AS2.1-2 | Cardiopulmonary Resuscitation — Glossary

A mnemonic for reversible causes of cardiac arrest: Hypoxia, Hypovolaemia, Hypo/hyperkalaemia (metabolic), Hypothermia; Tension pneumothorax, Tamponade (cardiac), Toxins, Thromboembolism. Systematic review is mandatory during each CPR cycle.

Irregular, gasping respiratory efforts that persist as a brainstem reflex for seconds to minutes after cardiac arrest. They must not be confused with normal breathing; their presence does not exclude cardiac arrest.

A class III antiarrhythmic drug (Vaughan Williams) used in ALS for refractory VF/pVT. Adult dose: 300 mg IV after the third shock (first bolus), 150 mg after the fifth shock. Paediatric dose: 5 mg/kg IV.

Absence of any discernible electrical or mechanical cardiac activity on the ECG monitor; a non-shockable cardiac arrest rhythm. Defibrillation is not indicated.

The passive return of the sternum to its resting position between compressions, essential for venous filling of the heart. Incomplete recoil (rescuer leaning on the chest) impairs venous return and coronary perfusion pressure.

A team communication technique in which the recipient of an instruction repeats it back verbatim to confirm receipt and accuracy before acting, reducing the risk of errors during high-stress resuscitation scenarios.

Delivery of a carefully calibrated electrical shock to the myocardium intended to simultaneously depolarise the majority of cardiac cells, terminating a disorganised rhythm (VF/pVT) and allowing a normal pacemaker to re-establish coordinated activity.

The concentration of carbon dioxide in exhaled gas at the end of expiration, reflecting pulmonary blood flow and thus cardiac output during CPR. A sudden sustained rise indicates ROSC; persistently very low values (<10 mmHg) suggest inadequate compressions or very poor prognosis.

Vascular access established by inserting a rigid needle into the medullary cavity of a bone (typically the proximal tibia in adults and children), bypassing the need for peripheral venous access when veins are inaccessible during cardiac arrest. Drug pharmacokinetics are equivalent to IV.

The specialised resuscitation algorithm for neonates at birth, prioritising lung inflation (five sustained inflation breaths) as the primary intervention, with compressions at a 3:1 ratio with ventilation added only if the heart rate remains below 60/min despite effective ventilation.

A complex multisystem pathophysiological state following ROSC comprising myocardial dysfunction, brain injury, systemic ischaemia-reperfusion injury, and the persisting effects of the precipitating cause; structured post-ROSC care addresses each component.

A cardiac arrest state in which organised electrical activity is visible on the ECG but insufficient mechanical activity occurs to produce a palpable pulse. A non-shockable rhythm; management focuses on reversible causes (4Hs and 4Ts).

A regular broad-complex ventricular tachycardia producing insufficient cardiac output to generate a palpable pulse; clinically indistinguishable from VF in terms of management — defibrillation is indicated for both.

Re-establishment of sustained coordinated cardiac activity producing a palpable pulse, following cardiac arrest and resuscitation.

A post-resuscitation intervention that maintains core body temperature at 36°C (or 32–36°C per protocol) for 24 hours in unconscious survivors of cardiac arrest, reducing cerebral metabolic demand and improving neurological outcome.

One of two mechanisms by which chest compressions generate cardiac output; during chest compression, the rise in intrathoracic pressure expels blood from all intrathoracic structures, and the fall in pressure during recoil draws venous blood back into the thorax.

A chaotic, disorganised electrical rhythm originating in the ventricles characterised by rapid, irregular depolarisations with no coordinated mechanical contraction, producing cardiac arrest. It is a shockable rhythm.