Abstract 135: The Association of Preshock Pause and Survival from Out-of-Hospital Cardiac Arrest
Objective: Preshock pause (PSP_time from last chest compression [CC] to defibrillation) is believed to be an important component of CPR quality, but the relationship between PSP and survival is unknown. We sought to determine if a dedicated intervention to improve prehospital CPR quality and minimize PSPs would result in a shortened preshock interval and improve survival from out-of-hospital cardiac arrest (OHCA).
Methods: Data were extracted from prehospital care reports and defibrillators (E Series, ZOLL) of 2 EMS agencies (combined population-500,000) participating in a CPR quality improvement program. Consecutive non-traumatic adult OHCA of presumed cardiac etiology were included. Phase 1 (P1): 19 months of baseline data with real-time audiovisual feedback (RTAVF) disabled (9/08-3/10).
Interventions: 1) Scenario-based training of ∼450 EMTs, 2) RTAVF enabled, 3) activation of “Charging During Compressions” feature, 4) EMT post-code debriefings. Phase 2 (P2):16 months immediately following implementation (5/10-9/11). Analysis: Univariate logistic regression, Kruskal-Wallis, and chi-squared.
Results: 192 OHCA patients (P1-95, P2-97) who had resuscitation initiated in the field and at least one shock, regardless of initial rhythm, were included. Mean age 64 years (SD ± 15) with 70% males. Median number of shocks/case in both P1 and P2 was 3 (IQR 1-4 P1, 1-5 P2, p=0.9). The median PSP shortened significantly: P1: 24.0 sec (15.6-32.0); P2: 14.5 sec (9.2-20.3), p<0.001. For patients treated with shocks, 18% survived in P1 vs. 29% in P2, p=0.07. The median PSP in survivors was significantly shorter than for non-survivors (13.7 sec [8.5-21.7] vs. 19.4 sec [13.0-30.4], p=0.002). Survival to discharge was greater when PSP was less than 15 seconds (37% vs. 19% for 15-29 sec, 11% for 30-44 sec, 8% for >45 sec, p=0.009). Univariate logistic regression revealed that PSP was a significant predictor of survival (0.78 OR/5 sec, 0.66-0.93, p=0.006). For each 5 second increase in PSP, the odds of survival decreased by 22%.
Conclusion: The combination of RTAVF and scenario-based training were associated with a significant shortening of the PSP during prehospital resuscitation. PSP was a significant predictor of survival by univariate analysis.
- © 2012 by American Heart Association, Inc.