Septic Shock
Case
Patient：a 50-year-old female, 60 kg, was admitted to the hospital for urinary tract stones.
History of present illness:
Three days before admission, she developed urinary frequency, urgency, dysuria, and mild lower abdominal pain, but did not seek medical attention. One day before admission, she developed fever with chills, with a peak temperature of 39.5°C. Her temperature decreased temporarily after taking antipyretics, but her symptoms did not improve significantly. On the morning of admission, she developed nausea and vomiting of gastric contents without hematemesis, followed by confusion and agitation. She was brought to the Emergency Department by her family and admitted to the ICU due to critical illness.
Past medical history:
She had a history of recurrent urinary tract stones without surgical treatment. No history of hypertension, diabetes mellitus, coronary artery disease, or drug allergy.
Physical Examination in the Emergency Department
General Condition: Confused and agitated, pale appearance, cold extremities.
Vital Signs: 39.2°C, HR 140 bpm, RR 20 breaths/min, NIBP 74/46 mmHg, oxygen therapy at 10 L/min.
Abdominal Examination: Soft abdomen, lower abdominal tenderness, no rebound tenderness, decreased bowel sounds.
Urinary System Examination: Positive bilateral costovertebral angle tenderness and suprapubic tenderness.
Initial investigations:
Physical Examination on ICU Admission
After ICU admission, the patient presented with deep, sighing respirations.
ECG monitoring showed: HR 160 bpm, RR 30 breaths/min, NIBP 80/45 mmHg.
Scenario 1：
Verbal response + hands-on demonstration
What is the most urgent next step in management?
Answer — What is the Most Urgent Next Step?
Key diagnostic points:
Decompensated septic shock: altered mental status, cold extremities, HR 160 bpm, BP 80/45 mmHg, and deep sighing respirations.
Management sequence:
PiCCO interpretation:
GEDI 620 ↓ indicates insufficient preload; CI 3.0 is borderline; SVRI 2000, ELWI 7, and PVPI 2.0 are within the normal range. These findings suggest preload deficiency, so fluid resuscitation should be continued. There is no evidence of pulmonary involvement at this stage.
Scenario 2 ：
Verbal response
After emergency treatment, the patient's current vital signs are: heart rate 130, blood pressure 90/50, SpO2 98%.
What is the patient's current diagnosis? Please briefly describe the treatment principles.
Answer-Current Diagnosis and Optimal Treatment Principles
Diagnosis:① Urosepsis / septic shock② Bilateral ureteral stones with hydronephrosis, suggesting obstructive upper urinary tract infection / acute obstructive pyelonephritis③ Lactic metabolic acidosis④ Acute hypoxemia / risk of acute respiratory failure
Treatment Principles:
1.Source control:
Urgent urology consultation, relieve obstruction by DJ stent placement or percutaneous nephrostomy. Aim to complete within 6–12 h after diagnosis. Do not wait for full hemodynamic stabilization.
2.Hemodynamic support:
Crystalloid resuscitation, initially 30 mL/kg, titrated by dynamic parameters such as GEDI and CI. Use norepinephrine as the first-line vasopressor to maintain MAP ≥65 mmHg; add vasopressin if needed.
3.Antimicrobial therapy:
Obtain blood and urine cultures, but do not delay antibiotics. Start broad-spectrum antibiotics within 1 h, mainly covering Gram-negative pathogens. De-escalate according to culture results.
Scenario 3 ：
Verbal medical orders + hands-on operation
After 2 days of treatment, the patient’s circulation has stabilized, but SpO₂ gradually decreases to 90%.
Arterial blood gas: PaO₂ 58 mmHg, PaCO₂ 42 mmHg, pH 7.38, Lac 2.5 mmol/L.
Please determine the cause of decreased oxygenation, monitor respiratory mechanics parameters, and adjust ventilator settings.
Answer--Determine the Cause of Decreased Oxygenation, Monitor Respiratory Mechanics Parameters, and Adjust Ventilator Settings
①GEDI 750 mL/m²(normal range 680–800 mL/m²), CI 3.8 L/min/m²(normal range 3.0–5.0 L/min/m²) → Cardiac preload and cardiac function are both normal, making volume overload or cardiogenic pulmonary edema less likely.
②ELWI 14 mL/kg ↑↑(normal <10 mL/kg), PVPI 4.5 ↑↑(normal <2.5–3) → Extravascular lung water is significantly increased, and this represents permeability-related pulmonary edema, rather than pulmonary edema caused by volume overload.
③SVRI 2200 dyn·s·cm⁻⁵·m²(normal range 1700–2400 dyn·s·cm⁻⁵·m²) → Systemic vascular resistance is normal, consistent with the current stable circulation.
The current FiO₂, PEEP, and ventilator mode should be reviewed and documented, and the PaO₂/FiO₂ ratio should be calculated to assess the severity of ARDS.
① Low tidal volume ventilation at 6 mL/kg predicted body weight
② Limit plateau pressure to <30 cmH₂O and driving pressure to <15 cmH₂O
③ Individualize PEEP according to oxygenation, compliance, and hemodynamics
④ If PaO₂/FiO is <150, consider prone positioning
⑤ Conservative fluid management, with restriction of fluid intake
Investigations,
provided as needed