Abstract 181: An Analysis of Worldwide Public Access Defibrillator Usage Since October 2012. Does CPR Prior to Defibrillation Improve Survival Outcomes?

Abstract

Introduction: As outlined by the Chain of Survival, effective cardiopulmonary resuscitation (CPR) and rapid defibrillation are vital to improve survival from sudden cardiac arrest (SCA). Placement of public access defibrillators (PADs) is becoming more common in public spaces, and they are more frequently used by untrained lay-users. The objective of this analysis was to assess the effect of CPR prior to defibrillation, and the success of PAD usage in terms of first shock success and survival to hospital admission. Methods: This dataset was composed of voluntarily submitted demographic information and electronic PAD files collected from October 2012 - June 2018. Summary statistics were calculated, and proportions were determined with 95% confidence intervals (CI) where appropriate. The association between CPR prior to defibrillation and survival was investigated by fitting a logistical model with survival as the dependent variable and CPR as covariate. Results: A total of 2812 PAD events were analyzed. Mean (SD) patient age was 61 (19) years and males comprised 72.5% (1922 of 2650 events where gender was known) of the events reported. The most common locations of SCA were the home (1039, 36.9%), public (719, 25.6%) and medical facility (328, 11.7%). Median (IQR) time to PAD delivery was 5 (3, 11) minutes. Ventricular fibrillation or tachycardia was present in 1010 (35.9%) patients, and 979 received a shock, with 87.2% (95%CI [85.0%, 89.3%]) achieving first shock success. Of the 849 shockable patients for whom survival was known, 565 (66.5%, (95%CI [63.3%, 69.7%]) survived to hospital admission. Survival outcome was known for 2150 patients, and 681 (31.7%, 95%CI [29.7%, 33.69%]) survived to hospital admission. A total of 1649 (58.6%) SCAs were witnessed and 1293 (78.4%) patients received bystander CPR prior to defibrillation. Bystander CPR prior to defibrillation was significantly associated with survival to hospital admission (OR = 2.17, 95%CI [1.69, 2.81], p<0.001). Conclusion: These results suggest that CPR application prior to application of a PAD significantly increases a patient’s chances of surviving to hospital admission. This study did not assess CPR quality, but it is intuitive that good quality CPR would align with higher survival outcomes.