The development of automated external defibrillators (AEDs) enabled the potential life-saving benefit of rapid defibrillation to be extended into locations outside traditional boundaries. Defibrillation with these devices could now be provided by minimally medically trained persons such as firefighters and police officers. The survival benefit from AED deployment by such users led to the presumption that even more rapid defibrillation might be provided by placement of AEDs in public settings where large numbers of persons are present, and where defibrillation might be accomplished by even less-trained persons, and possibly even by persons not trained at all in AED use. And thus emerged the initiative known as public access defibrillation, or PAD. In this chapter, experience with PAD is described in several different settings, fortunately with acquisition and reporting of data to permit analysis of outcomes. Experience to date is surely encouraging, yet questions remain. Pell and colleagues have raised such questions pertaining to cost-effectiveness and have recommended expansion of first-responder defibrillation such as by police or firefighters and bystander cardiopulmonary resuscitation as more defensible options to PAD.
In the PAD Trial reported by Peberdy in this chapter the low number of events is disheartening in light of the magnitude of the commitment in terms of numbers of persons trained and devices deployed, and the multiple locations in which AEDs were deployed. This observation may reflect yet another reality: the incidence of ventricular fibrillation (VF) as the presenting rhythm in out-of-hospital arrest settings is declining at an impressive rate, as reported now by several cardiac arrest investigators.