COMPLICATIONS OF DIABETES AND ITS ANAESTHETIC IMPLICATIONS

TREATMENT OF DIABETES

TREATMENT OF DIABETES

INSULIN REGIMENS ( SLIDING AND MODIFIED SLIDING SCALE)

• MODIFIED INSULIN SLIDING SCAKLE

COMPLICATIONS

ACUTE COMPLICATIONS :

1) Diabetic ketoacidosis ( DKA )

2) Hyperosmolar nonketotic coma

3) Hypogylcemia ( < 50mg /dl )

​

CHRONIC COMPLICATIONS �

MICROVASCULAR

• Eye diseases – macular edema and maculopathy
• Neuropathy - Sensory and motor neuropathy ( ‘stocking glove distribution “ )
• Foot fractures ( charcot’s joint )
• Autonomic neuropathy
• Nephropathy

MACROVASCULAR

Coronary artery disease

Cerebrovascular accidents

Peripheral vascular diseases

​

​

CARDIAC COMPLICATIONS

• Hypertension
• Peripheral arterial disease
• Systolic and diastolic dysfunction, related to:
• Coronary artery disease
• Hypertension
• Left ventricular hypertrophy
• Endothelial dysfunction
• Obesity
• Autonomic neuropathy

OTHERS

• Cataract
• Glaucoma
• Gastrointestinal : Gastroparesis , constipation and diarrohoea
• Genitourinary : Uropathy ,erectile dysfunction
• Dermatological
• Infection

​

DIABETIC KETOACIDOSIS( PATHOPHYSIOLOGY )

• More common in type 1 diabetes .
• Causes: An underlying infection ,missed insulin treatment and the first presentation of diabetes .

HYPEROSMOLAR HYPERGLYCEMIC NON-KETOTIC STATE (PATHOPHYSIOLOGY)

RISK FACTORS FOR HYPEROSMOLAR

• Major risk factor is  diabetes mellitus type 2( 50 -70 yrs )
• It may also occur in type 1 diabetes mellitus .
• Triggers – Infection ,stroke ,trauma
• Lack of sufficient insulin (but enough to prevent ketosis)
• Poor kidney function
• Poor fluid intake (dehydration)
• Certain medical conditions( CVA ,MI and Sepsis )
• Certain medications (Glucocorticoids ,phenytoin ,thiazides)

DIFFERENCES BETWEEN DKA AND HHS

PATHOPHYSIOLOGY OF AUTONOMIC NEUROPATHY

CLINICAL SIGNS OF AUTONOMIC NEUROPATHY�

• Hypertension
• Painless MI
• Orthostatic Hypotension
• Lack of heart rate variability
• Reduced heart rate response to atropine or propranolol
• Resting tachycardia
• Early satiety
• Neurogenic bladder
• Lack of sweating
• Impotence

​

​

• Genitourinary
• Neurogenic bladder (diabetic cystopathy)
• Erectile dysfunction
• Retrograde ejaculation
• Female sexual dysfunction (e.g. loss of vaginal lubrication).
• Metabolic
• Hypoglycemia unawareness
• Hypoglycemia-associated autonomic failure

​

Sudomotor

• Anhidrosis
• Heat intolerance
• Gustatory sweating
• Dry skin.

Pupillary

• Pupillomotor function impairment (e.g. decreased diameter of dark adapted pupil)
• Argyll-Robertson pupil.

​

HYPOGLYCEMIA UNAWARENESS

• A condition in which the patient does not respond with the appropriate autonomic warning symptoms before neuroglycopenia.
• The diagnosis in adults requires a plasma glucose level below 50 mg/dL.
• Symptoms: Adrenergic (sweating, tachycardia, palpitations, restlessness, pallor) and
• Treatment includes administration of sugar in the form of sugar cubes, glucose tablets, or soft drinks if the patient is conscious.
• Glucose 0.5 g/kg IV or glucagon 0.5–1 mg IV, intramuscularly, or subcutaneously if the patient is unconscious

• Respiratory:

Frequent infections

Reduced VC, FVC, FEV, DLCO.

• Gastrointestinal:
• Gastroparesis due to ganglion cell damage
• Postprandial vomiting, early satiety
• Delayed gastric emptying.
• Genitourinary:
• Erectile dysfunction
• Renal failure especially if age > 55 years and diabetes and hypertension coexist.
• Musculoskeletal system :
• Stiff joint syndrome

​

PREOPERATIVE DISCONTINUATION OF DRUGS

• Oral hypoglycemics should be discontinued 24–48 hours preoperatively.
• Sulfonylureas be avoided during the entire perioperative period because they block the myocardial potassium adenosine triphosphate (ATP) channels responsible for ischemia- and anesthetic-induced preconditioning.
• Short acting insulins should be withheld on the morning of surgery .
• Long acting and intermediate acting insulins should be reduced to 20 %night before surgery and 50% on the morning of the surgery .

​

EXAMINATION

​

• Document vitals, orthostatic vital signs and skin breakdown points
• Sensory examination
• Airway examination:
• Stiff joint syndrome:
• Seen in poorly controlled DM
• Reduced mobility of cervical, atlanto occiptal and TM joint occurs.
• Prayer sign: inability to approximate palmar surface of interphalangeal joints
• Palm print sign:
• Alteration in palm print when it is taken on paper
• Indicates interphalangeal joint stiffness.
• Fundoscopy for retinopathy
• Tests for autonomic dysfunction
• Back for edema and infection: Difficult to perform subarachnoid block .

​

INVESTIGATIONS

• CBC: Look for infection (leukocytosis).
• Urine routine for microalbuminuria
• Serum creatinine
• Fasting and postprandial blood sugar
• Glycosylated Hb( HbA1 C )
• Serum electrolytes
• ECG
• 2D echocardiography
• X-ray chest
• Morning of surgery investigations: Serum electrolytes, FBS, urine ketones.
• Emergency surgery: Acute illness can cause metabolic decompensation. These patients need full clinical and biochemical assessment

REGIONAL ANAESTHESIA

• Advantages:
• Avoids aspiration
• Better if difficult airway
• Patient is awake: Easy to recognize hypoglycemia
• Reduced incidence of DVT
• Reduced stress response to surgery
• Good postoperative analgesia
• Reduced chances of pulmonary infection.
• Disadvantages:
• Exaggerated hypotension especially if autonomic neuropathy present
• Increased risk of epidural abscess
• Caution if pre-existing neuropathy
• Increased risk of nerve injury.

​

​

Local anesthetic requirement is lower

Combination of LA with adrenaline may increase risk of ischemic or edematous nerve injury

Bradycardia may be unresponsive to atropine

Isoprenaline/1:10,000 adrenaline used in such cases

Chart pre-existing nerve damage as increased chance of nerve injury

Technique: May be difficult if edema is present.

• Contraindications:

Autonomic neuropathy

Infections.

​

GENERAL ANAESTHESIA

• General Anesthesia
• Advantages:
• Better cardiovascular stability
• Airway is protected from silent aspiration.
• Disadvantages:
• Difficult intubation
• Difficult to recognize hypoglycemia
• Altered elimination of drugs due to renal involvement
• Increased stress response

​

​

Principles of anesthesia management in a diabetic patient

• Timing: Diabetic patients should be placed first on the operating list. This shortens their preoperative fast and the risk of hypoglycemia and ketosis.
• Fasting: Undiagnosed gastroparesis may prolong retention of food in the stomach thereby increasing the risk of regurgitation and aspiration.
• A 12-hour fast may be beneficial in diabetic patients before surgery.
• IV fluids: Ringer’s lactate—Lactate undergoes gluconeogenesis in the liver and may complicate blood sugar control when given in large volumes.
• Normal saline infusions in large volumes increase risk of hyperchloremic acidosis.

​

• Monitoring: Frequent, rapid and accurate blood glucose measurement is essential in the anesthetized patient as the requirements for glucose and insulin in this period are unpredictable and hypoglycemia may go undetected.
• Standard monitoring: ECG, SpO2, BP, ETCO2 and temperature should be instituted.
• Postoperative wound healing and infection may be influenced by the adequacy of perioperative glycemic control.

​

​

Principles of anesthesia management in a diabetic patient

• Glucose supplementation: Diabetic patients receiving longer-acting insulin are at risk of hypoglycemia if glucose is not supplemented.
• 1. To prevent hypoglycemia and excessive catabolism and starvation ketosis
• 2. Perioperative administration of glucose enhances postoperative glucose utilization rates.
• Insulin supplementation:
• 1. Essential in patients with absolute insulin deficiency and infection to prevent lipolysis and proteolysis with resultant ketosis.
• 2. Some of the metabolic effects of the suppression of insulin secretion are reversed by intraoperative insulin infusion.

ANAESTHESIA

• Induction: Choice of agent for general anesthesia depends on severity of systemic diseases, such as coronary artery disease, nephropathy, hypertension and autonomic neuropathy.
• Induction with Etomidate or high dose Fentanyl (4–5 mcg/kg) with midazolam and/or thiopentone should be performed (exaggerated hypotension due to autonomic neuropathy is common).
• Awake fiberoptic bronchoscopy would be preferred technique for an anticipated difficult airway.

​

• Succinyl choline should be avoided in patients with extensive peripheral neuropathy due to risk of increased potassium release.
• Atracurium and mivacurium are preferred in presence of renal dysfunction
• Rocuronium may be used in rapid sequence induction.
• Epidural analgesia may help to attenuate neurohormonal response to stress and avoid systemic analgesics like NSAIDs and opioids which may have serious side effects in a diabetic patient.

​

MAINTENANCE

• Maintenance of anesthesia is with isoflurane or sevoflurane in an air oxygen mixture.
• Nitrous oxide may be used, though it should be avoided in an intestinal obstruction case due to bowel distension.
• Patients with perforative peritonitis and sepsis should be ventilated postoperatively to optimize their oxygen delivery.
• . Airway pressures after abdominal closure should be observed to decide about postoperative ventilation.
• Less severe cases can be ‘reversed’ and extubated at the end of surgery.
• The patient should have adequate recovery of airway reflexes prior to extubation.

POST -OPERATIVE CARE

• Postoperative management of diabetic patients requires meticulous monitoring of insulin requirements.
• Hyperglycemia has been associated with poor outcomes in postoperative and critically ill patients.
• The risks of hypoglycemia must also be considered.
• ADA recommends that glucose levels be maintained between 140 and 180 mg/dL in critically ill patients and that insulin treatment be initiated if serum glucose levels exceed 180 mg/dL.

​

ANAESTHETIC DRUGS THAT AFFECT THE BLOOD SUGAR LEVEL

• KETAMINE : It causes significant hyperglycemia .
• Etomidate: blocks adrenal steroidogenesis and hence cortisol synthesis and decreases the hyperglycemic response to surgery.
• Propofol: The effect of propofol on insulin secretion is not known. Diabetic patients show a reduced ability to clear lipids from the circulation.
• Halothane, enflurane, isoflurane and sevoflurane: in in vitro studies inhibit the insulin response to glucose in a reversible and dose-dependent manner.

ANAESTHETIC DRUGS THAT AFFECT THE BLOOD SUGAR LEVEL

• BENZODIAZEPINES : They reduce sympathetic stimulation but stimulate growth hormone secretion and result in a decrease in the glycemic response to surgery. These effects are minimal when midazolam is given in usual sedative doses.
• Opioids: High-dose opiate anesthetic techniques produce hemodynamic,hormonal and metabolic stability. However, midazolam and fentanyl may cause hyperglycemia by reducing glucose clearance.
• Ganglion-blocking agents: (used for hypotensive anesthesia previously) may block sympathetically mediated hepatic gluconeogenesis with resultant hypoglycemia.
• B-blockers: The use of b-blockers is associated with slower recovery from hypoglycemia

REFERENCES

• STOELTINGS COEXISTING DISEASES
• BARASH
• BJA JOURNAL 2015
• MORGAN

​

​

​

​

​

THANK YOU