Abstract 215: First Shock Success Rates Across Waveforms and Energy Levels in Adult Cardiac Arrest: A Systematic Review and Meta-analysis

Abstract

Objectives: Current guidelines advise a single biphasic shock followed by chest compressions; however, it is unclear if this applies to all waveforms and energy levels. We conducted a systematic review and meta-analysis of the literature to determine the comparative success rates for single-shock defibrillation across waveforms evaluated in out-of-hospital cardiac arrest patients presenting in Ventricular Fibrillation. Methods: A comprehensive search strategy was used across Embase, Medline, Cochrane libraries, dissertation abstracts and clinicaltrials.gov, and unpublished data was sought. Two investigators independently reviewed titles, abstracts and full texts in a hierarchical manner for study eligibility with a quadratic kappa score at each level. Two authors abstracted data independently, and the quality of the articles was assessed using the Jadad scale. Outcomes were termination of fibrillation to any rhythm (TOF), return of organized rhythm (ROOR) and return of spontaneous circulation (ROSC). Results: A total of 3,281 potentially relevant citations were identified and of these 7 RCTs were selected with Kappa values of titles 0.53, abstract 0.71, and article 0.94. Mean quality scores varied from 1-2.5/3. First-biphasic shock success (pooled mean) for TOF were similar: Biphasic Truncated Exponential (BTE) 200J 90.5%, BTE 150J 89.9%, Rectilinear Biphasic (RLB) 120J 84.9% but were lower and divergent for both ROOR BTE 200J 43%, BTE 150J 38%, RLB 23% and ROSC; BTE 200J 39%, BTE 150J 78%, RLB 46%. Median time to first shock (min) varied across trials (5.1 BTE 200/150J, 10.4 RLB) and may contribute to observed differences. Conclusion: First shock success rates as measured by the industry standard of TOF do not significantly differ across biphasic waveforms and energy levels.