Intensive Care and Critical Care Medicine
Core topics
Critical care questions test recognition and early management of shock, sepsis, respiratory failure, and organ support. Know the types of shock (hypovolaemic, cardiogenic, distributive/septic, obstructive) and their haemodynamic signatures. Understand sepsis bundles (fluids, antibiotics, source control, vasopressors), the Surviving Sepsis approach, and that norepinephrine is first-line vasopressor. Respiratory: ARDS definition (acute onset, bilateral infiltrates, PaO2/FiO2 ratio, not cardiac), lung-protective ventilation (tidal volume ~6 mL/kg predicted body weight, plateau pressure limits), and prone positioning. Renal: AKI staging, indications for dialysis. Neuro: GCS, sedation holds, delirium. Nutrition and glucose control principles.
Traps
- Confusing ARDS with cardiogenic pulmonary oedema - the stem often gives a normal or low wedge pressure.
- Forgetting that permissive hypercapnia is acceptable in lung-protective ventilation but not in raised intracranial pressure.
- Assuming a normal blood pressure excludes shock - compensated shock can have normal BP with high lactate.
- Missing that vasopressors should follow adequate fluid resuscitation, not replace it.
Rule of thumb
For shock, follow the sequence: recognise (lactate, perfusion), resuscitate (fluids), then support (vasopressors, ventilation) and treat the cause (source control).
Worked example
A septic patient has MAP 60 with lactate 4 and warm peripheries. This is distributive shock: give fluids, start norepinephrine, obtain cultures and antibiotics, and arrange source control.