Abstract 68: Incidence and Outcomes of Unresolved Prehospital Rearrest in EMS-Treated Cases of Out-of-Hospital Cardiac Arrest

Abstract

Background: The phenomenon of re-arrest (RA) - loss of pulses after successful return of spontaneous circulation (ROSC) - is of interest in resuscitation research because even transient loss of pulses prior to hospital arrival may have a detrimental impact on patient outcomes. Patients who experience RA may also demonstrate specific pathology, the identification and treatment of which may lead to better outcomes. Objective: Estimate the incidence and outcomes of one manifestation of RA, unresolved prehospital-RA (UP-RA), wherein pulses are not reestablished following at least one RA prior to arrival at the emergency department (ED). Methods: Case data spanning 2006-2008 were obtained from the Resuscitation Outcomes Consortium, a multisite clinical research consortium with cardiac arrest surveillance programs in 10 sites in North America. Non-traumatic emergency medical services (EMS)-treated cases of out-of-hospital cardiac arrest (OHCA) with any instance of prehospital ROSC were included. Prehospital ROSC events, patient vital status at ED admission, survival to hospital discharge, patient demographics, and ancillary resuscitation variables were ascertained through review of paramedic-generated patient care reports (PCRs), defibrillator data downloads, and hospital records. Prehospital ROSC was defined as a detectible return of pulses resulting in an obvious suspension of CPR. UP-RA status was assigned to any case with prehospital ROSC that did not have pulses upon ED arrival. Results: Out of 18,937 cases of OHCA across all sites, there were 11,456 (60.5%) EMS-treated cases. Prehospital ROSC was found in 4,609 (40.2%) cases. Of these cases, mean(SD) age was 63.7(17), 37.1% were female, 21.5% occurred in public, 13.5% were EMS witnessed, and overall survival to hospital discharge was 28%. Vital status at ED was available for 3,116 (67.6%) cases of which UP-RA was present in 473 (15.2%). Survival was 7.8% in cases with UP-RA, compared to 33.3% in cases without, and UP-RA was directly associated with death prior to hospital discharge (OR: 6.14, CI: 4.31-8.75, p<0.001). Conclusion: When characterized as an irreversible event prior to ED arrival, incidence of RA is relatively uncommon but strongly predictive of non-survival at hospital discharge.