Emergency Medicine
Emergency questions are structured around resuscitation sequences and antidote recall. The exam expects you to state the first action, not a differential list.
Cardiac arrest
Ventricular fibrillation and pulseless ventricular tachycardia are shockable: defibrillate, then CPR, then adrenaline and amiodarone. Asystole and pulseless electrical activity are non-shockable: CPR and adrenaline, with a search for reversible causes (hypoxia, hypovolaemia, hypothermia, hyper/hypokalaemia, tamponade, toxins, thrombosis, tension pneumothorax).
Toxicology
- Paracetamol: use the Rumack-Matthew nomogram from 4 hours post-ingestion; give N-acetylcysteine.
- Salicylate: alkaline diuresis with sodium bicarbonate; dialysis for severe toxicity.
- Opioid: naloxone titrated to respiratory effort, not full consciousness.
- Carbon monoxide: 100% oxygen; hyperbaric therapy for severe poisoning or pregnancy.
- Metformin-associated lactic acidosis: urgent dialysis.
Shock
The first branch point is whether the patient is cold or warm, then whether the cause is distributive, cardiogenic or obstructive. Bedside ultrasound accelerates this.
Worked example
A patient presents 6 hours after ingesting 20 g of paracetamol with a level above the treatment line. Give N-acetylcysteine without waiting for transaminases; the antidote is most effective within 8 hours of ingestion.
Traps that cost marks
- Shocking asystole.
- Giving naloxone as a fixed large bolus and precipitating withdrawal and agitation.
- Waiting for liver enzymes before starting N-acetylcysteine.