A national programme for on-site defibrillation by lay people in selected high risk areas: initial results.

OBJECTIVE: To report on the effectiveness of an initiative to reduce deaths from sudden cardiac arrest occurring in busy public places.

SETTING: 110 such places identified from ambulance service data as high risk sites.

PATIENTS: 172 members of the public who developed cardiac arrest at these sites between April 2000 and March 2004. 20,592 defibrillator months' use is reported, representing one automated external defibrillator (AED) use every 120 months.

INTERVENTION: 681 AEDs were installed; staff present at the sites were trained in basic life support and to use AEDs.

MAIN OUTCOME MEASURES: Initial rhythm detected by AED, restoration of spontaneous circulation, survival to hospital discharge.

RESULTS: 172 cases of cardiac arrest were treated by trained lay staff working at the site before the arrival of the emergency services during the period. A shockable rhythm was detected in 135 (78%), shocks being administered in 134 an estimated 3-5 minutes after collapse; 38 (28.3%) patients subsequently survived to hospital discharge. Spontaneous circulation was restored in five additional patients who received shocks but died later in hospital. In 37 cases no shock was initially indicated; one patient survived after subsequent treatment by paramedics, cardiopulmonary resuscitation having been given soon after collapse. Overall, irrespective of the initial rhythm, 39 patients (22.7%), were discharged alive from hospital. For witnessed arrests of presumed cardiac cause in ventricular fibrillation (an international Utstein comparator) survival was 37 of 124 (29.8%).

CONCLUSIONS: The use of AEDs by lay people at sites where cardiac arrest commonly occurs is an effective strategy to reduce deaths at these sites.