53-year-old man with recurrent pancreatic adenocarcinoma is enrolled in a clinical trial for a novel chemotherapeutic agent that his physician believes may be beneficial to his condition. The novel drug was previously tested in a small population and is now undergoing a larger phase 3 trial in preparation for FDA approval. A dose-response trial had the following results: 10 mg dose - 6/59 patients demonstrated improvement 20 mg dose - 19/49 patients demonstrated improvement 30 mg dose - 26/53 patients demonstrated improvement 40 mg dose - 46/51 patients demonstrated improvement The same trial also had the following safety profile: 20 mg dose - 5/49 patients had a treatment related adverse event 40 mg dose - 11/51 patients had a treatment related adverse event 60 mg dose - 15/42 patients had a treatment related adverse event 80 mg dose - 23/47 patients had a treatment related adverse event 100 mg dose - 47/52 patients had a treatment related adverse event Based on this study, which of the following represents the most likely therapeutic index for this novel chemotherapeutic agent? Options: (A): 0.375 (B): 0.5 (C): 2 (D): 2.5 (E): 2.67 | 2.67 | Incorrect | The therapeutic index is a measure of the safety and efficacy of a drug. It is calculated by dividing the number of patients who demonstrated improvement by the number of patients who experienced a treatment-related adverse event. Let's calculate the therapeutic index for each dose: 10 mg dose: 6/59 = 0.102 20 mg dose: 19/49 = 0.388 30 mg dose: 26/53 = 0.491 40 mg dose: 46/51 = 0.902 Based on these calculations, the 40 mg dose has the highest therapeutic index of 0.902. Therefore, the most likely therapeutic index for this novel chemotherapeutic agent is (D) 2.5. | |||
41 | A 67-year-old male is seen by neurology after he was noticed to be speaking strangely by his family. After acute treatment with tissue plasminogen activator (tPA), the patient is able to recover most of his speech. Subsequent neurologic exam finds that the patient is fluent while speaking and is able to comprehend both one and two step instructions. Noticeably the patient remains unable to complete tasks involving verbal repetition. Residual damage to which of the following structures is most likely responsible for this patient's syndrome? Options: (A): Arcuate fasciculus (B): Inferior frontal gyrus (C): Superior temporal gyrus (D): Inferior frontal gyrus + superior temporal gyrus (E): Arcuate fasciculus + inferior frontal gyrus + superior temporal gyrus | Arcuate fasciculus | Correct | The correct choice is (A) Arcuate fasciculus. Explanation: The patient's symptoms of fluent speech, comprehension of one and two-step instructions, and difficulty with verbal repetition are consistent with a condition known as conduction aphasia. Conduction aphasia is typically caused by damage to the arcuate fasciculus, a white matter tract that connects the posterior superior temporal gyrus (Wernicke's area) with the inferior frontal gyrus (Broca's area). The arcuate fasciculus is responsible for transmitting information between these two language areas, allowing for the repetition of spoken language. Damage to the arcuate fasciculus disrupts this connection, resulting in the inability to repeat words or phrases accurately. In this case, the patient's ability to comprehend and produce fluent speech suggests that the inferior frontal gyrus and superior temporal gyrus are intact. Therefore, the most likely cause of the patient's syndrome is residual damage to the arcuate fasciculus. | |||
42 | A 27-year-old woman presents to the office with concerns about her long struggle with her physical appearance since adolescence. She says she has always been "large" and was constantly targeted by her classmates and coworkers for being so. Her main concern at the moment is her acne and unwanted facial hair on her upper lip, for which she often visits a local spa. She has tried numerous diet plans, exercise regimens, and cosmetic products with little to no effect. Recently, she underwent a glucose tolerance test that showed a plasma glucose level of 160 mg/dL (8.9 mmol/L) after 2 hours of a 75 g dose of oral glucose. She has a family history of type 2 diabetes mellitus and a menstrual cycle that occurs every 45 days. Her pulse is 72/min and the blood pressure is 138/80 mm Hg. On physical examination, her height is 160 cm (5 ft 3 in) and her weight is 85 kg (187 lb), and she has severe inflammatory acne over the cheeks and forehead and dark coarse hairs on the back. What is the most likely diagnosis of this patient? Options: (A): Hypothyroidism (B): Idiopathic hirsutism (C): Cushing's disease (D): Polycystic ovarian syndrome (PCOS) (E): Ovarian hyperthecosis | Polycystic ovarian syndrome (PCOS) | Correct | The correct answer is (D) Polycystic ovarian syndrome (PCOS). Explanation: This patient's presentation is consistent with polycystic ovarian syndrome (PCOS). PCOS is a common endocrine disorder characterized by hyperandrogenism, chronic anovulation, and polycystic ovaries on ultrasound. The patient's history of long-standing struggles with her physical appearance, including unwanted facial hair and acne, are classic signs of hyperandrogenism. Additionally, her menstrual cycle occurring every 45 days suggests anovulation. The presence of severe inflammatory acne and dark coarse hairs on the back further support the diagnosis of PCOS. The patient's glucose tolerance test result of a plasma glucose level of 160 mg/dL (8.9 mmol/L) after 2 hours is consistent with impaired glucose tolerance, which is commonly seen in patients with PCOS. The family history of type 2 diabetes mellitus also increases the likelihood of PCOS as the underlying cause. Hypothyroidism (option A) can cause weight gain and menstrual irregularities, but it does not typically present with hyperandrogenism or polycystic ovaries. Idiopathic hirsutism (option B) refers to excessive hair growth in women without any identifiable cause. However, this patient's presentation is more consistent with PCOS, which is a common cause of hirsutism. Cushing's disease (option C) is characterized by excessive cortisol production, which can lead to weight gain, acne, and hirsutism. However, this patient does not have the typical features of Cushing's disease, such as central obesity, thinning of the skin, or easy bruising. Ovarian hyperthecosis (option E) is a rare condition characterized by hyperplasia of the ovarian stroma and excessive androgen production. It typically presents with severe hirsutism and virilization, which are not prominent features in this patient's presentation. | |||
43 | А 43-уеаr-old mаn рrеѕеntѕ wіth tіnglіng аnd numbnеѕѕ of the lowеr lіmbѕ for 2 wееkѕ. Не also сomрlаіnѕ of реrѕіѕtеnt раіn in his legs whісh is not relieved by over-the-counter analgesics. Past medical history is significant for type 2 dіаbеtes mellitus for 2 уеаrѕ, inconsistently managed with mеtformіn аnd glіmеріrіdе. Оn physical ехаmіnаtіon, thеrе іѕ dесrеаѕеd ѕеnѕаtіon to pain in both lower lіmbs, but deep tеndon rеflехеѕ аrе іntасt. Ніѕ vіtаl ѕіgnѕ include: blood рrеѕѕurе 122/84 mm Нg, tеmреrаturе 36.7°C (98.1°F), and rеѕріrаtorу rаtе 10/mіn. His ankle-brachial pressure index (ABPI) on the right side is 1.1. His blood sugar analyses are as follows: Fasting 141 mg/ dL 2 hours Post-Prandial 235 mg/ dL HbA1c 8.1% Which of the following is the best measure to prevent the progression of the symptoms present in this patient? Options: (A): Use of atorvastatin (B): Femoro-Ileal artery bypass (C): Strict blood glucose control (D): Strict control of blood pressure (E): Lower limb amputation | Strict blood glucose control | Correct | The correct answer is (C) Strict blood glucose control. Explanation: The patient in this case has a history of type 2 diabetes mellitus and is experiencing symptoms of peripheral neuropathy, such as tingling, numbness, and persistent pain in the lower limbs. These symptoms are likely due to uncontrolled diabetes and high blood sugar levels. Strict blood glucose control is the best measure to prevent the progression of these symptoms. By maintaining tight control of blood sugar levels, the patient can prevent further damage to the nerves and potentially even reverse some of the existing symptoms. This can be achieved through lifestyle modifications, such as a healthy diet and regular exercise, as well as medication management, including consistent use of prescribed diabetes medications like metformin and glimepiride. The other options listed are not appropriate for managing the symptoms of peripheral neuropathy in this patient: (A) Use of atorvastatin: Atorvastatin is a medication used to lower cholesterol levels and is not indicated for the treatment of peripheral neuropathy. (B) Femoro-Ileal artery bypass: This surgical procedure is used to bypass blocked or narrowed arteries in the legs, typically in cases of peripheral arterial disease. While peripheral arterial disease can cause similar symptoms to peripheral neuropathy, the patient's ankle-brachial pressure index (ABPI) is normal, indicating that arterial blood flow is not compromised. Therefore, a bypass procedure is not necessary in this case. (D) Strict control of blood pressure: While it is important to manage blood pressure in patients with diabetes, strict control of blood pressure alone will not address the underlying cause of the patient's symptoms, which is uncontrolled blood sugar levels. (E) Lower limb amputation: Amputation is a last resort option for severe cases of peripheral neuropathy that do not respond to other treatments. It is not appropriate or necessary in this patient's case, as his symptoms can be managed and potentially reversed with strict blood glucose control. | |||
44 | A one-day-old male is evaluated in the hospital nursery for bilious vomiting. The patient has urinated multiple times since birth but has not yet passed meconium. He was born at 38 weeks gestation to a 36-year-old gravida 3 via vaginal delivery. The pregnancy was complicated by gestational diabetes. The patient’s mother received routine prenatal care and declined first trimester screening. She subsequently underwent a quadruple screen at 15 weeks gestation that demonstrated decreased maternal serum alpha-fetoprotein (AFP), increased beta-hCG, decreased unconjugated estriol, and increased inhibin A. Her last ultrasound prior to onset of labor demonstrated an amniotic fluid index (AFI) of 28 cm. The patient’s two older siblings are both healthy. The patient’s temperature is 97.8°F (36.6°C), blood pressure is 58/37 mmHg, pulse is 166/min, and respirations are 38/min. On physical exam, the patient is in moderate distress. His abdomen is firm and distended with hypoactive bowel sounds. Which of the following is the most likely etiology of this fetus’s presentation? Options: (A): Duodenal atresia (B): Intestinal malrotation (C): Meconium ileus (D): Necrotizing enterocolitis (E): Pyloric stenosis | Duodenal atresia | Correct | The correct choice is (A) Duodenal atresia. Explanation: The presentation of bilious vomiting in a one-day-old male with no passage of meconium is highly suggestive of an obstruction in the gastrointestinal tract. Duodenal atresia is a congenital malformation characterized by the complete or partial obstruction of the duodenum. It is commonly associated with other anomalies, such as Down syndrome and other chromosomal abnormalities. The maternal serum screening findings in this case, including decreased AFP and increased beta-hCG, are consistent with an increased risk of chromosomal abnormalities. The presence of polyhydramnios, as indicated by the amniotic fluid index (AFI) of 28 cm, is also commonly seen in cases of duodenal atresia due to impaired swallowing of amniotic fluid. The patient's symptoms of bilious vomiting, abdominal distention, and hypoactive bowel sounds further support the diagnosis of duodenal atresia. Intestinal malrotation, meconium ileus, necrotizing enterocolitis, and pyloric stenosis are less likely to present with bilious vomiting in the neonatal period. | |||
45 | A healthy 23-year-old male is undergoing an exercise stress test as part of his physiology class. If blood were to be sampled at different locations before and after the stress test, which area of the body would contain the lowest oxygen content at both time points? Options: (A): Superior vena cava (B): Inferior vena cava (C): Coronary sinus (D): Pulmonary artery (E): Pulmonary vein | Coronary sinus | Correct | The correct choice is (C) Coronary sinus. Explanation: During exercise, the body requires more oxygen to meet the increased metabolic demands. As a result, oxygen is extracted from the blood by the tissues, leading to a decrease in oxygen content. The coronary sinus is a blood vessel that collects deoxygenated blood from the heart muscle (myocardium) and returns it to the right atrium of the heart. Since the coronary sinus collects blood from the heart muscle, which has extracted oxygen for its own metabolic needs, it will have the lowest oxygen content compared to other locations. The superior vena cava (option A) carries deoxygenated blood from the upper body to the right atrium, but it does not directly collect blood from the heart muscle. Therefore, it will have a higher oxygen content compared to the coronary sinus. The inferior vena cava (option B) carries deoxygenated blood from the lower body to the right atrium. Similar to the superior vena cava, it does not directly collect blood from the heart muscle, so it will have a higher oxygen content compared to the coronary sinus. The pulmonary artery (option D) carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. It does not collect blood from the heart muscle, so it will have a higher oxygen content compared to the coronary sinus. The pulmonary vein (option E) carries oxygenated blood from the lungs to the left atrium of the heart. It does not collect blood from the heart muscle, so it will have a higher oxygen content compared to the coronary sinus. Therefore, the coronary sinus will have the lowest oxygen content at both time points before and after the exercise stress test. | |||
46 | A 45-year-old G5P4105 presents to her gynecologist’s office with six months of increasingly heavy periods. She now soaks one super absorbent tampon every two hours for five days each cycle. Her cycles have also become irregular, with intermenstrual bleeding for the last two months. She now experiences significant dysmenorrhea, requiring 400 mg ibuprofen every four hours for the majority of each menses. In addition, she reports new onset mild dyspareunia with intercourse and a “heavy feeling” in her pelvis. She has also noticed increased urinary frequency but denies bowel changes. The patient has a past medical history of obesity and type II diabetes on metformin. Her last child was born four years ago, and she has had five spontaneous vaginal deliveries. At this office visit, temperature is 98.5°F (36.9°C), blood pressure is 137/84 mmHg, pulse is 87/min, and respirations are 14/min. Which of the following physical exam findings is most likely to be present in this patient? Options: (A): Rectouterine septum nodularity (B): Globular 10-week sized uterus (C): Adnexal mass (D): Irregular 14-week sized uterus (E): No remarkable physical exam finding | Globular 10-week sized uterus | Correct | The correct choice is (B) Globular 10-week sized uterus. Explanation: The patient's history and symptoms are suggestive of a possible uterine pathology, such as uterine fibroids. Uterine fibroids are benign smooth muscle tumors that commonly occur in women of reproductive age. They can cause heavy menstrual bleeding (menorrhagia), irregular periods, and pelvic pain. The patient's symptoms of heavy periods, intermenstrual bleeding, dysmenorrhea, and a "heavy feeling" in the pelvis are consistent with uterine fibroids. On physical examination, a globular 10-week sized uterus is most likely to be present in this patient. Uterine fibroids can cause the uterus to enlarge, resulting in a palpable mass on abdominal examination. The size of the uterus is often described in terms of gestational weeks, with a 10-week sized uterus indicating that the uterus is approximately the size it would be at 10 weeks of pregnancy. Rectouterine septum nodularity (option A) is not a typical finding in uterine fibroids. It is more commonly associated with adenomyosis, which is a condition where the endometrial tissue grows into the muscular wall of the uterus. An adnexal mass (option C) is not likely to be present in this patient based on the given history and symptoms. Adnexal masses are usually associated with ovarian pathology, such as ovarian cysts or tumors. The patient's symptoms are more consistent with uterine fibroids rather than ovarian pathology. An irregular 14-week sized uterus (option D) is less likely in this patient. Uterine fibroids typically cause the uterus to enlarge symmetrically, resulting in a globular shape rather than an irregular shape. No remarkable physical exam finding (option E) is not the most likely finding in this patient. Given the patient's symptoms and history, it is expected that there would be a physical exam finding related to the uterine pathology, such as an enlarged uterus. | |||
47 | A man is brought into the emergency department by the police department. The officer state that the man has been arrested multiple times for public alcohol intoxication, but recently became homeless. On exam, the man is behaving erratically. His vitals are all within normal limits. He appears confused and has a slurred speech. On gait exam, the patient is ataxic and cannot stand without support for more than a few seconds. Labs return with the following values: Na 140, K 4, Cl 106, BUN 8, Cr 2. His ABG has pH 7.3, PaCO2 13mm, PaO2 130mm, HCO3 7. His urinalysis is shown in Figure 1. Blood salicylate levels return as normal. While you await other diagnostic tests, which of the following should be administered next to treat this patient? Options: (A): Ethanol (B): Naltrexone (C): Naloxone (D): Flumazenil (E): Fomepizole | Fomepizole | Correct | The correct choice is (E) Fomepizole. Explanation: Based on the patient's history of alcohol intoxication and the presence of ataxia, confusion, slurred speech, and abnormal labs (low HCO3 and elevated anion gap), the patient is likely experiencing alcohol withdrawal. The most appropriate treatment for alcohol withdrawal is benzodiazepines, such as diazepam or lorazepam, to control symptoms and prevent progression to severe withdrawal, which can include seizures and delirium tremens. However, none of the options provided include benzodiazepines. Fomepizole is a competitive inhibitor of alcohol dehydrogenase and is used in the treatment of methanol and ethylene glycol poisoning. While it is not the first-line treatment for alcohol withdrawal, it can be used in severe cases where benzodiazepines are not effective or contraindicated. Fomepizole inhibits the metabolism of alcohol to acetaldehyde, which can help reduce the symptoms of alcohol withdrawal. Ethanol (option A) is another treatment option for alcohol withdrawal, as it can be used to prevent withdrawal symptoms by providing a controlled amount of alcohol to the patient. However, it is not the next best step in this case, as the patient's symptoms are not severe enough to warrant immediate treatment with ethanol. Naltrexone (option B) is an opioid receptor antagonist and is used in the treatment of alcohol dependence. It is not indicated for the acute management of alcohol withdrawal. Naloxone (option C) is an opioid receptor antagonist and is used in the treatment of opioid overdose. It is not indicated for the treatment of alcohol withdrawal. Flumazenil (option D) is a benzodiazepine receptor antagonist and is used in the reversal of benzodiazepine overdose or sedation. It is not indicated for the treatment of alcohol withdrawal. Therefore, the most appropriate next step in treating this patient is to administer fomepizole (option E) to help alleviate the symptoms of alcohol withdrawal. | |||
48 | A medical research study is evaluating an investigational novel drug (medication 1) compared with standard therapy (medication 2) in patients presenting to the emergency department with myocardial infarction (MI). The study enrolled a total of 3,000 subjects, 1,500 in each study arm. Follow-up was conducted at 45 days post-MI. The following are the results of the trial: Endpoints Medication 1 Medication 2 P-Value Primary: death from cardiac causes 134 210 0.03 Secondary: hyperkalemia 57 70 0.4 What is the number needed to treat (NNT) for the primary endpoint of death from cardiac causes? (Round to the nearest whole number.) Options: (A): 5 (B): 16 (C): 20 (D): 30 (E): 50 | 20 | Correct | The correct answer is (C) 20. The number needed to treat (NNT) is a measure of the effectiveness of a treatment. It represents the number of patients that need to be treated with a specific intervention in order to prevent one additional outcome event compared to a control group. In this case, the primary endpoint is death from cardiac causes. The study results show that 134 patients in the medication 1 group died from cardiac causes, while 210 patients in the medication 2 group died from cardiac causes. To calculate the NNT, we need to calculate the absolute risk reduction (ARR), which is the difference in event rates between the two groups. The event rate in the medication 1 group is 134/1500 = 0.0893 (rounded to 4 decimal places). The event rate in the medication 2 group is 210/1500 = 0.14 (rounded to 2 decimal places). The ARR is calculated by subtracting the event rate in the medication 1 group from the event rate in the medication 2 group: 0.14 - 0.0893 = 0.0507 (rounded to 4 decimal places). The NNT is then calculated by taking the reciprocal of the ARR: 1/0.0507 = 19.7 (rounded to the nearest whole number), which is approximately 20. Therefore, the number needed to treat (NNT) for the primary endpoint of death from cardiac causes is 20. This means that for every 20 patients treated with medication 1 instead of medication 2, one additional death from cardiac causes would be prevented. | |||
49 | A 55-year-old man comes to the physician because of a 6-week history of tingling pain in the sole of his right foot when he raises it above chest level during exercises. He reports that he started exercising regularly 2 months ago and that his right calf cramps when he uses the incline feature on the treadmill, forcing him to take frequent breaks. The pain completely disappears after resting for a few minutes. He has an 8-year history of type 2 diabetes mellitus. He has smoked two packs of cigarettes daily for 34 years. His only medication is metformin. His pulse is 82/min, and blood pressure is 170/92 mm Hg. Straight leg raise test elicits pallor and tingling pain in the right foot. There is no pain in the back. His muscle strength is normal. Femoral pulses are palpable; right pedal pulses are absent. Which of the following is the most likely diagnosis? Options: (A): Femoropopliteal artery stenosis (B): Vasculitis of the right popliteal artery (C): Acute thrombosis of right popliteal vein (D): Lumbar spinal stenosis (E): Aortoiliac artery stenosis " | Femoropopliteal artery stenosis | Correct | The correct choice is (A) Femoropopliteal artery stenosis. Explanation: The patient's symptoms, including tingling pain in the sole of the right foot during exercise and calf cramps with incline treadmill use, are consistent with exercise-induced ischemia. The absence of right pedal pulses suggests arterial insufficiency. The most likely cause of these findings in this patient is atherosclerotic occlusive disease of the femoropopliteal artery. Risk factors for atherosclerosis, such as smoking and diabetes mellitus, are present. The straight leg raise test elicits pallor and tingling pain in the right foot, further supporting the diagnosis of arterial insufficiency. The absence of back pain and normal muscle strength make lumbar spinal stenosis an unlikely cause. Vasculitis of the right popliteal artery and acute thrombosis of the right popliteal vein would not explain the absence of right pedal pulses. Aortoiliac artery stenosis would not explain the absence of right pedal pulses. | |||
50 | A 29-year-old primigravid woman at 35 weeks' gestation is admitted to the hospital in labor. She has no history of serious medical illness. She has had an uncomplicated pregnancy. Her last ultrasound at 22 weeks' gestation was normal. On admission, fetal heartbeats cannot be detected by fetal doppler monitor. Ultrasound shows decreased amniotic fluid levels and no evidence of fetal movement, respiration, or heart activity. The patient gives birth to a 2296 g (5 lb 1 oz) male infant. Physical examination shows no signs of life. There are no visible malformations. The placenta is unremarkable. Which of the following is the most appropriate next step in management? Options: (A): Perform karyotyping of amniotic fluid (B): Recommend autopsy of the infant (C): Obtain photographs, x-ray imaging, and MRI (D): Perform maternal antibody and thrombophilia testing (E): Obtain consent for parental genetic testing | Recommend autopsy of the infant | Correct | The correct choice is (B) Recommend autopsy of the infant. Explanation: In this scenario, the patient presents with a stillbirth at 35 weeks' gestation. The absence of fetal heartbeats, decreased amniotic fluid levels, and lack of fetal movement, respiration, or heart activity indicate fetal demise. The physical examination shows no signs of visible malformations, and the placenta is unremarkable. In cases of stillbirth, it is important to determine the cause of fetal demise to provide appropriate counseling and management for the parents and to potentially prevent future stillbirths. Autopsy of the infant is the most appropriate next step in management. Autopsy can provide valuable information about the cause of stillbirth, such as genetic abnormalities, placental abnormalities, or other factors that may have contributed to fetal demise. It can also help identify any potential risks for future pregnancies. Performing karyotyping of amniotic fluid (option A) may be considered in cases of stillbirth, but it is not the most appropriate next step in this scenario. Karyotyping is typically performed on fetal tissue, such as skin or bone, rather than amniotic fluid. Obtaining photographs, x-ray imaging, and MRI (option C) may be useful in some cases of stillbirth, but they are not the most appropriate next step in this scenario. Autopsy provides more comprehensive information about the cause of stillbirth. Performing maternal antibody and thrombophilia testing (option D) may be considered in cases of stillbirth, but it is not the most appropriate next step in this scenario. These tests are typically performed to evaluate for potential maternal factors that may have contributed to fetal demise. Obtaining consent for parental genetic testing (option E) may be considered in cases of stillbirth, but it is not the most appropriate next step in this scenario. Autopsy provides more comprehensive information about the cause of stillbirth. Therefore, the most appropriate next step in management is to recommend autopsy of the infant (option B). | |||
51 | A 67-year-old man is hospitalized after several days of fever and increasing shortness of breath. Respiratory viral panel returns positive for influenza A and the patient is started on a standard five day course of oseltamivir. Despite therapy, his shortness of breath continues to worsen and his oxygen saturation decreases to the point where ICU transfer and intubation are required. Chest radiograph shows bilateral infiltrates. Clinical criteria are consistent with development of Acute Respiratory Distress Syndrome (ARDS). After several weeks of supportive therapy, the patient improves with lung function returning to near normal. Which of the following processes is involved in the regeneration of alveolar lining after damage to alveoli occurs? Options: (A): Squamous cell proliferation (B): Sweeping of debris out of the alveoli by ciliated cells (C): Excess mucus production by goblet cells (D): Proliferation of surfactant-secreting cells (E): Proliferation of club cells | Proliferation of surfactant-secreting cells | Correct | The correct choice is (D): Proliferation of surfactant-secreting cells. Explanation: After damage to the alveoli occurs, the regeneration of the alveolar lining involves the proliferation of surfactant-secreting cells. Surfactant is a substance that helps reduce surface tension in the alveoli, preventing their collapse. Type II pneumocytes, which are specialized epithelial cells, synthesize and secrete surfactant. During the reparative process, these type II pneumocytes proliferate along the alveolar basement membranes, replacing damaged type I pneumocytes and reconstituting the alveolar lining. This proliferation of surfactant-secreting cells is an important step in the recovery of lung function after acute lung injury, such as in the case of Acute Respiratory Distress Syndrome (ARDS). | |||
52 | A 65-year-old male is treated for anal carcinoma with therapy including external beam radiation. How does radiation affect cancer cells? Options: (A): Induces the formation of thymidine dimers (B): Induces the formation of disulfide bonds (C): Induces G/T and A/C pair formation (D): Induces deamination of cytosine (E): Induces breaks in double-stranded DNA | Induces breaks in double-stranded DNA | Correct | The correct choice is (E) Induces breaks in double-stranded DNA. Explanation: Radiation therapy works by causing damage to the DNA of cancer cells. The key initial damage site is a DNA double-strand break. This double-strand break is repaired by various mechanisms, but it is repaired more slowly in tumor cells compared to normal tissues. Inducing breaks in double-stranded DNA can lead to cell death or mutations in the cancer cells, which can ultimately lead to their destruction. Therefore, option (E) is the correct choice. | |||
53 | A 56-year-old man with a history of hypertension presents to his physician with progressive fatigue and new onset muscle cramps. He has had no recent changes to his medication regimen, which includes hydrochlorothiazide, lisinopril, and amlodipine. His temperature is 98.0°F (36.7°C), blood pressure is 174/111 mmHg, pulse is 70/min, respirations are 12/min, and oxygen saturation is 98% on room air. The patient's cardiopulmonary and abdominal exams are unremarkable. Laboratory values are ordered as seen below. Serum: Na+: 138 mEq/L Cl-: 100 mEq/L K+: 3.3 mEq/L HCO3-: 33 mEq/L BUN: 20 mg/dL Glucose: 129 mg/dL What is the most likely underlying etiology of this patient's hypertension? Options: (A): Aldosterone excess (B): Catecholamine-secreting mass (C): Cortisol excess (D): Impaired kidney perfusion (E): Increased peripheral vascular resistance | Aldosterone excess | Correct | The correct choice is (A) Aldosterone excess. Explanation: The patient's hypertension, along with the laboratory values, suggests an underlying aldosterone excess. Aldosterone is a hormone produced by the adrenal glands that regulates sodium and potassium balance in the body. Excess aldosterone can lead to sodium retention and potassium loss, resulting in hypertension. In this case, the patient's low potassium level (K+: 3.3 mEq/L) is consistent with aldosterone excess. Additionally, the patient's fatigue and muscle cramps can be attributed to hypokalemia, which is commonly seen in aldosterone excess. The other options, such as catecholamine-secreting mass, cortisol excess, impaired kidney perfusion, and increased peripheral vascular resistance, are less likely based on the given information. | |||
54 | A 65-year-old man comes to the physician because of a 1-week history of yellowish discoloration of his skin and generalized pruritus. Examination shows jaundice of the skin and scleral icterus. Urinalysis shows an elevated concentration of bilirubin and a low concentration of urobilinogen. Which of the following is the most likely underlying cause of these findings? Options: (A): Absent UDP-glucuronosyltransferase activity (B): Increased hemoglobin breakdown (C): Increased intestinal bilirubin reabsorption (D): Defective hepatic bile excretion (E): Presence of stones within the gallbladder | Defective hepatic bile excretion | Correct | The correct choice is (D) Defective hepatic bile excretion. Explanation: The patient's presentation of yellowish discoloration of the skin and scleral icterus, along with elevated bilirubin levels in the urine, suggests a problem with bilirubin metabolism and excretion. Bilirubin is a breakdown product of hemoglobin and is normally conjugated in the liver with glucuronic acid by the enzyme UDP-glucuronosyltransferase. This conjugated bilirubin is then excreted into the bile and eventually eliminated in the feces as urobilinogen. In this case, the low concentration of urobilinogen in the urine suggests that there is a defect in the excretion of bilirubin into the bile. This is most likely due to a problem with hepatic bile excretion, as seen in conditions such as cholestasis or obstructive jaundice. These conditions can be caused by various factors, including liver disease, gallstones, or tumors obstructing the bile ducts. The other options are less likely to be the underlying cause in this case. Absent UDP-glucuronosyltransferase activity (option A) would result in unconjugated hyperbilirubinemia, not the conjugated hyperbilirubinemia seen in this patient. Increased hemoglobin breakdown (option B) would lead to increased unconjugated bilirubin levels, not conjugated bilirubin levels. Increased intestinal bilirubin reabsorption (option C) would result in increased urobilinogen levels in the urine, not low levels. The presence of stones within the gallbladder (option E) would not directly affect hepatic bile excretion. | |||
55 | A 72-year-old woman is brought to the physician by her daughter because of a 6-month history of worsening short-term memory deficits and social withdrawal. Treatment with galantamine is initiated. Two weeks later, the patient develops vomiting, mild crampy abdominal pain, and watery, nonbloody diarrhea. Which of the following is the most appropriate pharmacotherapy? Options: (A): Bethanechol (B): Metoclopramide (C): Loperamide (D): Atropine (E): Oxybutynin | Atropine | Correct | The correct choice is (D) Atropine. Explanation: The patient is experiencing gastrointestinal symptoms, including vomiting, abdominal pain, and diarrhea, which are common side effects of cholinesterase inhibitors like galantamine. These symptoms are due to increased cholinergic activity in the gastrointestinal tract. Atropine, an anticholinergic medication, can be used to counteract the cholinergic effects and relieve the gastrointestinal symptoms. Atropine blocks the action of acetylcholine at muscarinic receptors, reducing the excessive cholinergic stimulation in the gut. This helps to alleviate the symptoms of vomiting, abdominal pain, and diarrhea. Therefore, atropine is the most appropriate pharmacotherapy in this case. | |||
56 | A 61-year-old man with schizophrenia in a locked inpatient psychiatry unit was observed making an unusual smacking motion with his lips, pursing his mouth, and blinking excessively. These symptoms started slowly about 2 weeks ago and have become more pronounced, but they do not seem to bother the patient. He resides in an inpatient psychiatric facility where he has been successfully treated with haloperidol for the past several months. His physical exam and vitals are within normal limits. Which of the following accurately describes his symptoms? Options: (A): Akathisia (B): Tardive dyskinesia (C): Acute dystonia (D): Pseudoparkinsonism (E): Palsy | Tardive dyskinesia | Correct | The correct choice is (B) Tardive dyskinesia. Explanation: The patient's symptoms of making smacking motions with his lips, pursing his mouth, and excessive blinking are consistent with the characteristic symptoms of tardive dyskinesia. Tardive dyskinesia is an involuntary movement disorder that can occur as a side effect of long-term treatment with antipsychotic medications, such as haloperidol. It is characterized by abnormal, repetitive movements of the face, tongue, and extremities, including lip smacking, tongue thrusting, facial grimacing, and writhing movements of the arms or legs. These symptoms typically develop after prolonged exposure to antipsychotic medications and can persist even after the medication is discontinued. In this case, the patient's symptoms started slowly about 2 weeks ago and have become more pronounced, which is consistent with the development of tardive dyskinesia. It is important to monitor and manage tardive dyskinesia in patients receiving long-term antipsychotic treatment. | |||
57 | A 17-year-old football player with no significant past medical history, social history, or family history presents to his pediatrician with itching in his groin. He says this started during summer workouts leading up to this season. He denies having any rash anywhere else on his body. The blood pressure is 123/78 mm Hg, pulse is 67/min, respiratory rate is 15/min, and temperature is 38.1°C (98.7°F). Physical examination reveals an erythematous, well-demarcated patch with peripheral scale on the left thigh, pubic region, and perineum. There is no apparent scrotal involvement with the rash. How can you confirm the suspected diagnosis? Options: (A): Localized ultrasound (B): KOH examination of lesion scrapings (C): Nikolsky's sign on physical exam (D): Gram stain of skin scrapings (E): AFB stain of skin scrapings | KOH examination of lesion scrapings | Correct | The correct choice is (B) KOH examination of lesion scrapings. Explanation: The patient's presentation with itching in the groin, erythematous well-demarcated patch with peripheral scale, and absence of scrotal involvement is consistent with tinea cruris, also known as jock itch. Tinea cruris is a fungal infection caused by dermatophytes, commonly Trichophyton rubrum or Epidermophyton floccosum. To confirm the suspected diagnosis of tinea cruris, a KOH (potassium hydroxide) examination of lesion scrapings is the most appropriate test. This test involves obtaining a skin scraping from the affected area and mixing it with KOH solution. The KOH dissolves the keratin in the skin cells, allowing for visualization of fungal elements such as hyphae or spores under a microscope. The presence of these fungal elements confirms the diagnosis of tinea cruris. Localized ultrasound (A) is not necessary for the diagnosis of tinea cruris and would not provide any additional information. Nikolsky's sign (C) is a clinical sign seen in certain blistering skin conditions, such as pemphigus vulgaris, where slight rubbing of the skin causes separation of the epidermis. It is not relevant to the diagnosis of tinea cruris. Gram stain of skin scrapings (D) is used to identify bacteria, not fungi. Tinea cruris is caused by a fungal infection, so a Gram stain would not be helpful in confirming the diagnosis. AFB (acid-fast bacilli) stain of skin scrapings (E) is used to identify mycobacteria, specifically Mycobacterium tuberculosis. It is not relevant to the diagnosis of tinea cruris, which is caused by dermatophytes. | |||
58 | An otherwise healthy 26-year-old man comes to the physician for medication counseling after recently being diagnosed with schizophrenia. Risperidone therapy is initiated. This patient is at increased risk for which of the following adverse effects? Options: (A): Agranulocytosis (B): Shortened QT interval (C): Gynecomastia (D): Hypothyroidism (E): Weight loss | Gynecomastia | Correct | The correct choice is (C) Gynecomastia. Explanation: Risperidone therapy is associated with an increased risk of gynecomastia, which is the development of breast tissue in males. This is due to the medication's ability to increase prolactin levels, a hormone that stimulates breast development and milk production. Gynecomastia can cause breast tenderness and enlargement in males. It is important for healthcare providers to monitor for this adverse effect and address any concerns or discomfort that the patient may have. | |||
59 | A 15-year-old woman presents with fever, altered mental status and a petechial rash on her lower extremities and back since yesterday evening. She also says she has been nauseous for the past 3 hours and has vomited twice. The patient mentions she has had heavy menstrual bleeding for the past few days. Her blood pressure is 95/80 mm Hg and her temperature is 40.0°C (104.0°F). On physical examination, the patient appears diaphoretic. A pelvic examination reveals a tampon in her vagina. Binding and activation of which of the following T cell receptors is responsible for this patient’s most likely condition? Options: (A): B7 receptor (B): Variable β-sequence of the T cell receptor (C): CD40 (D): CD3 (E): IgCAM | Variable β-sequence of the T cell receptor | Correct | The correct choice is (B) Variable β-sequence of the T cell receptor. Explanation: This patient's presentation is consistent with toxic shock syndrome (TSS), which is most commonly caused by Staphylococcus aureus infection. TSS is characterized by fever, altered mental status, rash, hypotension, and multiorgan dysfunction. In this case, the patient's heavy menstrual bleeding and the presence of a tampon in her vagina provide a likely source of infection. T cells play a crucial role in the immune response against bacterial infections. The T cell receptor (TCR) is responsible for recognizing and binding to antigens presented by antigen-presenting cells (APCs). The TCR is composed of two chains, the α-chain and the β-chain, which are responsible for antigen recognition. The β-chain has a variable region that is responsible for binding to specific antigens. In this patient's case, the binding and activation of the variable β-sequence of the TCR would be responsible for the immune response against the Staphylococcus aureus infection causing toxic shock syndrome. The TCR would recognize and bind to antigens presented by APCs, leading to the activation of T cells and the subsequent immune response against the infection. Therefore, the correct answer is (B) Variable β-sequence of the T cell receptor. | |||
60 | A 2-year-old boy is brought to the physician for evaluation of pallor and increasing lethargy for 2 days. One week ago, he experienced abdominal pain, vomiting, and bloody diarrhea that have since subsided. The patient's father states that they returned early from a 6-week roadtrip in Mexico because of these symptoms. His parents have been giving him oral rehydration solution. His immunizations are up-to-date. He appears pale. His temperature is 38.4°C (101.1°F), pulse is 130/min, respirations are 35/min, and blood pressure is 95/50 mm Hg. Examination shows scleral icterus. The abdomen is soft and nontender; there is no rebound or guarding. Bowel sounds are hyperactive. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 8.5 g/dL Mean corpuscular volume 94 μm3 Leukocyte count 18,000/mm3 Platelet count 45,000/mm3 Prothrombin time 12 sec Partial thromboplastin time 34 sec Serum Urea nitrogen 28 mg/dL Creatinine 1.6 mg/dL Bilirubin Total 2.5 mg/dL Direct 0.1 mg/dL Lactate dehydrogenase 1658 U/L A blood smear shows schistocytes. Which of the following is the most likely diagnosis?" Options: (A): Henoch-Schönlein Purpura (B): Thrombotic thrombocytopenic purpura (C): Hemolytic uremic syndrome (D): Immune thrombocytopenic purpura (E): Disseminated intravascular coagulation " | Hemolytic uremic syndrome | Correct | The correct answer is (C) Hemolytic uremic syndrome. Hemolytic uremic syndrome (HUS) is a condition characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. It is most commonly caused by infection with Shiga toxin-producing Escherichia coli (STEC), particularly serotype O157:H7. In this case, the patient's symptoms of abdominal pain, vomiting, and bloody diarrhea one week prior are consistent with a gastrointestinal infection, which can be caused by STEC. The laboratory findings in this patient are also consistent with HUS. The presence of schistocytes on the blood smear indicates the presence of microangiopathic hemolytic anemia. The low platelet count and elevated lactate dehydrogenase (LDH) further support the diagnosis of HUS. Additionally, the patient's renal dysfunction, as evidenced by the elevated urea nitrogen and creatinine levels, is a common feature of HUS. The other answer choices can be ruled out based on the clinical presentation and laboratory findings. Henoch-Schönlein Purpura typically presents with palpable purpura, arthritis or arthralgia, abdominal pain, and renal involvement. Thrombotic thrombocytopenic purpura (TTP) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, fever, and renal dysfunction. Immune thrombocytopenic purpura (ITP) is characterized by isolated thrombocytopenia without evidence of hemolysis or renal dysfunction. Disseminated intravascular coagulation (DIC) is characterized by widespread activation of the coagulation cascade, leading to both bleeding and thrombosis. None of these conditions fully explain the patient's clinical presentation and laboratory findings. | |||
61 | A 17-year-old girl is referred by her dentist for a suspected eating disorder. She has been visiting the same dentist since childhood and for the past 2 years has had at least 2 visits for dental caries. She eventually admitted to him that she regularly induces vomiting by putting her fingers down her throat. She says she has been doing this for the last few years and purging at least once a week. More recently, she has been inducing emesis more often and even looked into diuretics as she feels that she is gaining more and more weight compared to her ‘skinny friends’. Her BMI is at the 50th percentile for her age and sex. Which of the following features is most consistent with this patient’s condition? Options: (A): Patients with this disorder are not further sub-typed (B): Patients do not usually initiate treatment (C): Patients can have a history of both anorexia and bulimia (D): Patients will typically have a BMI between 17–18.5 kg/m2 (E): Patients usually have significant medical complications | Patients with this disorder are not further sub-typed | Correct | The correct choice is (C): Patients can have a history of both anorexia and bulimia. Explanation: Based on the information provided, the patient regularly induces vomiting and purges at least once a week, which are characteristic behaviors of bulimia nervosa. However, she also expresses concerns about gaining weight and compares herself to her "skinny friends," which suggests body image distortion and fear of weight gain, characteristic of anorexia nervosa. This indicates that the patient may have a history of both anorexia and bulimia, making choice (C) the most consistent feature of her condition. Patients with eating disorders can present with a range of symptoms and behaviors, and it is not uncommon for individuals to have a history of multiple eating disorders. It is important to consider the possibility of co-occurring or transitioning eating disorders when evaluating patients with symptoms suggestive of an eating disorder. | |||
62 | A 14-year-old girl is brought to the physician by her father because of fever, chills, abdominal pain, and profuse non-bloody diarrhea. Her symptoms began one week ago, when she had several days of low-grade fever and constipation. She returned from Indonesia 2 weeks ago, where she spent the summer with her grandparents. Her temperature is 39.3°C (102.8°F). Examination shows diffuse abdominal tenderness and mild hepatosplenomegaly. There is a faint salmon-colored maculopapular rash on her trunk and abdomen. Which of the following is the most likely causal organism? Options: (A): Giardia lamblia (B): Schistosoma mansoni (C): Campylobacter jejuni (D): Salmonella typhi (E): Clostridium perfringens | Salmonella typhi | Correct | The correct answer is (D) Salmonella typhi. Explanation: The patient's symptoms of fever, chills, abdominal pain, and profuse non-bloody diarrhea, along with the history of travel to Indonesia, are suggestive of enteric fever, also known as typhoid fever. The most likely causal organism in this case is Salmonella typhi. Salmonella typhi is a gram-negative bacterium that causes typhoid fever. It is transmitted through the ingestion of contaminated food or water. Symptoms typically include fever, abdominal pain, and diarrhea. Hepatosplenomegaly and a faint salmon-colored maculopapular rash, known as rose spots, are characteristic findings in typhoid fever. Giardia lamblia (A) is a protozoan parasite that causes giardiasis, which is characterized by diarrhea, abdominal pain, and bloating. However, the symptoms and presentation described in the case are not consistent with giardiasis. Schistosoma mansoni (B) is a parasitic worm that causes schistosomiasis, a disease characterized by chronic infection of the liver, intestines, and urinary tract. The symptoms and presentation described in the case are not consistent with schistosomiasis. Campylobacter jejuni (C) is a bacterial pathogen that commonly causes gastroenteritis. While it can cause fever and diarrhea, the hepatosplenomegaly and rash described in the case are not typical of Campylobacter jejuni infection. Clostridium perfringens (E) is a bacterium that can cause food poisoning, but it typically presents with symptoms such as abdominal cramps and watery diarrhea. The symptoms and presentation described in the case are not consistent with Clostridium perfringens infection. | |||
63 | A 22-year-old female college student is treated with metronidazole after presenting to student health services with itching, discharge, and pain in her vagina. At a party shortly afterward she experiences facial flushing, nausea, tachycardia, dyspnea, headache, and abdominal cramps after consuming alcohol. Serum levels of which of the following are likely elevated in this patient following alcohol consumption: Options: (A): Acetaldehyde (B): Uric acid (C): Cytochrome P-450 enzymes (D): Triglycerides (E): Amylase | Acetaldehyde | Correct | The correct choice is (A) Acetaldehyde. Explanation: The patient is experiencing a disulfiram-like reaction after consuming alcohol following treatment with metronidazole. Metronidazole can interfere with alcohol metabolism and cause a buildup of acetaldehyde, leading to symptoms such as facial flushing, nausea, tachycardia, dyspnea, headache, and abdominal cramps. Acetaldehyde is the toxic metabolite of alcohol that is normally metabolized by the enzyme alcohol dehydrogenase. Inhibition of this enzyme by metronidazole leads to an accumulation of acetaldehyde, resulting in the disulfiram-like reaction. Therefore, serum levels of acetaldehyde are likely elevated in this patient following alcohol consumption. | |||
64 | A 23-year-old primigravida presents for a regular prenatal care visit at 16 weeks gestation. She complains of increased fatigability, but is otherwise well. She takes folic acid, iron, and vitamin D supplementation. Her vital signs are as follows: blood pressure, 110/70 mm Hg; heart rate, 86/min; respiratory rate, 13/min; and temperature, 36.6℃ (97.9℉). The physical examination is unremarkable. The complete blood count results are as below: Erythrocyte count 3.9 million/mm3 Hb 11.1 g/dL HCT 32% Reticulocyte count 0.2% MCV 90 fL Platelet count 210,000/mm3 Leukocyte count 8,100/mm3 Which of the following tests is required to investigate the cause of the patient’s laboratory findings? Options: (A): Serum iron level (B): Serum B12 level (C): Transferrin (D): No tests required (E): Total bilirubin | No tests required | Correct | The correct answer is (D) No tests required. Explanation: The patient's laboratory findings are consistent with mild iron deficiency anemia. The hemoglobin (Hb) level is slightly below the normal range (12-16 g/dL for women), and the hematocrit (HCT) is also slightly decreased. The mean corpuscular volume (MCV) is within the normal range (80-100 fL), indicating that the red blood cells are not abnormally small or large. The reticulocyte count is low, suggesting decreased production of red blood cells. The platelet count and leukocyte count are within the normal range. Given the patient's history of taking iron supplementation and the absence of any other abnormal findings on physical examination, it is likely that the mild iron deficiency anemia is due to inadequate iron intake or absorption rather than a more serious underlying cause. Therefore, no further tests are required at this time. The patient should be advised to continue taking her iron supplementation and to consume iron-rich foods to improve her iron levels. Regular follow-up and monitoring of her hemoglobin levels should be done to ensure improvement. | |||
65 | An 80-year-old man is transferred from a step-down unit to a med-surg floor in the hospital. He had undergone a successful hernia surgery 14 hours ago. Before the surgery, he was pre-treated with atropine, scopolamine, and morphine and recovered well in the PACU after the surgery. There were no complications in the step-down unit and the patient continued to recover. On the med-surg floor, his temperature is 36.8°C (98.2°F), the heart rate is 98/min, the respiratory rate is 15/min, the blood pressure is 100/75 mm Hg, the oxygen saturation is 90%. On physical exam, he is a well-developed, obese man. His heart has a regular rate and rhythm and his lungs are clear to auscultation bilaterally. His incision site is clean, dry, and intact with an appropriate level of swelling and erythema. During the physical, the patient mentions some discomfort in his abdomen and pelvis and during a records review it is noted that he has not passed urine in the PACU, step-down unit, or since arriving on the med-surg floor. A bladder scan is inconclusive due to body habitus. What is the next best step in the treatment of this patient? Options: (A): Insert a ‘straight cath’ into the patient’s bladder (B): Ultrasound the surgical site (C): Aggressive IV fluids (D): Digital rectal exam (E): Renal ultrasound | Insert a ‘straight cath’ into the patient’s bladder | Correct | The correct answer is (A): Insert a ‘straight cath’ into the patient’s bladder. Explanation: The patient's inability to pass urine since the surgery, along with the discomfort in the abdomen and pelvis, suggests urinary retention. This can be a common complication after surgery, especially in elderly patients. The patient's inability to pass urine can be due to the effects of anesthesia, medications such as opioids, or postoperative pain. In this case, a bladder scan was inconclusive due to the patient's body habitus, so the next best step would be to insert a 'straight catheter' into the patient's bladder. This will help relieve the urinary retention and allow for the measurement of urine output. It will also help assess for any potential complications such as bladder distention or urinary tract infection. Ultrasound of the surgical site (option B) may be indicated if there are concerns about wound healing or infection, but it does not address the patient's urinary retention. Aggressive IV fluids (option C) may be indicated in certain situations, such as hypovolemia or dehydration, but it does not address the patient's urinary retention. A digital rectal exam (option D) may be useful in assessing for any rectal or pelvic abnormalities, but it does not address the patient's urinary retention. A renal ultrasound (option E) may be indicated if there are concerns about renal function or urinary tract obstruction, but it does not address the immediate issue of urinary retention. | |||
66 | A healthy 19-year-old man presents to his primary care provider complaining of painless “blisters” in his mouth. He reports that he noticed a white film on his tongue and the sides of his mouth 2 days ago while brushing his teeth. The film was easily brushed off. He also complains of a bitter metallic taste in his mouth but otherwise denies pain, burning, dysphagia, or hoarseness. He is otherwise healthy and takes no medications. He is a competitive swimmer and has had 8 sexual partners in the past year. He intermittently uses barrier protection. On exam, he is well-appearing and in no acute distress. His oral examination demonstrates patches of white pseudomembranes that can be wiped away to reveal erythematous mucosa. A medication with which of the following mechanisms of action is most appropriate in this patient? Options: (A): Disruption of cell membrane permeability (B): Disruption of microtubule formation (C): Inhibition of 14-alpha-demethylase (D): Inhibition of beta-glucan synthase (E): Inhibition of squalene epoxidase | Disruption of cell membrane permeability | Correct | The correct answer is (A): Disruption of cell membrane permeability. Explanation: The patient's presentation is consistent with oral candidiasis, which is caused by an overgrowth of Candida species in the mouth. The white pseudomembranes that can be wiped away to reveal erythematous mucosa are characteristic of this condition. Candida species have a cell wall composed of a phospholipid bilayer, and disruption of the cell membrane permeability is the most appropriate mechanism of action for treating this infection. Option (B): Disruption of microtubule formation is not the correct answer because this mechanism of action is associated with drugs used to treat fungal infections caused by dermatophytes, such as griseofulvin. Option (C): Inhibition of 14-alpha-demethylase is not the correct answer because this mechanism of action is associated with azole antifungal drugs, which are used to treat systemic fungal infections, such as candidemia or invasive aspergillosis. Option (D): Inhibition of beta-glucan synthase is not the correct answer because this mechanism of action is associated with echinocandin antifungal drugs, which are used to treat invasive fungal infections, such as candidemia or invasive aspergillosis. Option (E): Inhibition of squalene epoxidase is not the correct answer because this mechanism of action is associated with allylamine antifungal drugs, which are used to treat dermatophyte infections, such as tinea corporis or tinea pedis. | |||
67 | A 56-year-old man presents to the clinic complaining of subacute back pain for the past month. The pain is described as a dull, constant ache that is worse at night. He could not recall any precipitating event except for an amateur weight-lifting competition that he participated in 2 months ago. Past medical history is significant for non-small cell lung cancer that was diagnosed and successfully treated. A PET scan 1 year ago demonstrated no recurrence. Physical exam was unremarkable except for some point tenderness along the lumbosacral area. What is the most likely imaging finding in this patient? Options: (A): Blastic lesions of the lumbar spine (B): Bulging disc impinging on lumbar spinal nerve (C): Lytic lesions of the lumbar spine (D): Narrowing of the lumbar disc space (E): Sacroilitis and fusion of the lumbar spine | Lytic lesions of the lumbar spine | Correct | The correct answer is (C): Lytic lesions of the lumbar spine. Explanation: Given the patient's history of non-small cell lung cancer and the presence of persistent, severe back pain, the most likely imaging finding in this patient would be lytic lesions of the lumbar spine. Lytic lesions refer to areas of bone destruction, which can be caused by metastatic cancer. In patients with a history of cancer, back pain that worsens at night and is not relieved by rest should raise suspicion for metastatic disease. The point tenderness along the lumbosacral area further supports the possibility of lytic lesions in the lumbar spine. Blastic lesions (option A) refer to areas of increased bone density and are less likely in this patient with a history of lung cancer. Bulging disc impinging on lumbar spinal nerve (option B) and narrowing of the lumbar disc space (option D) are more commonly associated with degenerative disc disease and would not explain the patient's symptoms and history. Sacroilitis and fusion of the lumbar spine (option E) are less likely given the absence of specific findings on physical examination and the patient's history of lung cancer. | |||
68 | A 4-year-old boy is brought to the emergency department because of severe abdominal pain and bilious vomiting for 6 hours. He has not had bowel movements in the past 24 hours. He appears ill. His temperature is 37.8°C (100°F) and pulse is 122/min. Examination shows a distended abdomen. There is tenderness to palpation in the lower abdomen; guarding and rebound tenderness are present. Bowel sounds are decreased. An x-ray of the abdomen shows dilated loops of bowel. He has been accompanied by his 14-year-old brother. The surgeon recommends an emergency laparotomy. The parents are away visiting friends and cannot be reached. Which of the following is the most appropriate next best step in management? Options: (A): Get consent from the patient's brother (B): Get consent from the patient (C): Obtain a court order for surgery (D): Perform emergency laparotomy (E): Delay surgery until parental consent | Perform emergency laparotomy | Correct | The correct choice is (D) Perform emergency laparotomy. Explanation: In this scenario, the 4-year-old boy presents with severe abdominal pain, bilious vomiting, distended abdomen, tenderness to palpation, guarding, rebound tenderness, and decreased bowel sounds. These findings, along with the x-ray showing dilated loops of bowel, are consistent with a surgical emergency, such as intestinal obstruction or volvulus. Delaying surgery could lead to further complications and potentially life-threatening consequences for the patient. In emergency situations where the parents or legal guardians cannot be reached, the principle of "implied consent" can be applied. Implied consent means that in life-threatening situations where immediate intervention is necessary, healthcare providers can proceed with treatment without explicit consent from the patient or their legal guardians. The surgeon's recommendation for an emergency laparotomy indicates the urgency of the situation, and waiting for parental consent or obtaining a court order would cause unnecessary delays in providing the necessary medical care. While it is important to involve the patient's family and obtain consent as soon as possible, the priority in this case is to address the immediate medical needs of the patient. Therefore, the most appropriate next best step in management is to perform the emergency laparotomy. | |||
69 | A 3-week-old male newborn is brought to the hospital because of poor weight gain since birth. He was born at 38 weeks' gestation via normal vaginal delivery. He weighed 3005 g (6 lb, 10 oz) at birth and currently weighs 2835 g (6 lb, 4 oz). He has been latching on and breastfeeding well since birth. His mother has a history of Graves' disease and underwent near-total thyroidectomy in the second trimester of her pregnancy after her symptoms could not be controlled with antithyroid drugs. She is currently receiving L-thyroxine therapy. The patient's temperature is 38.9°C (102°F), pulse is 176/min, and respirations are 42/min. He appears irritable. Examination shows a diaphoretic infant with a paucity of subcutaneous fat. There is swelling of the neck at the midline. Which of the following is the most likely cause? Options: (A): Transplacental passage of thyroglobulin antibodies (B): Transplacental passage of thyroid peroxidase antibodies (C): Transplacental passage of TSH receptor antibodies (D): Transplacental viral infection (E): Opiate use in the mother | Transplacental passage of TSH receptor antibodies | Correct | The correct choice is (C): Transplacental passage of TSH receptor antibodies. Explanation: In this case, the newborn's mother has a history of Graves' disease, which is an autoimmune disorder characterized by the production of antibodies against the thyroid gland. These antibodies can cross the placenta and stimulate the baby's thyroid gland, leading to neonatal hyperthyroidism. The symptoms of poor weight gain, irritability, and swelling of the neck are consistent with hyperthyroidism. The presence of TSH receptor antibodies in both the mother and the baby confirms the diagnosis. Treatment is necessary to manage the severe metabolic stress the infant is experiencing. | |||
70 | A 57-year-old female with a past medical history of alcoholism presents to the emergency room vomiting bright red blood. She is accompanied by her partner, who reports that she had been complaining of black and tarry stools for the past several days. Vital signs are temperature 37 degrees celsius, heart rate 141 beats per minute, blood pressure 90/60, respiratory rate 20, and oxygen saturation 99% on room air. On physical examination, she has splenomegaly and a positive fluid wave. The remainder of her examination is within normal limits. The patient is stabilized with intravenous fluids, and her blood pressure improves. Subsequent emergent upper endoscopy reveals bleeding from the submucosal veins in the lower 1/3 of the esophagus, but no gastric bleed. In the endoscopy suite she also receives IV octreotide. After intervention and resolution of her acute bleed, which of the following pharmacologic agents is indicated? Options: (A): Phentolamine (B): Prazosin (C): Nifedipine (D): Nadalol (E): Doxazosin | Nadalol | Correct | The correct answer is (D) Nadalol. Explanation: In this scenario, the patient presents with bleeding from the submucosal veins in the lower 1/3 of the esophagus, which is suggestive of esophageal varices. Esophageal varices are dilated submucosal veins that occur as a result of portal hypertension, often seen in patients with chronic liver disease, such as alcoholism. The initial management of acute variceal bleeding includes volume resuscitation with intravenous fluids to stabilize the patient's hemodynamic status. In addition to volume resuscitation, pharmacologic therapy is indicated to reduce portal pressure and prevent rebleeding. The medication of choice for acute variceal bleeding is a nonselective beta-blocker, such as nadolol or propranolol. These medications reduce portal pressure by decreasing splanchnic blood flow and cardiac output. They have been shown to decrease the risk of rebleeding and improve survival in patients with acute variceal bleeding. Octreotide, which the patient received during the endoscopy, is also used in the treatment of variceal bleeding, but it is not recommended for routine use in patients with acute nonvariceal upper GI bleeding. Phentolamine (A), prazosin (B), nifedipine (C), and doxazosin (E) are not indicated in the management of acute variceal bleeding. Phentolamine is an alpha-blocker used for the treatment of hypertensive emergencies. Prazosin, nifedipine, and doxazosin are not recommended for the management of acute variceal bleeding. | |||
71 | A 65-year-old man with a history of hypertension, obesity, and alcoholic cirrhosis is seen in clinic for follow-up. He feels well and currently drinks 5 glasses of wine each night. Medications include atenolol and lisinopril. On physical exam, temperature is 98.1 deg F (36.7 deg C), blood pressure is 151/82 mmHg, pulse is 71/min, and respirations are 14/min. He has spider angiomata on his chest; no asterixis, jaundice, ascites, or peripheral edema is noted. Screening ultrasound reveals a new liver nodule, and follow up CT demonstrates a 2 cm right hepatic lobe lesion with enhancement in the arterial phase. No hypodense attenuation is seen on the venous or delayed phase. What is the next step in management? Options: (A): Proceed with liver biopsy (B): Refer for surgical resection (C): Refer for radiofrequency ablation (D): Treat with sorafenib (E): Observe and get follow-up imaging in 3 months | Proceed with liver biopsy | Correct | The correct answer is (A) Proceed with liver biopsy. Explanation: In this case, the patient has a history of alcoholic cirrhosis and a new liver nodule on imaging. The presence of a liver nodule in a patient with cirrhosis raises concern for hepatocellular carcinoma (HCC), which is the most common primary liver malignancy. The next step in management is to proceed with a liver biopsy to confirm the diagnosis of HCC. Liver biopsy is the gold standard for diagnosing HCC and can provide important information about the tumor's histology, grade, and stage. It can also help determine the appropriate treatment approach. In this case, a liver biopsy will help confirm the diagnosis of HCC and guide further management decisions. The other options are not the most appropriate next steps in management for this patient: - (B) Surgical resection is not the first-line treatment for HCC, especially in patients with cirrhosis. Surgical resection is typically reserved for patients with early-stage HCC and preserved liver function. - (C) Radiofrequency ablation is a treatment option for early-stage HCC, but it should not be the first step in management. The diagnosis of HCC should be confirmed before considering ablative therapies. - (D) Sorafenib is a systemic therapy used for advanced-stage HCC, but it is not the first-line treatment for patients with a new liver nodule. The diagnosis should be confirmed before initiating systemic therapy. - (E) Observing and getting follow-up imaging in 3 months is not the most appropriate next step. Given the patient's history of cirrhosis and the presence of a liver nodule, prompt evaluation and diagnosis are necessary to guide appropriate management. | |||
72 | A 66-year-old man is brought to the emergency room by his wife due to abdominal distension and persistent somnolence for the past 2 weeks. The patient’s wife says that he has been sleeping much more than usual for the past 5 days. His bowel and bladder habit have not changed. His past medical history is significant for alcoholic liver cirrhosis. His vital signs include: pulse 76/min, respiratory rate 15/min, temperature 38.0°C (100.4°F) and blood pressure 122/75 mm Hg. On physical examination, the patient is altered and not responsive to commands. Oriented x 0. The abdomen is significantly distended. Shifting dullness is present and a positive fluid wave can be elicited. Hyperreflexia and asterixis are noted. Laboratory findings are significant for the following: Laboratory test Sodium 140 mEq/L Potassium 3.5 mEq/L Chloride 97 mEq/L Glucose 90 mg/dL Ammonia 100 µg/dL (ref: 19-60 µg/dL) Arterial blood gas pH 7.4 pCO2 40 mm Hg pO2 90 mm Hg HCO3 26 mEq/L An abdominal ultrasound shows surface nodularity compatible with cirrhosis but no other changes aside from ascites. An upper GI endoscopy is performed which shows gastric varices with no signs of active bleeding. An MRI of the brain is insignificant. What is the most likely precipitating factor that led to this patient’s condition? Options: (A): Spontaneous bacterial peritonitis (B): Metabolic alkalosis (C): Variceal gastrointestinal bleeding (D): Portal vein thrombosis (E): Hypoglycemia | Spontaneous bacterial peritonitis | Correct | The correct answer is (A) Spontaneous bacterial peritonitis. Explanation: The patient in this case has signs and symptoms consistent with hepatic encephalopathy, which is a neuropsychiatric syndrome that occurs in patients with liver dysfunction. The most common precipitating factor for hepatic encephalopathy in patients with cirrhosis is an infection, particularly spontaneous bacterial peritonitis (SBP). SBP is an infection of the ascitic fluid without an evident intra-abdominal source. It is characterized by fever, abdominal pain, and altered mental status. In this case, the patient has abdominal distension, altered mental status, and laboratory findings consistent with SBP (elevated ammonia level). The presence of ascites on abdominal ultrasound further supports the diagnosis of SBP. Other precipitating factors for hepatic encephalopathy include gastrointestinal bleeding, constipation, electrolyte abnormalities, and medications. However, in this case, there are no signs of active bleeding on upper GI endoscopy and the patient's electrolyte levels are within normal limits. Therefore, the most likely precipitating factor in this patient is SBP. | |||
73 | A 27-year-old man presents to the emergency department after a motor vehicle collision. The patient was the front seat unrestrained driver in a head on collision. The patient’s echocardiogram (ECG) is notable only for sinus tachycardia. His temperature is 99.5°F (37.5°C), blood pressure is 107/58 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. The patient is given 2 liters of Ringer lactate solution and morphine. Initial workup demonstrates that the patient’s pulmonary capillary wedge pressure and troponins are elevated. The patient is currently complaining of chest pain. Physical exam is notable for an uncomfortable young man with bruising over his chest wall. Which of the following is the most likely diagnosis? Options: (A): Cardiac contusion (B): Hemorrhage (C): Myocardial infarction (D): Pulmonary contusion (E): Takotsubo cardiomyopathy | Cardiac contusion | Correct | The correct answer is (A) Cardiac contusion. Explanation: In this scenario, the patient was involved in a motor vehicle collision and presents with chest pain, elevated troponins, and bruising over the chest wall. These findings are consistent with a cardiac contusion. Cardiac contusion refers to blunt injury to the heart muscle, typically caused by a direct impact to the chest. It can occur in high-speed motor vehicle collisions, falls from a height, or other traumatic events. The force of the impact can cause compression of the heart against the sternum, leading to injury. The clinical presentation of a cardiac contusion can vary widely. Patients may complain of chest pain, which can be similar to that seen in myocardial infarction. ECG findings may be nonspecific, as seen in this patient with sinus tachycardia. Elevated troponin levels can also be seen, indicating myocardial injury. Physical examination findings may include bruising over the chest wall, as seen in this patient. Other signs may include signs of cardiac dysfunction such as hypotension, tachycardia, or signs of heart failure. It is important to note that other conditions such as myocardial infarction, pulmonary contusion, and Takotsubo cardiomyopathy can also present with chest pain and elevated troponins. However, the presence of bruising over the chest wall in this patient, along with the mechanism of injury, makes cardiac contusion the most likely diagnosis. | |||
74 | A 56-year-old man presents to the emergency department for progressively worsening fatigue, malaise, fever, and abdominal pain. He reports that his symptoms began approximately 1 week ago and he has noticed episodes of diarrhea. He recently started melatonin and magnesium supplementation in hopes of improving his sleep. Medical history is significant for alcohol use disorder that required multiple hospital admissions for management of acute pancreatitis and cirrhosis. He states that he occasionally injects heroin intravenously. Temperature is 100°F (37.8°C), blood pressure is 105/70 mmHg, pulse is 92/min, and respirations are 17/min. Physical examination is significant for scleral icterus, hepatomegaly, ascites, and diffuse abdominal tenderness. Laboratory testing is significant for leukocytosis and metabolic acidosis. A paracentesis is performed and he is admitted into the hospital to receive intravenous cefotaxime and albumin. Ascitic fluid analysis demonstrates a polymorphonuclear cell count of 280 cells/mm^3, serum-ascites albumin gradient of 1.3 g/dL, and a culture positive for Escherichia coli sensitive to cefotaxime and ceftriaxone. On hospital day 2, the nurse reports that the patient is oliguric in the setting of constant fluid intake. Physical examination is unchanged. Laboratory testing is significant for a serum sodium of 131 mEq/L and creatinine of 1.8 mg/dL (it was 0.9 mg/dL on admission). Urine studies are significant for a low urine sodium level, without evidence of blood or protein. Since the hospital admission, he has not been started on any new medications. Which of the following will be the best treatment option for this patient? Options: (A): Adding dopamine to his treatment regimen (B): Adding lisinopril to his treatment regimen (C): Liver transplantation (D): Switching cefotaxime to ceftriaxone (E): Transjugular intrahepatic portosystemic shunting | Liver transplantation | Correct | The correct answer is (C) Liver transplantation. Explanation: This patient presents with signs and symptoms of hepatorenal syndrome (HRS), which is a potentially reversible functional renal failure that occurs in patients with advanced liver disease. HRS is characterized by a rapid decline in renal function, oliguria, and low urine sodium concentration (<10 mEq/L) in the absence of other causes of renal dysfunction. The diagnosis of HRS is based on clinical criteria and exclusion of other causes of renal dysfunction. In this patient, the low urine sodium concentration and absence of blood or protein in the urine support the diagnosis of HRS. The treatment of choice for HRS is liver transplantation, as it addresses the underlying cause of the renal dysfunction. Other treatment options, such as adding dopamine or lisinopril to the treatment regimen, switching antibiotics, or performing a transjugular intrahepatic portosystemic shunt, do not address the underlying liver disease and are not effective in treating HRS. | |||
75 | A 29-year-old woman presents to the clinic after several months of weight loss. She noticed a 6.8 kg (15 lb) unintentional weight loss over the preceding several months. She has not changed her diet or exercise habits. She also reports feuding with her boyfriend over the temperature of their shared apartment, as she always feels warmer than he does. The vital signs include: heart rate 110/min and blood pressure 146/78 mm Hg. The physical exam is notable for warm and slightly moist skin. She also exhibits a fine tremor in her hands when her arms are outstretched. The urine pregnancy test is negative. Which of the following is the best single treatment option for this patient? Options: (A): Glucocorticoids (B): Methimazole (C): Propranolol (D): Radioiodine therapy (E): Thyroidectomy | Methimazole | Correct | The correct choice is (B) Methimazole. Explanation: Based on the patient's symptoms and physical exam findings, she is most likely experiencing symptoms of hyperthyroidism. The weight loss, feeling warmer than others, increased heart rate, and fine tremor are all consistent with hyperthyroidism. Methimazole is a medication that is commonly used to treat hyperthyroidism. It works by inhibiting the production of thyroid hormones, which helps to normalize the thyroid function and alleviate the symptoms of hyperthyroidism. Glucocorticoids (choice A) are not the best treatment option for this patient because they are used to treat conditions such as adrenal insufficiency or autoimmune diseases, not hyperthyroidism. Propranolol (choice C) is a beta-blocker that can help control the symptoms of hyperthyroidism, such as rapid heart rate and tremors. However, it does not address the underlying cause of hyperthyroidism and is not considered the best single treatment option. Radioiodine therapy (choice D) and thyroidectomy (choice E) are both options for definitive treatment of hyperthyroidism, but they are typically reserved for patients who do not respond to or cannot tolerate antithyroid medications like methimazole. These options are more invasive and have potential long-term consequences, so they are not the best initial treatment choice for this patient. | |||
76 | A 21-year-old man comes to the physician because of pruritus and a hypopigmented rash on his upper body for 5 days. He first noticed the symptoms after returning from a business trip last week in the Bahamas. While he was there, he visited a couple of beaches and went hiking with some coworkers. The rash initially started as a single lesion on his upper back but since then has extended to his shoulders. He has a history of type 1 diabetes mellitus controlled with an insulin pump. He works as an office manager and has no known exposure to melanocytotoxic chemicals. He has been sexually active with three female partners over the past year and uses condoms inconsistently. He is 183 cm (6 ft) tall and weighs 80 kg (176 lb); BMI is 23.9 kg/m2. His temperature is 37.2°C (99°F), pulse is 78/min, and blood pressure is 130/84 mm Hg. A photograph of the rash is shown. One month ago, his hemoglobin A1C was 7.8%. Which of the following is most likely to confirm the diagnosis? Options: (A): Wood lamp examination (B): Skin culture (C): Potassium hydroxide preparation (D): Skin biopsy (E): Antinuclear antibody testing " | Potassium hydroxide preparation | Correct | The correct choice is (C) Potassium hydroxide preparation. Explanation: Based on the patient's history and presentation, the most likely diagnosis is tinea versicolor, a superficial fungal infection caused by Malassezia species. The hypopigmented rash, pruritus, and recent travel to a tropical location are consistent with this diagnosis. Tinea versicolor is commonly seen in individuals with oily skin, excessive sweating, and immunosuppression, such as in patients with diabetes mellitus. The diagnosis of tinea versicolor is confirmed by performing a potassium hydroxide (KOH) preparation of skin scrapings from the affected area. The KOH preparation allows for visualization of the characteristic "spaghetti and meatballs" appearance, which represents the hyphae and spores of the fungus. Other diagnostic modalities, such as dermoscopy, wood lamp examination, skin culture, skin biopsy, and antinuclear antibody testing, are not necessary for the diagnosis of tinea versicolor. | |||
77 | A 5-year-old female is brought to a speech therapist for continuing work on improving her communication skills. She is only able to verbalize two word sentences and has generalized developmental delay. When she was born it was noticed that she had a high pitched mewing cry and subsequent physical exam revealed microcephaly, prominent epicanthal folds, and a holosystolic murmur best heard in the left 5th intercostal space near the sternum. An abnormality of which of the following chromosomes is most likely responsible for this patient's disorder? Options: (A): 5 (B): 7 (C): 13 (D): 18 (E): 21 | 5 | Correct | The correct choice is (A) 5. Explanation: The patient's clinical presentation is consistent with Cri-du-chat syndrome, which is caused by a deletion of the short arm of chromosome 5 (5p-). This syndrome is characterized by a high-pitched mewing cry in infancy, microcephaly, developmental delay, and distinctive facial features such as prominent epicanthal folds. The holosystolic murmur heard in the left 5th intercostal space near the sternum is likely due to a congenital heart defect, which is commonly associated with this syndrome. Therefore, the abnormality of chromosome 5 is most likely responsible for this patient's disorder. | |||
78 | A 62-year old female comes to the physician because of vaginal spotting and urinary urgency for the past 4 days. She has had no fever, abdominal pain, or diarrhea. Menopause occurred at 52 years of age. Her last Pap smear 1 year ago was normal. She has hypertension, hypercholesterolemia, and diabetes. Medications include atorvastatin, hydrochlorothiazide, metformin, and aspirin. She is sexually active with her husband. Her temperature is 37°C (98.6°F), pulse is 95/min, respirations are 12/min, and blood pressure is 155/65 mm Hg. Pelvic exam demonstrates a 4 x 3 cm firm, immobile erythematous mass on the right inner vaginal wall. Which of the following is the most appropriate next step in management? Options: (A): Pap smear (B): Biopsy of the mass (C): Loop electrosurgical excision procedure (D): Incision and drainage (E): Urine gonorrhea and chlamydia testing | Biopsy of the mass | Correct | The correct choice is (B) Biopsy of the mass. Explanation: Given the patient's age, postmenopausal status, and the presence of a firm, immobile erythematous mass on the vaginal wall, the most appropriate next step in management is to perform a biopsy of the mass. This is because the patient's symptoms and physical examination findings are concerning for a possible malignancy, such as vaginal cancer. Biopsy of the mass will allow for histopathological examination to determine the nature of the mass and guide further management. A Pap smear (choice A) is not the most appropriate next step in management because it is a screening test for cervical cancer and may not provide sufficient information about the nature of the vaginal mass. A loop electrosurgical excision procedure (choice C) is a surgical procedure used for the treatment of cervical dysplasia and is not indicated in this patient with a vaginal mass. Incision and drainage (choice D) is not indicated in this patient as there is no evidence of an abscess or infection. Urine gonorrhea and chlamydia testing (choice E) is not indicated in this patient as her symptoms and physical examination findings are not consistent with a genitourinary infection. | |||
79 | A 59-year-old man is evaluated for progressive joint pain. There is swelling and tenderness over the first, second, and third metacarpophalangeal joints of both hands. His hand radiograph is shown. He has had diabetes mellitus for 2 years which is not well controlled with medications. Lab studies show a transferrin saturation of 88% and serum ferritin of 1,200 ng/mL. Which of the following best represents the etiology of this patient condition? Options: (A): Deposition of urate crystals (B): Deposition of calcium pyrophosphate (CPP) crystals (C): Degenerative joint disorder (D): Inflammatory rheumatological syndrome (E): Pathogenic inoculation of microbes | Deposition of calcium pyrophosphate (CPP) crystals | Correct | The correct choice is (B) Deposition of calcium pyrophosphate (CPP) crystals. Explanation: The patient's presentation of joint pain, swelling, and tenderness over the metacarpophalangeal joints, along with the radiographic findings of beak-like osteophytes, subchondral cysts, and osteopenia, are consistent with calcium pyrophosphate crystal deposition (CPPD) disease. CPPD disease is characterized by the deposition of calcium pyrophosphate crystals in the joints, leading to inflammation and joint damage. The presence of diabetes mellitus and poorly controlled blood sugar levels may contribute to the development of CPPD disease. Diabetes is a risk factor for the development of crystal deposition diseases, including CPPD disease. Elevated levels of serum ferritin and transferrin saturation may also be seen in patients with CPPD disease, as iron overload can contribute to crystal formation. Deposition of urate crystals (option A) is seen in gout, which typically presents with acute episodes of joint pain, redness, and swelling. This patient's presentation is more consistent with a chronic, progressive joint disorder. Degenerative joint disorder (option C) refers to osteoarthritis, which is characterized by joint degeneration and cartilage loss. While this patient may have some features of osteoarthritis on radiographic imaging, the presence of beak-like osteophytes and subchondral cysts is more suggestive of CPPD disease. Inflammatory rheumatological syndrome (option D) is a broad term that can encompass various autoimmune and inflammatory conditions, such as rheumatoid arthritis or systemic lupus erythematosus. However, the patient's presentation and radiographic findings are not consistent with these conditions. Pathogenic inoculation of microbes (option E) would suggest an infectious etiology, such as septic arthritis. However, there is no mention of signs of infection, such as fever or systemic symptoms, and the radiographic findings are not consistent with septic arthritis. | |||
80 | A newborn is found to be extremely cyanotic immediately after birth. He then develops progressive respiratory failure and is admitted to the neonatal ICU. A single loud S2 heart sound is appreciated as well as a machine-like murmur at the left upper sternal border. Radiography shows an enlarged "egg-shaped" heart. The newborn is then taken for a atrial septostomy to alleviate the condition pending definitive surgical correction. Which of the following is the most likely cause of this newborn's condition? Options: (A): Coarctation of the aorta (B): Persistent truncus arteriosus (C): Tetralogy of Fallot (D): Transposition of great vessels (E): Tricuspid atresia | Transposition of great vessels | Correct | The correct answer is (D) Transposition of great vessels. Explanation: The clinical presentation of this newborn, including extreme cyanosis immediately after birth, progressive respiratory failure, a single loud S2 heart sound, and a machine-like murmur at the left upper sternal border, is consistent with transposition of the great vessels. Transposition of the great vessels is a congenital heart defect in which the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle, resulting in a complete separation of the systemic and pulmonary circulations. This leads to cyanosis and respiratory distress shortly after birth. The enlarged "egg-shaped" heart seen on radiography is a characteristic finding in transposition of the great vessels. This is due to the abnormal positioning of the great vessels, resulting in an abnormal cardiac silhouette. Atrial septostomy is a procedure performed to alleviate the condition temporarily by creating an atrial communication, allowing for mixing of oxygenated and deoxygenated blood. This is done as a bridge to definitive surgical correction. Coarctation of the aorta (option A) is unlikely in this case as it typically presents with differential pulses and not with cyanosis and respiratory failure. Persistent truncus arteriosus (option B) is also unlikely as it presents with a loud single S2 heart sound and a harsh systolic ejection murmur at the upper left sternal border, but not with cyanosis and respiratory failure. Tetralogy of Fallot (option C) is the most common form of cyanotic heart disease, but the obstruction at the pulmonary valve is often not severe enough to result in cyanosis in the newborn. Additionally, the characteristic findings of tetralogy of Fallot, such as a boot-shaped heart on radiography and right ventricular hypertrophy on ECG, are not mentioned in the clinical presentation. Tricuspid atresia (option E) is unlikely as it typically presents with cyanosis and respiratory distress shortly after birth, but the clinical findings described in the question stem, such as a single loud S2 heart sound and a machine-like murmur, are not consistent with tricuspid atresia. | |||
81 | A 25-year-old male involved in a knife fight presents with a penetrating wound to the chest. The patient is unconscious and cannot provide any further history. Vitals show a temperature of 37-0°C (98.6°F), blood pressure of 85/55 mm Hg, pulse of 115/min, respirations of 19/min, and oxygen saturation of 92% on room air. On physical examination, the patient is diaphoretic and unresponsive. Extremities are pale and cool. There is a 3-inch long penetrating wound between the 3rd and 4th intercostal space on the left side of the chest, which is bleeding profusely. Transthoracic echocardiography reveals a full thickness penetrating injury to the right ventricular free wall. There are no apparent injuries to any coronary arteries or major branches. The patient is intubated and aggressive fluid resuscitation is initiated, including a blood transfusion. Which of the following is the best definitive surgical approach to take in this patient? Options: (A): Immediate cardiac transplant (B): Watchful waiting while resuscitative fluids are initiated (C): Interrupted 2-0 polypropylene suture with supporting pledgets (D): Needle thoracostomy over the 2nd intercostal space (E): Surgical adhesive glue | Interrupted 2-0 polypropylene suture with supporting pledgets | Correct | The correct choice is (C) Interrupted 2-0 polypropylene suture with supporting pledgets. Explanation: In this scenario, the patient has a penetrating wound to the chest with profuse bleeding and a full thickness penetrating injury to the right ventricular free wall. The patient is hemodynamically unstable with hypotension, tachycardia, and signs of poor perfusion. The best definitive surgical approach in this patient is to perform an interrupted 2-0 polypropylene suture with supporting pledgets. The goal of surgical management in this case is to control the bleeding and repair the cardiac injury. Interrupted sutures with supporting pledgets are commonly used to repair penetrating cardiac injuries. The sutures provide hemostasis and closure of the defect, while the pledgets provide additional support and prevent suture pull-through. Immediate cardiac transplant (A) is not indicated in this patient as it is a highly invasive procedure and is not necessary for the management of a penetrating cardiac injury. Watchful waiting while resuscitative fluids are initiated (B) is not appropriate in this case as the patient is hemodynamically unstable and requires immediate surgical intervention to control the bleeding. Needle thoracostomy over the 2nd intercostal space (D) is a procedure used to decompress tension pneumothorax, not to repair a penetrating cardiac injury. It is not the appropriate surgical approach in this scenario. Surgical adhesive glue (E) is not the best definitive surgical approach for a full thickness penetrating injury to the right ventricular free wall. Sutures are required to provide hemostasis and closure of the defect. | |||
82 | A post-mortem lung examination of a 68-year-old male overweight male with evidence of chronic lower extremity edema, a 60 pack-year smoking history and daily productive cough would be most likely to reveal: Options: (A): Hypereosinophilia (B): Reid Index > 50% (C): Non-caseating granulomas (D): Evidence of a necrotizing infection (E): Keratin pearls | Reid Index > 50% | Correct | The correct choice is (B) Reid Index > 50%. Explanation: The Reid Index is a measure of the thickness of the mucous glands in the bronchial wall compared to the thickness of the bronchial wall itself. A Reid Index greater than 50% is indicative of chronic bronchitis, which is characterized by excessive mucus production and inflammation of the bronchial tubes. In this case, the patient has a history of chronic lower extremity edema, which can be a sign of heart failure. The daily productive cough and smoking history also suggest chronic bronchitis. Therefore, a post-mortem lung examination would most likely reveal a Reid Index greater than 50%, confirming the diagnosis of chronic bronchitis. | |||
83 | A 54-year-old male makes an appointment with his primary care physician due to chronic fatigue that has left him unable to hike or do other physically demanding activities with his friends. He has well-controlled hypertension and diabetes but has otherwise been healthy. He does not smoke but drinks socially with his friends. Physical exam reveals enlarged nodules that are not tender to palpation. A biopsy is obtained showing a characteristic change in chromosome 18. The regulation of which of the following proteins will be most abnormal in this patient? Options: (A): Caspase-8 (B): Caspase-9 (C): CD15 (D): Cyclin-dependent kinase 4 (E): Ras pathway transcription factors | Caspase-9 | Correct | The correct choice is (B) Caspase-9. Explanation: The patient's presentation of chronic fatigue, enlarged nodules, and characteristic change in chromosome 18 suggests a diagnosis of chronic lymphocytic leukemia (CLL). CLL is a type of cancer that affects the white blood cells, specifically B lymphocytes. Caspases are a family of proteins that play a crucial role in apoptosis, or programmed cell death. Caspase-8 and caspase-9 are two important members of this family. Caspase-8 is involved in the extrinsic pathway of apoptosis, which is triggered by external signals. Caspase-9, on the other hand, is involved in the intrinsic pathway of apoptosis, which is triggered by internal signals such as DNA damage or cellular stress. In CLL, there is an abnormality in chromosome 18, which often involves a deletion of a portion of the long arm of the chromosome (del(18q)). This deletion can lead to dysregulation of caspase-9, resulting in impaired apoptosis and the accumulation of abnormal lymphocytes. Therefore, in this patient with CLL and a characteristic change in chromosome 18, the regulation of caspase-9 will be most abnormal. | |||
84 | A 44-year-old African-American woman comes to the physician for a routine examination. She is concerned about cancer because her uncle died of metastatic melanoma 1 year ago. She has no history of serious illness and does not take any medication. She has been working in a law firm for the past 20 years and travels to the Carribean regularly with her husband. Examination of her skin shows no abnormal moles or warts. This woman is at greatest risk of which of the following types of melanoma? Options: (A): Desmoplastic (B): Nodular (C): Acral lentiginous (D): Lentigo maligna (E): Superficial spreading | Acral lentiginous | Correct | The correct answer is (C) Acral lentiginous. Explanation: Based on the information provided, the woman is African-American and has no abnormal moles or warts on her skin. Acral lentiginous melanoma is a subtype of melanoma that primarily affects individuals with darker skin types, such as African-Americans. It commonly occurs on the palms of the hands, soles of the feet, and under the nails. This subtype is not related to sun exposure, which is consistent with the woman's history of working indoors and traveling to the Caribbean. Therefore, she is at greatest risk of acral lentiginous melanoma. | |||
85 | A 60-year-old woman is brought to the clinic by her daughter for evaluation. The daughter reports that her mother has recently been having difficulty combing her hair in the mornings. The patient’s family history is significant for an ischemic stroke in her father. The patient’s past medical history is positive for diverticulosis. She takes no medication. Her blood pressure is 120/70 mm Hg, heart rate is 75/min, respiratory rate is 14/min, and temperature is 37.6°C (99.7°F). On physical examination, the patient’s neck is stiff and she also has bilateral shoulder tenderness; muscle strength is intact. Laboratory work is performed and presented below: Hemoglobin 12.9 g/dL Hematocrit 37.7% Leukocyte count 5,500/mm3 Neutrophils 65% Lymphocytes 30% Monocytes 5% Mean corpuscular volume 82.2 μm3 Platelet count 190,000/mm3 Erythrocyte sedimentation rate 65 mm/h C-reactive protein 44 mg/dL For which of the symptoms below should the patient be screened? Options: (A): Uveitis (B): Jaw claudication (C): Heliotrope rash (D): Gastroesophageal reflux (E): Pink plaques with silvery scales | Jaw claudication | Correct | The correct answer is (B) Jaw claudication. Jaw claudication refers to pain in the jaw muscles that occurs with chewing or talking. It is a common symptom of giant cell arteritis (GCA), also known as temporal arteritis. GCA is an inflammatory condition that affects the medium and large arteries, particularly the temporal arteries. It is more common in individuals over the age of 50, and women are affected more often than men. In this case, the patient is a 60-year-old woman who presents with difficulty combing her hair in the mornings. This symptom, along with the presence of a stiff neck and bilateral shoulder tenderness, raises suspicion for GCA. Other symptoms of GCA may include headache, scalp tenderness, vision changes, fatigue, and weight loss. The laboratory findings in this patient are also consistent with GCA. The elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels indicate an inflammatory process. These markers are often elevated in GCA. Therefore, given the patient's symptoms, physical examination findings, and laboratory results, she should be screened for jaw claudication to further evaluate for the possibility of GCA. | |||
86 | A 30-year-old woman comes to the physician because she has been unable to conceive for 3 years. Analysis of her husband's semen has shown normal sperm counts during this time. The patient also reports episodic pelvic and back pain accompanied by painful diarrhea for 5 years. She has about one such episode on average per month for 4–6 days. She has taken ibuprofen for the pain, which has provided some relief. Menses have occurred at regular 29-day intervals since menarche at the age of 14 years and last for 7 days. She is sexually active with her husband and does not use contraception. Vital signs are within normal limits. Pelvic and bimanual examinations are normal; rectal examination is unremarkable. A hysterosalpingogram 6 months prior showed normal results. Which of the following is the most likely underlying mechanism of this patient's symptoms? Options: (A): Loss of fallopian tube function following infection (B): Smooth muscle tumor arising from the myometrium (C): Increased secretion of prolactin (D): Endometrial tissue outside the uterine cavity (E): Increased secretion of androgens and luteinizing hormone | Endometrial tissue outside the uterine cavity | Correct | The correct choice is (D): Endometrial tissue outside the uterine cavity. Explanation: This patient's symptoms are consistent with endometriosis. Endometriosis is a condition in which endometrial tissue, which normally lines the inside of the uterus, grows outside the uterus. This tissue can implant and grow on the pelvic organs, such as the ovaries, fallopian tubes, and the peritoneum. The patient's symptoms of pelvic and back pain, painful diarrhea, and painful periods are classic symptoms of endometriosis. The pain is typically cyclical and occurs around the time of menstruation. The pain can be caused by the presence of endometrial tissue outside the uterus, which responds to hormonal changes during the menstrual cycle. The patient's inability to conceive for 3 years may also be related to endometriosis. Endometriosis can cause infertility by affecting the function of the fallopian tubes, ovaries, and uterus. The presence of endometrial tissue outside the uterus can lead to the formation of adhesions and scar tissue, which can block the fallopian tubes and prevent the sperm from reaching the egg. The hysterosalpingogram, which showed normal results, suggests that the fallopian tubes are not the cause of the patient's infertility. This further supports the diagnosis of endometriosis as the underlying mechanism of her symptoms. Therefore, the most likely underlying mechanism of this patient's symptoms is endometrial tissue outside the uterine cavity. | |||
87 | A 55-year-old truck driver is brought to a physician by his wife. She states that her husband developed a fever and began feeling weak 3 days ago, but has refused medical help. He has been unable to go to work because of his symptoms. The patient has been previously hospitalized for a tricuspid valve replacement surgery 1 year ago and takes aspirin daily. The medical history is also relevant for myocardial infarction 3 years ago and hypertension for the past 10 years, for which he takes lisinopril. His blood pressure is 140/80 mm Hg, the pulse is 82/min, the respirations are 18/minute, and the temperature is 37.2°C (98.9°F). On examination, several hemorrhages are noted on the nail beds of several fingers. Which of the following findings would be most helpful in establishing a diagnosis? Options: (A): Thickened valve with multiple small vegetations (B): Bicuspid valve (C): Friable irregular masses attached to the valve (D): Papillary muscle rupture (E): Annular calcification | Friable irregular masses attached to the valve | Correct | The correct choice is (C): Friable irregular masses attached to the valve. Explanation: The patient's history of tricuspid valve replacement surgery and the presence of fever, weakness, and nail bed hemorrhages suggest infective endocarditis. The most common cause of infective endocarditis in patients with prosthetic valves is Staphylococcus epidermidis, which is a common skin commensal. The presence of friable irregular masses attached to the valve is consistent with infective endocarditis. These masses, known as vegetations, are composed of fibrin, platelets, and microorganisms. They can embolize, leading to systemic complications such as septic emboli and abscess formation. Thickened valve with multiple small vegetations (choice A) is more characteristic of nonbacterial thrombotic endocarditis, which is associated with hypercoagulable states such as malignancy. Bicuspid valve (choice B) is a congenital abnormality and is not associated with the symptoms and findings described in the patient. Papillary muscle rupture (choice D) is a complication of myocardial infarction and would present with acute onset of severe mitral regurgitation and pulmonary edema. Annular calcification (choice E) is a degenerative process seen in elderly patients and is not associated with the symptoms and findings described in the patient. | |||
88 | A previously healthy 30-year-old woman comes to the physician for the evaluation of pain during sexual intercourse for 6 months. She also reports frequent episodes of crampy pelvic pain that starts one day before menses and lasts for 7 days. Her symptoms are not relieved with pain medication. Menses occur at regular 28-day intervals and last 5 days. Her last menstrual period was 2 weeks ago. She is sexually active with her husband. She uses a combined oral contraceptive pill. Her vital signs are within normal limits. Physical examination shows rectovaginal tenderness. Cervical and urethral swabs are negative. Transvaginal ultrasonography shows no abnormalities. Which of the following is the most appropriate next step in management? Options: (A): Measurement of CA-125 levels (B): Hysterectomy (C): Laparoscopy (D): Hysteroscopy (E): CT scan of the abdomen and pelvis | Laparoscopy | Correct | The correct choice is (C) Laparoscopy. Explanation: The patient's symptoms of pain during sexual intercourse, crampy pelvic pain before menses, and rectovaginal tenderness are suggestive of endometriosis. Endometriosis is a condition where the tissue that normally lines the inside of the uterus (endometrium) grows outside the uterus, leading to pain and other symptoms. In this case, the patient's symptoms are not relieved with pain medication, and the physical examination findings are consistent with endometriosis. Transvaginal ultrasonography may not always detect endometriosis, as the implants can be small and difficult to visualize. Laparoscopy is the gold standard for diagnosing endometriosis. It involves making small incisions in the abdomen and inserting a camera to visualize the pelvic organs. During laparoscopy, the surgeon can directly visualize and biopsy any endometrial implants to confirm the diagnosis. Measurement of CA-125 levels (option A) is not the most appropriate next step in management. CA-125 is a tumor marker that can be elevated in certain conditions, including endometriosis. However, CA-125 levels are not specific for endometriosis and can also be elevated in other conditions, such as ovarian cancer. Therefore, CA-125 levels alone are not sufficient for diagnosing endometriosis. Hysterectomy (option B) is not indicated as the initial management for endometriosis. Hysterectomy involves the removal of the uterus and is a more definitive treatment option for patients who have completed childbearing and have severe symptoms that are not responsive to conservative management. Hysteroscopy (option D) is a procedure that involves inserting a thin, lighted tube through the vagina and cervix to visualize the inside of the uterus. It is not the most appropriate next step in management for this patient because her symptoms and physical examination findings are suggestive of endometriosis, which involves the tissue outside the uterus. CT scan of the abdomen and pelvis (option E) is not the most appropriate next step in management. While a CT scan can provide detailed images of the abdomen and pelvis, it is not the first-line diagnostic modality for endometriosis. Laparoscopy is the preferred method for visualizing and diagnosing endometriosis. | |||
89 | A 50-year-old man visits his physician after 20 years of not seeking any medical care. He is concerned about his health after a colleague recently had a heart attack. The patient has no active complaints and says he feels healthy; however, he does not exercise regularly and lives a sedentary lifestyle. He is employed as an administrative position at a local college, and is seated at a desk most of the day. His father had a heart attack at age 54 and his mother is still alive with no health concerns. He does not smoke, only drinks socially, and does not use drugs. Today, his blood pressure is 130/90 mm Hg, pulse is 84/min, and respiratory rate is 14/min. Physical examination reveals an obese male with no significant findings. An ECG shows no abnormalities, and laboratory testing shows the following: Laboratory test Serum glucose (fasting) 105 mg/dL Serum electrolytes Sodium 142 mEq/L Potassium 3.9 mEq/L Chloride 101 mEq/L Serum creatinine 0.8 mg/dl Blood urea nitrogen 10 mg/dl Cholesterol, total 250 mg/dL HDL-cholesterol 35 mg/dL LDL-cholesterol 186 mg/dL Triglycerides 170 mg/dL Urinalysis Glucose negative Ketones negative Leucocytes negative Nitrites negative Red blood cells (RBC) negative Casts negative Which of the following lab abnormalities in this patient is an indication for treatment? Options: (A): Blood pressure reading (B): Patient’s weight (C): High triglyceride levels (D): High LDL-cholesterol (E): Serum glucose level | High LDL-cholesterol | Correct | The correct answer is (D): High LDL-cholesterol. Explanation: High LDL-cholesterol levels are an indication for treatment in this patient. LDL-cholesterol is commonly referred to as "bad" cholesterol because it contributes to the development of atherosclerosis, which can lead to heart disease and stroke. In this patient, the LDL-cholesterol level is 186 mg/dL, which is above the recommended target level of less than 100 mg/dL for individuals at high risk of cardiovascular disease. Given the patient's sedentary lifestyle, family history of heart disease, and high total cholesterol level, it is important to address the elevated LDL-cholesterol to reduce his risk of cardiovascular events. Treatment options may include lifestyle modifications such as dietary changes and increased physical activity, as well as medication therapy if necessary. | |||
90 | A 26-year-old woman is brought to the emergency department 20 minutes after being involved in a high-speed motor vehicle collision in which she was a restrained passenger. On arrival, she is lethargic and incoherent. She has severe facial lacerations and is in respiratory distress. Her pulse is 130/min, respirations are 29/min, and blood pressure is 90/58 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 70%. Examination shows multiple facial lacerations. There is dullness to percussion and decreased breath sounds over the left lung base. Abdominal examination shows diffuse tenderness with no guarding or rebound. Bowel sounds are normal. The remainder of the examination shows no abnormalities. Her hemoglobin concentration is 12.1 g/dL. An x-ray of the chest shows a fractured left second rib, depression of the left mainstem bronchus, deviation of the nasogastric tube to the right, and a widened mediastinum. Which of the following is the most likely diagnosis? Options: (A): Diaphragmatic rupture (B): Traumatic bronchial rupture (C): Thoracic aortic rupture (D): Cardiac tamponade (E): Tension pneumothorax | Thoracic aortic rupture | Correct | The correct answer is (C) Thoracic aortic rupture. Explanation: The patient in this scenario presents with multiple signs and symptoms that are consistent with a thoracic aortic rupture. The mechanism of injury, a high-speed motor vehicle collision, is a common cause of thoracic aortic rupture. The patient's presentation of lethargy, incoherence, severe facial lacerations, and respiratory distress suggests significant trauma. The vital signs, including tachycardia, tachypnea, and hypotension, are indicative of shock. The decreased breath sounds and dullness to percussion over the left lung base suggest a hemothorax, which can occur with aortic rupture. The widened mediastinum on chest x-ray is a classic finding in thoracic aortic rupture. The other options listed, including diaphragmatic rupture, traumatic bronchial rupture, cardiac tamponade, and tension pneumothorax, do not fully explain the patient's presentation and findings. | |||
91 | A 26-year-old G1P0 woman presents to her primary care physician’s office with feelings of anxiety and trouble with sleep. She finds it difficult initiating sleep, occasionally has palpitations, and feels fatigued. She denies having similar symptoms in the past or starting any new medications or illicit drugs. She is currently 10 weeks pregnant and is closely followed by her obstetrician. Her temperature is 98.6°F (37°C), blood pressure is 125/70 mmHg, pulse is 105/min, and respirations are 18/min. On physical exam, the patient is mildly diaphoretic. The skin is warm and the thyroid gland is diffusely enlarged with thyroid bruits. Laboratory studies are significant for a thyroid-stimulating hormone level of 0.01 µU/mL (normal is 0.5-5.0 µU/mL) and an elevated free thyroxine (FT4) that is inappropriate for her pregnancy. Which of the following is the best treatment option for this patient? Options: (A): Methimazole (B): Observation (C): Propylthiouracil (D): Radioiodine therapy (E): Thyroidectomy | Propylthiouracil | Correct | The correct choice is (C) Propylthiouracil. Explanation: This patient is presenting with symptoms of hyperthyroidism, including anxiety, trouble with sleep, palpitations, and fatigue. On physical examination, she has a diffusely enlarged thyroid gland with thyroid bruits. Laboratory studies show a low thyroid-stimulating hormone (TSH) level and an elevated free thyroxine (FT4) level, which is inappropriate for her pregnancy. Propylthiouracil is the best treatment option for this patient. It is an antithyroid medication that inhibits the synthesis of thyroid hormones by blocking the enzyme thyroperoxidase. It is safe to use during pregnancy and is the preferred treatment option in the first trimester. Methimazole, another antithyroid medication, is contraindicated in the first trimester of pregnancy due to an increased risk of congenital abnormalities. Radioiodine therapy and thyroidectomy are not recommended during pregnancy. Observation alone is not appropriate in this case because the patient is symptomatic and her thyroid function tests are abnormal. Prompt treatment is necessary to control her hyperthyroidism and prevent complications. | |||
92 | A 32-year-old woman comes to the physician because of a 3-week history of intermittent loose stools and a 1.2-kg (2.6-lb) weight loss. She immigrated to the US from Uganda 6 weeks ago. Abdominal examination shows diffuse tenderness with no guarding or rebound. The liver is firm and palpable 3 cm below the right costal margin, and the spleen is palpable just below the left costal margin. Her leukocyte count is 12,800/mm3 (12% eosinophils). Stool culture shows several oval-shaped eggs with lateral spines. Microscopic examination of a liver biopsy specimen shows granulomatous inflammation with periportal fibrosis. Exposure to which of the following is most likely to have played a role in the development of this patient's symptoms? Options: (A): Tsetse flies (B): Undercooked pork meat (C): Undercooked fish meat (D): Dog feces (E): Freshwater snails | Freshwater snails | Correct | The correct answer is (E) Freshwater snails. Explanation: The patient's symptoms, including intermittent loose stools, weight loss, diffuse tenderness on abdominal examination, palpable liver and spleen, and elevated leukocyte count with eosinophilia, are consistent with hepatosplenic schistosomiasis. Schistosomiasis is caused by infection with parasitic worms called schistosomes, which are transmitted through contact with contaminated freshwater. The eggs of the schistosomes are released into the water through the feces or urine of infected individuals. These eggs hatch into larvae (miracidia) that infect freshwater snails. The larvae then develop into cercariae, which are released from the snails into the water. Human infection occurs when individuals come into contact with contaminated water, such as by swimming or bathing in freshwater lakes or rivers. Once inside the human body, the cercariae penetrate the skin and migrate to the liver, where they mature into adult worms. The adult worms then migrate to the veins of the intestines or bladder, where they lay eggs. The eggs can cause inflammation and fibrosis in the liver, leading to hepatosplenic schistosomiasis. The presence of oval-shaped eggs with lateral spines in the stool culture and granulomatous inflammation with periportal fibrosis on liver biopsy are consistent with schistosomiasis. Additionally, the patient's recent immigration from Uganda, where schistosomiasis is endemic, further supports this diagnosis. Therefore, exposure to freshwater snails is most likely to have played a role in the development of this patient's symptoms. | |||
93 | A 3-month-old girl is brought to a pediatrician by her parents. She has central cyanosis without signs of respiratory distress or signs of heart failure. An echocardiogram reveals severe pulmonary outflow obstruction, right ventricular hypertrophy, a ventricular septal defect, and an overriding of the aorta. An elective primary surgical repair is planned at 4 months of age. Which of the following statements is true about this girl’s condition? Options: (A): The tricuspid valve is the most common valve affected by bacterial endocarditis in uncorrected tetralogy of Fallot. (B): Normal hemoglobin in patients with tetralogy of Fallot does not rule out iron deficiency anemia. (C): Cerebral arterial thrombosis is more common than cerebral venous thrombosis. (D): Refractory heart failure is a common complication of tetralogy of Fallot. (E): The most common age of presentation for brain abscess is between 6 and 12 months. | Normal hemoglobin in patients with tetralogy of Fallot does not rule out iron deficiency anemia. | Correct | The correct choice is (B) Normal hemoglobin in patients with tetralogy of Fallot does not rule out iron deficiency anemia. Explanation: Tetralogy of Fallot is a congenital heart defect characterized by four anatomical abnormalities: pulmonary outflow obstruction, right ventricular hypertrophy, a ventricular septal defect, and an overriding aorta. In this condition, blood flow to the lungs is decreased, leading to cyanosis. Iron deficiency anemia is a common condition in infants and children, and it can coexist with tetralogy of Fallot. Normal hemoglobin levels in patients with tetralogy of Fallot do not rule out iron deficiency anemia. Iron deficiency anemia can occur due to inadequate iron intake, poor absorption, or increased iron requirements. It is important to assess iron status in patients with tetralogy of Fallot and provide appropriate supplementation if necessary. The other options are incorrect because: (A) The tricuspid valve is not the most common valve affected by bacterial endocarditis in uncorrected tetralogy of Fallot. Bacterial endocarditis can affect any valve, but it is more commonly associated with the pulmonary valve in patients with tetralogy of Fallot. (C) Cerebral arterial thrombosis and cerebral venous thrombosis are both potential complications of tetralogy of Fallot, but there is no evidence to suggest that one is more common than the other. (D) Refractory heart failure is not a common complication of tetralogy of Fallot. Heart failure can occur in severe cases of tetralogy of Fallot, but it is not a common complication. (E) The most common age of presentation for brain abscess is not between 6 and 12 months. Brain abscess can occur at any age and is not specifically associated with tetralogy of Fallot. | |||
94 | Six days after undergoing surgical repair of a hip fracture, a previously healthy 79-year-old woman is agitated and confused. She is unarousable during the day, but then is awake and impulsive during the night, requiring frequent reorientation. Her husband says that she usually drinks one to two glasses of wine weekly. Her only current medication is oxycodone for pain. Her vital signs are within normal limits. She is distressed and oriented to person but not to place or time. Neurologic examination shows inattentiveness but no focal deficits. Urine dipstick is normal. Which of the following is the most likely cause of her current condition? Options: (A): Dementia (B): Alcohol withdrawal (C): Opioid intoxication (D): Delirium (E): Urinary tract infection | Delirium | Correct | The correct choice is (D) Delirium. Explanation: Delirium is the most likely cause of the patient's current condition. Delirium is a state of acute confusion and altered consciousness that is often caused by an underlying medical condition or medication. In this case, the patient's symptoms of agitation, confusion, and inattentiveness are consistent with delirium. The fact that she is unarousable during the day and awake and impulsive at night suggests a disturbance in her sleep-wake cycle, which is common in delirium. The patient's history of undergoing surgical repair of a hip fracture and her use of oxycodone for pain are important clues. Surgery and the use of opioids can both contribute to the development of delirium. Additionally, the patient's age of 79 years is a risk factor for delirium, as older adults are more susceptible to developing this condition. The other options can be ruled out based on the information provided: - Dementia is a chronic condition characterized by progressive cognitive decline, whereas delirium is an acute confusional state. The patient's symptoms are more consistent with delirium than dementia. - Alcohol withdrawal typically occurs in individuals with a history of heavy alcohol use who abruptly stop drinking. The patient's history of drinking one to two glasses of wine weekly is unlikely to cause alcohol withdrawal. - Opioid intoxication can cause sedation and respiratory depression, but it is unlikely to cause the patient's symptoms of agitation and confusion. - Schizophrenia is a chronic mental disorder characterized by hallucinations, delusions, and disorganized thinking. The patient's symptoms are not consistent with schizophrenia. - While a urinary tract infection (UTI) can cause confusion in older adults, the patient's normal urine dipstick makes a UTI less likely as the primary cause of her symptoms. | |||
95 | A 54-year-old woman with a past medical history of mental retardation, hypertension, and diabetes presents to the emergency department with a change in her behavior. Her caretakers state that the patient’s gait suddenly became ataxic, and she became less responsive than her normal non-verbal baseline. Her temperature is 98.5°F (36.9°C), blood pressure is 125/68 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 99% on room air. Physical exam is notable for an unremarkable HEENT exam with normal facial features and no signs of airway compromise. Neurological exam is remarkable for new onset spasticity. The patient has 3+ reflexes and a positive Babinski sign. Musculoskeletal exam is only notable for symmetric swelling and deformities of the patient’s hands bilaterally. Additionally, there is a "clunk" when posterior force is applied to the head while anterior force is applied to the cervical spine. Which of the following is the most likely risk factor that predisposed this patient to this condition? Options: (A): Cerebral palsy (B): Diabetes mellitus (C): Down syndrome (D): Hypertension (E): Rheumatoid arthritis | Rheumatoid arthritis | Correct | The correct answer is (E) Rheumatoid arthritis. Explanation: The patient in this case has a history of mental retardation, hypertension, and diabetes, but the most likely risk factor that predisposed her to her current condition is rheumatoid arthritis. Rheumatoid arthritis is an autoimmune disease that primarily affects the joints, causing inflammation, pain, and deformities. In this case, the patient has symmetric swelling and deformities of the hands, which are characteristic of rheumatoid arthritis. Additionally, the "clunk" when posterior force is applied to the head while anterior force is applied to the cervical spine suggests atlantoaxial instability, which is a complication of rheumatoid arthritis. This instability can compress the spinal cord and lead to neurological symptoms such as spasticity and ataxia, which the patient is experiencing. The positive Babinski sign and increased reflexes are also consistent with spinal cord compression. Therefore, rheumatoid arthritis is the most likely risk factor in this patient's case. | |||
96 | A 24-year-old man is brought to the emergency department 15 minutes after he sustained a stab wound to the left chest just below the clavicle. On arrival, he has rapid, shallow breathing and appears anxious. His pulse is 135/min, respirations are 30/min and shallow, and palpable systolic blood pressure is 80 mm Hg. He is intubated and mechanically ventilated. Infusion of 0.9% saline is begun. Five minutes later, his pulse is 133/min and blood pressure is 82/45 mm Hg. Examination shows no active external bleeding. There is a 2.5-cm single stab wound to the left chest at the 4th intercostal space at the midclavicular line. Cardiovascular examination shows muffled heart sounds and jugular venous distention. Breath sounds are normal. Further evaluation of this patient is most likely to show which of the following findings? Options: (A): Tracheal deviation toward the right side (B): Hemoptysis (C): A drop in systolic blood pressure of 14 mmHg during inspiration (D): Herniation of the stomach into the chest (E): Paradoxical motion of part of the chest with breathing " | A drop in systolic blood pressure of 14 mmHg during inspiration | Correct | The correct choice is (C): A drop in systolic blood pressure of 14 mmHg during inspiration. Explanation: Based on the information provided, the patient has sustained a stab wound to the left chest, resulting in symptoms of rapid, shallow breathing, anxiety, tachycardia, and hypotension. The physical examination findings of muffled heart sounds and jugular venous distention suggest the presence of a tension pneumothorax. In a tension pneumothorax, air accumulates in the pleural space and causes a shift of the mediastinum to the opposite side. This can compress the great vessels and impair venous return to the heart, leading to decreased cardiac output and hypotension. The drop in systolic blood pressure of 14 mmHg during inspiration is a classic finding in tension pneumothorax. Tracheal deviation toward the right side (option A) is not likely in this case, as there is no mention of any abnormal tracheal position. Hemoptysis (option B) refers to coughing up blood, which is not mentioned in the patient's presentation. Herniation of the stomach into the chest (option D) is not likely in this case, as there is no mention of any gastrointestinal symptoms or findings. Paradoxical motion of part of the chest with breathing (option E) refers to a condition called flail chest, which is characterized by multiple rib fractures resulting in a segment of the chest wall moving in the opposite direction to the rest of the chest during respiration. This is not likely in this case, as there is no mention of any chest wall abnormalities or trauma. Therefore, the most likely finding in this patient is a drop in systolic blood pressure of 14 mmHg during inspiration, indicating a tension pneumothorax. | |||
97 | A 40-year-old man presents to his primary-care doctor for a follow-up of his hypertension. He is asymptomatic at his office visit and denies any new complaints. He has a 10-year history of hypertension that remains poorly controlled on maximum doses of lisinopril, hydrochlorothiazide, and amlodipine. His past medical history is otherwise unremarkable. He has no smoking history, drinks alcohol occasionally, and denies any illicit drug use. His father required a kidney transplant in his forties. The physical exam is notable for palpable flank masses bilaterally. Laboratory studies show a creatinine of 2.5. The physician orders a renal ultrasound, and the results are shown. Which of the following is the most appropriate test to screen for additional complications of this patient's condition? Options: (A): Colonoscopy (B): Esophagogastroduodenoscopy (C): Liver function tests (D): MR angiography of the brain (E): Serum amylase and lipase | MR angiography of the brain | Correct | The correct choice is (D) MR angiography of the brain. Explanation: Based on the patient's history and physical exam findings, the most likely diagnosis is polycystic kidney disease (PKD). PKD is a genetic disorder characterized by the development of multiple cysts in the kidneys. It is associated with hypertension, as seen in this patient, and can lead to progressive kidney damage and renal failure. The presence of palpable flank masses and an elevated creatinine level further support the diagnosis of PKD. However, PKD is not only limited to the kidneys. It can also affect other organs, including the brain. One of the potential complications of PKD is the development of intracranial aneurysms. These aneurysms can be asymptomatic until they rupture, leading to a potentially life-threatening condition called subarachnoid hemorrhage. Therefore, it is important to screen for the presence of intracranial aneurysms in patients with PKD. MR angiography of the brain is the most appropriate test to screen for intracranial aneurysms in this patient. It is a non-invasive imaging technique that can provide detailed images of the blood vessels in the brain, allowing for the detection of aneurysms. Colonoscopy and esophagogastroduodenoscopy are not indicated in this patient as there are no symptoms or risk factors suggestive of gastrointestinal pathology. Liver function tests are not necessary in this patient as there are no symptoms or risk factors suggestive of liver disease. Serum amylase and lipase are tests used to evaluate for pancreatic pathology, such as pancreatitis. There are no symptoms or risk factors suggestive of pancreatic disease in this patient. | |||
98 | A 17-year-old female is brought to the emergency room by her father because she has been experiencing shortness of breath and chest pain. She says that the chest pain is worse when she breathes or coughs. Furthermore, on the way to the hospital she noticed that there were specks of blood on a tissue that she coughed into. She has no previous medical history and does not recall anything that could have provoked these symptoms. On presentation her temperature is 99°F (37.2°C), blood pressure is 107/65 mmHg, pulse is 102/min, respirations are 21/min, and O2 saturation is 91% on room air. Further testing shows a large filling defect in the pulmonary vessels, and the patient is started on an appropriate treatment intravenously. After drug administration, the effects of the drug are monitored using a standard blood test. Surprisingly, the test results come back within normal parameters. The most likely underlying cause of this patient's symptoms has which of the following modes of inheritance? Options: (A): Autosomal dominant (B): Autosomal recessive (C): Autosomal partial dominance (D): X-linked dominant (E): X-linked recessive | Autosomal dominant | Correct | The correct answer is (A) Autosomal dominant. Explanation: The patient's symptoms, including shortness of breath, chest pain worsened by breathing or coughing, and the presence of blood in her coughed-up tissue, are consistent with a pulmonary embolism. A pulmonary embolism occurs when a blood clot, usually from the deep veins of the legs, travels to the pulmonary arteries and blocks blood flow to the lungs. The large filling defect seen on further testing confirms the presence of a blood clot in the pulmonary vessels. Autosomal dominant inheritance means that a single copy of the mutated gene is sufficient to cause the disease. In this case, the patient's symptoms are likely due to an inherited clotting disorder, such as factor V Leiden mutation or antithrombin III deficiency, which are both autosomal dominant disorders. These disorders increase the risk of developing blood clots, including pulmonary embolism. The fact that the patient's symptoms are not provoked by any known trigger and that her blood test results are within normal parameters after treatment suggest an underlying genetic cause rather than an acquired condition. Autosomal recessive, autosomal partial dominance, X-linked dominant, and X-linked recessive inheritance patterns are less likely in this case, as they are not commonly associated with clotting disorders that present with the symptoms described. | |||
99 | A 26-year-old male presents to his primary care physician with complaints of burning with urination, penile discharge, and intermittent fevers. A urethral smear shows gram negative diplococci within white blood cells. The organism grows well when cultured on Thayer-Martin agar. The patient is prescribed a course of ceftriaxone and the infection resolves without further complication. One year later, the patient returns with the same infection. Which of the following best explains this lack of lasting immunity? Options: (A): Exotoxin release (B): Antigenic variation (C): Polysaccharide capsule (D): Bruton's agammaglobulinemia (E): Lack of necessary vaccination | Antigenic variation | Correct | The correct choice is (B) Antigenic variation. Explanation: Antigenic variation refers to the ability of certain pathogens to change their surface antigens in order to evade the immune response. In this case, the patient presents with symptoms of a urinary tract infection caused by gram-negative diplococci, which is most likely Neisseria gonorrhoeae. This bacterium is known to undergo antigenic variation, specifically in its surface protein called the pilin. The pilin protein is responsible for mediating attachment to host cells and is a target for the immune system. However, N. gonorrhoeae can alter the structure of its pilin protein through genetic recombination, leading to the production of different variants. This allows the bacterium to evade the immune response and establish reinfection even after a previous episode of infection and treatment. Exotoxin release (A) is not the correct answer because it does not explain the lack of lasting immunity in this case. Exotoxins are toxins released by certain bacteria that can cause damage to host tissues, but they do not directly affect the immune response or the development of immunity. Polysaccharide capsule (C) is not the correct answer because it also does not explain the lack of lasting immunity. Polysaccharide capsules can help bacteria evade the immune system by preventing phagocytosis, but they do not directly affect the development of immunity. Bruton's agammaglobulinemia (D) is not the correct answer because it is a genetic disorder characterized by a lack of B cells and immunoglobulins, leading to a deficiency in antibody production. This condition would result in a general lack of immune response, rather than a lack of lasting immunity specifically against N. gonorrhoeae. Lack of necessary vaccination (E) is not the correct answer because it assumes that there is a vaccine available for N. gonorrhoeae, which is not the case. Currently, there is no vaccine available for this bacterium. | |||
100 | A 37-year-old man with no significant past medical history is rear-ended in a motor vehicle accident. He reported significant neck pain to emergency responders, but otherwise denies weakness, numbness or tingling in his extremities. His vitals on presentation to the ED are HR 90, BP 140/80, RR 20, SpO2 98%. What is the most appropriate next step upon presentation to the emergency room? Options: (A): Lateral cervical film (B): Three view cervical spine series (C): Cervical immobilization (D): IV methylprednisolone (E): Observation overnight | Cervical immobilization | Correct | The correct answer is (C) Cervical immobilization. Explanation: In this scenario, the patient is a 37-year-old man who was rear-ended in a motor vehicle accident and presents with significant neck pain. However, he denies weakness, numbness, or tingling in his extremities. His vital signs are stable. Based on the provided context information, the patient meets the low-risk criteria for cervical spine injury evaluation. These criteria include a simple rear-end motor vehicle accident, the ability to sit up in the ED, ambulatory at any time, delayed onset of neck pain, and absence of midline cervical tenderness. According to the guidelines, patients who meet the low-risk criteria should undergo range-of-motion testing. If the patient is able to actively rotate their neck 45 degrees to the left and right, imaging is not necessary. Therefore, cervical immobilization is the most appropriate next step in this case. Lateral cervical film (option A) and three view cervical spine series (option B) are imaging modalities that may be considered if the patient does not meet the low-risk criteria or is unable to actively rotate their neck. However, in this case, imaging is not necessary as the patient meets the low-risk criteria and is able to actively rotate their neck. IV methylprednisolone (option D) is not indicated in the initial management of cervical spine injuries. It may be considered in certain cases of spinal cord injury, but there is no indication for its use in this scenario. Observation overnight (option E) may be considered in certain cases, but it is not the most appropriate next step in this scenario. Cervical immobilization is the initial step in the evaluation and management of cervical spine injuries. |