Perioperative cardiac arrest occurs in about 1 in 3,000 anaesthetics. The majority occur in older, frailer patients (1 in 1,200), and in high-risk or emergency surgery. The cause may be the result of underlying medical disease – usually cardiac, secondary to surgery – usually due to haemorrhage or secondary to an anaesthetic cause – usually due to hypoxia and hypercapnia, typically resulting from airway problems.

The Resuscitation Council has issued algorithms to guide management of basic and advanced life support in both adults and children. Advanced life support secures the airway and supports the circulation using drugs with the aim of the return of spontaneous circulation. Two main types of arrhythmia occur in a cardiac arrest:

• Non-shockable: pulseless electrical activity (PEA) – a QRS complex without a palpable pulse and asystole

• Shockable: ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT)

Potentially reversible causes of cardiac arrest should be actively sought and treated. There are special circumstances after 28 weeks of pregnancy which require attention and are described. A traumatic cardiac arrest resuscitation algorithm is discussed.