A link between emergency dispatch and public access AEDs: potential implications for early defibrillation

Background: Public access defibrillation can improve survival but is involved in only a small fraction of out-of-hospital cardiac arrest. One approach to increase involvement is to couple emergency dispatch with mapping technology to identify public access automated external defibrillators (AEDs) that are on-site or nearby.

Methods: We conducted a retrospective observational cohort investigation of out-of-hospital cardiac arrest who received dispatch by a community dispatch center between January 1, 2007 and December 31, 2009. The dispatch system is linked to the public access AED registry. The technology enables dispatcher alert of an on-site AED and the potential to alert for an AED within 0.1 mile. We report the observed and potential frequency of AED involvement.

Results: Of the 763 cardiac arrest events, 4.2% (32/763) had an AED applied by non-EMS persons, 1.3% (10/763) by police and 2.9% (22/763) in layperson settings. Among the remaining 731 where an AED was not applied, 8.1% (59/731) had an AED identified through dispatch; 18 with an AED on-site and an additional 41 with an AED within 0.1 mile. When restricting to ventricular fibrillation arrests, 8.9% (16/179) had an AED applied by non-EMS persons, 2.8% (5/179) by police and 6.1% (11/179) in layperson settings. Among the remaining 163 where an AED was not applied, 11.7% (19/163) had an AED identified through dispatch; 9 with an AED on-site and an additional 10 with an AED within 0.1 mile.

Conclusion: A working link between emergency dispatch and an AED registry may provide an opportunity to improve resuscitation.