Abstract 311: Defibrillation in Public Places. Who is Shocking the Patients?

Abstract

Background: In 2003, survival from Out of Hospital Cardiac Arrest (OHCA) was 2,5 % in Stockholm county. To increase survival, a first responder system was implemented in 2005 in parallel with a structured Public Access Defibrillation (PAD) program. In addition, the number of “wild” public Automated External Defibrillators (AEDs) has rapidly increased over time. Aim: To evaluate the impact on survival from three different defibrillation strategies (EMS, first responders and PAD) in OHCA patients available for PAD in Stockholm County, Sweden. Methods: All witnessed cases of OHCA outside home of cardiac origin with shockable rhythm in Stockholm County 2006-2012 were considered subjects for PAD and were included in the study. 60 high incidence sites were initially selected for the PAD program, and security officers and lay responders were trained to respond to “on site” emergencies. The number of sites in the PAD program increased to 120 at the end of the study. 35 fire stations throughout the county were available for simultaneously dispatch to suspected OHCAs. By approximations based on wholesale numbers, around 1000 public AEDs were present outside the PAD program. Results: 469 OHCA cases were included in the study. Out of these, 66 % (n=311) were defibrillated by the EMS, 16% (n=77) by a first responder and in 17% (n=81) the first shock was delivered by a public AED. In 33% (n=27) the public AED was a part of the PAD program. Survival to 1-month was 33 % in cases were defibrillation was performed by the EMS (n=103), 33% if defibrillation was performed by a first responder (n=25) and 66 % (n=55) if a public AED was used. Defibrillation by EMS and first responders in patients suitable for PAD decreased over time[[Unable to Display Character: ]]from 93% to 73 %. Concurrently, defibrillation by public AEDs increased from 7% to 27% during the study period. Conclusion: [[Unable to Display Character: ]]Public AEDs significantly contributes to survival in OHCAs suitable for PAD in Stockholm County, demonstrated by a 1-month survival of 66%. In this patient population, a public AED is used in 30% of all cases and with increased use of AEDs, PAD might challenge the potential gain from EMS and first responder systems.