Critical Care and Emergency Medicine
Critical care questions ask you to prioritise in the first minutes: airway, perfusion, glucose, and a working diagnosis. The examiner looks for recognition of shock type, appropriate fluid and vasopressor use, and safe ventilation.
Shock and resuscitation
- Classify shock: hypovolaemic, cardiogenic, distributive (septic, anaphylactic, neurogenic), and obstructive (tamponade, tension pneumothorax, massive pulmonary embolism). Bedside ultrasound, lactate, and central venous oxygen saturation refine the picture.
- Norepinephrine is first line in septic shock; give 30 mL/kg crystalloid early, then reassess with dynamic measures rather than static pressure alone.
- Anaphylaxis: intramuscular adrenaline 0.5 mg into the anterolateral thigh, repeated every five minutes, with fluids and airway readiness. Antihistamines and steroids are adjuncts only.
- Tension pneumothorax is a clinical diagnosis: decompress immediately, then place a chest drain.
Ventilation and oxygenation
- Acute respiratory distress syndrome (Berlin definition): onset within a week, bilateral opacities not explained by cardiac failure, and a PaO2/FiO2 ratio of 300 or less on positive end-expiratory pressure of at least 5 cmH2O.
- Use lung-protective ventilation with tidal volume 6 mL/kg predicted body weight and plateau pressure below 30 cmH2O. Prone positioning for a PaO2/FiO2 ratio below 150.
- Post-cardiac-arrest care: targeted temperature control, avoid hyperoxia and hypotension, treat the cause, and delay prognostication.
Common emergencies
- Rapid sequence intubation: pre-oxygenate, prepare suction and drugs, choose induction and paralysis agents by haemodynamics, and confirm with capnography.
- Upper gastrointestinal bleed, diabetic ketoacidosis, and status epilepticus follow protocolised pathways that should be quoted accurately.
Worked example
A 60-year-old with pneumonia is hypotensive at 78/40, lactate 5.2 mmol/L, warm peripheries, and clear lungs. This is distributive septic shock. Give 30 mL/kg crystalloid in boluses with reassessment, start norepinephrine early to reach a mean arterial pressure of 65 mmHg, obtain cultures and give antibiotics within one hour, and use bedside ultrasound to check cardiac function before further fluid.
Traps
Giving adrenaline subcutaneously rather than intramuscularly in anaphylaxis; using high tidal volumes in ARDS; waiting for a chest radiograph in tension pneumothorax; and giving bolus fluid in cardiogenic shock without assessing the heart.