title: Cardiac arrest in the out-of-hospital setting: when to halt resuscitation.
abstract: In out-of-hospital settings, when is it reasonable to halt attempts to resuscitate a victim of sudden cardiac arrest? To answer these questions, we reviewed the relevant literature using the standard Prescrire methodology. Retrospective studies of several thousand cases suggest that the chances of survival depend on how rapidly survival measures are implemented, how quickly medical help arrives, the type of cardiac arrhythmia, early defibrillation, and return of spontaneous circulation. The chances of survival without neurological sequelae are virtually nil when medical assistance does not arrive within 8 minutes and when the patient is already in asystole. Unless spontaneous circulation resumes after 30 minutes of medical resuscitation, the survival chances are also considered to be nil, except in case of hypothermia or persistent ventricular fibrillation (or tachycardia): it is then reasonable to cease resuscitation attempts. However, it may be appropriate to continue resuscitation procedures beyond 30 minutes in order to help relatives come to terms with the patient's death. In practice, when sudden cardiac arrest occurs in the community, those present must implement a chain of survival in order to optimise the patient's chances of survival. Physicians called to the scene must assess the victim's chances of survival in order to decide when to halt resuscitation attempts.
mesh_terms: D016887:Cardiopulmonary Resuscitation; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D013997:Time Factors