Public Access Defibrillation (PAD) Community Trial

Objectives:

The Public Access Defibrillation (PAD) Community Trial sought to evaluate broad implementation of Public Access Defibrillators (PAD) in urban community units. Survival to hospital discharge of patients with out-of-hospital cardiac arrest was the main outcome measure. Survival was compared in community units (e.g., apartment or office buildings, gated communities, sports venues, senior centers, shopping malls) served by non-medical responders trained in CPR and use of automated external defibrillators (AEDs), to units receiving the traditional optimum community standard of care (i.e., rescuers trained to recognize a cardiac emergency, call 911, and initiate CPR).

Background:

Sudden out-of-hospital cardiac arrest (OOH-CA) remains a significant cause of death, in spite of recent declines in overall mortality from cardiovascular disease. Existing methods of emergency resuscitation are inadequate due to time delays inherent in transporting trained responders with defibrillation capabilities to the side of the OOH-CA victim.

Existing Emergency Medical Services (EMS) systems typically combine paramedic Emergency Medical Technician (EMT) services with some level of community involvement, such as bystander cardiopulmonary resuscitation (CPR) training. Some communities include automated external defibrillators (AEDs) at isolated sites or in mobile police or fire vehicles. Such an approach typically varies in effectiveness, with an incremental improvement in effectiveness seen in communities that organize and integrate services with the existing EMS system. However, optimal improvement in survival from sudden OOH-CA may require a program that utilizes volunteer non-medical responders (who may not have a traditional duty to respond to an emergency) trained to use AEDs.

Subjects:

The PAD trial was a prospective, randomized community based trial. More than 19,000 volunteer responders from 993 community units in 24 North American regions participated. The two study arms had similar unit and volunteer characteristics. Patients with treated out-of-hospital cardiac arrest in the two groups were similar in age (mean: 69.8 years), proportion of men (67 perecnt), rate of cardiac arrest in a public location (70 percent), and rate of witnessed cardiac arrest (72 percent).

Conclusions:

Community units with volunteers trained in CPR and AEDs had significantly more patients surviving to hospital discharge than units with volunteers trained to use CPR only. There were 30 survivors among 128 definite cardiac arrests in the CPR+AED units and 15 survivors among 107 definite cardiac arrests in the CPR only units (p = 0.03). Serious adverse effects were rarely reported. No volunteers received inadvertent shocks, and no patients were shocked unnecessarily. AED maintenance problems were infrequent. A few participating volunteers reported severe stress related to responding to emergency situations. Although residential complexes represented 16% of the units and 29% of the treatable cardiac arrests, only 5% of the survivors were from residential complexes. Such information should be helpful for individual facilities that are considering implementing PAD programs. (NEJM 2004; 351:637-46).