Abstract 128: Compressions During Defibrillator Charging Shortens Shock Pause Duration and Improves Chest Compression Fraction During Shockable Out of Hospital Cardiac Arrest
BACKGROUND: Previous studies have demonstrated significant relationships between shock pause duration and survival to hospital discharge from out-of hospital (OHCA) shockable cardiac arrest. Compressions during defibrillator charging (CDC) has been proposed as a technique to shorten shock pause duration.
OBJECTIVE: We sought to determine the impact of CDC on shock pause duration and CPR quality measures in shockable OHCA.
METHODS: We performed a retrospective review of all treated adult OHCA occurring over a one year period beginning August 1, 2011 after training EMS agencies in CDC. We included OHCA patients with an initial shockable rhythm and available CPR process and shock pause data for the first three shocks of the resuscitation. CDC by EMS personnel was confirmed by review of impedance channel measures. We evaluated the impact of CDC on shock pause duration as the primary outcome measure. Secondary outcome measures were the impact of CDC on CPR quality measures (chest compression fraction, compression rate and depth).
RESULTS: Among 674 treated OHCA 158 (23.4%) presented in a shockable rhythm of which 129 (81.6%) met study inclusion criteria. Seventy (54.2%) received CDC. There was no significant difference between the CDC and no CDC group with respect to Utstein variables. Mean pre-shock pause (24.3 vs. 8.7 sec; Δ 15.6; 95% CI: 12.7, 18.5), post-shock pause (6.0 vs. 3.8 sec; Δ 2.2; 95% CI: 0.8, 3.5), and peri-shock pause (30.3 vs. 12.3 sec; Δ 18.0; 95% CI: 14.7, 21.3) were all significantly lower for those who received CDC. Mean chest compression fraction was significantly greater (0.77 vs. 0.70, [[Unable to Display Character: ▵]] 0.07; 95% CI: 0.03, 0.11) with CDC. No significant difference was noted in compression rate or depth with CDC. Clinical outcomes did not differ between the two approaches (return of spontaneous circulation 62% vs. 62% p=0.98, survival 25.4% vs. 27.1% p=0.82), although the study was not powered to detect clinical outcome differences.
CONCLUSIONS: Compressions during defibrillator charging shortens shock pause duration and improves chest compression fraction in shockable OHCA. Given the impact on shock pause duration, further study with a larger sample size is required to determine the impact of this technique on clinical outcomes from shockable OHCA.
- © 2013 by American Heart Association, Inc.