Approaches to modern management of cardiac arrest

The major determinant in survival of patients with out-of-hospital ventricular fibrillation (VF) is the delay to defibrillation. Since the first report of survival from out-of-hospital VF1 there has been a natural progression to make defibrillation more accessible. This trend has been aided by the development of automatic external defibrillators. The time delay to defibrillation can be reduced by five minutes if performed by a first responder to the cardiac arrest rather than by the usual paramedic service.2 In a review of five controlled trials in which emergency medical technicians were taught to defibrillate, odds ratios for improved survival ranged from 3.3 to 6.9.3 Emergency medical technicians were taught to recognise cardiac arrhythmias and to operate a manual defibrillator in four trials; an automatic external defibrillator was used in the remaining trial. The validity of emergency medical technicians using automatic external defibrillators has also been tested in controlled trials.4-6 There were no significant differences in hospital admission or discharge rates for patients with cardiac arrest treated by emergency medical technicians (trained to recognise VF) using either a manual defibrillator or an automatic external defibrillator. However, the delay to the first shock was significantly shorter in the automatic external defibrillator group. Successful use of automatic external defibrillators by emergency medical technicians has raised the possibility of these devices being used by minimally trained individuals. Automatic external defibrillators have already been used successfully by family members of survivors of out-of-hospital cardiac arrest7 and by security staff at large public gatherings.8 The use of these devices by the lay public could reduce further the time to defibrillation. Several issues concerning the widespread dissemination of automatic external defibrillators for public use need to be discussed. It is essential that automatic external defibrillators have a very high specificity for shockable …