Abstract 209: Time Intervals and Rearrest After Out-of-Hospital Cardiac Arrest

Abstract

Background: Re-arrest (RA) occurs when a patient loses pulses following return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA), but the exact causes of RA are not fully understood. Time-to-treatment intervals may affect patient outcome and could be a plausible contributor to RA. Objectives: To compare emergency medical services (EMS) time intervals between cases with and without RA. We hypothesized that RA cases will have significantly longer time intervals than no-RA cases. Methods: The Institutional Review Board of the University of Pittsburgh approved this study. Cases of EMS-treated, non-traumatic OHCA from 2006 to 2011 with at least one instance of prehospital ROSC were retrospectively gathered from the Pittsburgh site of the Resuscitation Outcomes Consortium. Prehospital event times were derived from computer assisted dispatch records. We calculated time intervals to the nearest minute, including 911 call to EMS arrival, arrival to first EMS CPR, EMS CPR to ROSC, and 911 call to arrival at the emergency department (ED). RA status was determined from electronic defibrillator downloads and patient care reports. We used logistic regression to examine the association between RA and each time interval while controlling for patient demographic and clinical variables with alpha = 0.05. Results: Two-hundred and thirty-five cases were analyzed, and 79 (34%) cases had an instance of RA. Mean time intervals and patient demographics are in Table 1. The RA group had a significantly higher proportion of males and shocked cases than the non-RA group. Odds ratios for the outcome of RA by time interval are as follows: 911 to arrival: 1.09 (CI: .98 - 1.21, p = 0.10); arrival to CPR: 1.02 (CI: 0.89 - 1.19, p = 0.74); CPR to ROSC: 0.99 (CI: 0.96 - 1.02, p = 0.86); 911 to ED: 0.99 (CI: 0.96 - 1.01, p = 0.35). Conclusion: EMS time intervals for OHCA were not predictive of RA.