Emergency Medicine, Critical Care, and Anesthesiology
This domain tests the first ten minutes: prioritisation, immediate action, and recognition of physiologically lethal states before a definitive diagnosis is available.
Core rules
- ABCDE with simultaneous resuscitation. Shock categories: hypovolaemic, cardiogenic, distributive (septic, anaphylactic, neurogenic), and obstructive (tamponade, tension pneumothorax, pulmonary embolism).
- Sepsis: infection plus SOFA ≥2; measure lactate, take cultures, give broad-spectrum antibiotics within 1 h, 30 mL/kg crystalloid for hypotension or lactate ≥4, and noradrenaline targeting MAP ≥65 mmHg.
- Anaphylaxis: intramuscular adrenaline 0.5 mg (1:1000) into the lateral thigh, repeated every 5 minutes; fluids and adjuncts must never delay adrenaline. Rash may be absent.
- Airway: assess Mallampati, mouth opening, and neck mobility, preoxygenate, and plan for difficulty before induction.
- Malignant hyperthermia: triggered by volatile agents and suxamethonium; rising end-tidal CO2, masseter spasm, hyperthermia, and acidosis. Stop triggers, hyperventilate with 100% oxygen, give dantrolene 2.5 mg/kg, and cool.
- Local anaesthetic systemic toxicity: 20% lipid emulsion 1.5 mL/kg bolus.
- ARDS (Berlin): lung-protective ventilation at 6 mL/kg predicted body weight, adequate PEEP, prone positioning when PaO2/FiO2 <150.
Worked example
A 20-year-old under sevoflurane develops rising end-tidal CO2 despite increased ventilation, masseter rigidity, tachycardia, and a temperature of 39.5°C. Reasoning: malignant hyperthermia. Stop the volatile and suxamethonium, hyperventilate with 100% oxygen, give dantrolene, actively cool, and monitor potassium, creatine kinase, and urine output for rhabdomyolysis.
Traps
- Giving fluid boluses in cardiogenic shock without inotropes or vasopressors.
- Waiting for a chest radiograph before decompressing a tension pneumothorax.
- Attributing post-induction hypotension to hypovolaemia when it is anaphylaxis.