Abstract 1810: Bystander Administered AED Shock Improves Survival from Out of Hospital Cardiac Arrest in US and Canada
Introduction: The Public Access Defibrillation (PAD) trial showed that training and equipping lay volunteers to use an automated external defibrillator (AED) in community settings doubled the number of survivors after out-of-hospital cardiac arrest (OOHCA) compared to training in cardiopulmonary resuscitation (CPR) alone. The effectiveness of contemporary community-based PAD programs is unknown.
Hypotheses: Bystander defibrillation before arrival of emergency medical services (EMS) personnel improves survival.
Methods: Design-Population-based cohort study.
Setting- 11 US and Canadian urban and rural sites participating in the ROC, a prehospital emergency care trials network.
Inclusions- Individuals with non-traumatic OOHCA from 12/1/2005 to 11/30/2006, evaluated by organized EMS personnel who received attempted defibrillation before or after EMS arrival or chest compressions by EMS.
Analyses-Multivariate logistic regression assessed the association between PAD and survival to hospital discharge.
Results: Of 9897 EMS-treated OOHCA, 2991 (30.4%) received bystander CPR and 249 (2.5%) had AED placed by bystander. Overall survival to hospital discharge was 7%. Survival with bystander CPR but no AED, 8%; with AED applied by a bystander 21%; with bystander AED shock delivered, 33%; with EMS shock only, 15%. AED was applied by Lay Volunteers (32%), Police (24%), Healthcare Workers (42%), or Unknown (2%). The association between AED application and survival to hospital discharge was adjusted for age, gender, bystander CPR, public location, EMS response time and bystander witnessed status using multivariate logistic regression. After controlling for these factors, AED application was significantly associated with survival (O.R. 2.21 95% CI 1.41 – 3.47, P < .001).
Conclusions: Survival benefits demonstrated in the PAD trial can translate to improved survival in community-based programs. Extrapolating this greater survival from ROC population base (20 million) to the population of US and Canada (330 million) suggests that currently AED application by bystanders saves 412 lives per year. Contemporary PAD programs have a substantial impact on survival from cardiac arrest but impact may be limited by penetration of PAD into the community.