Abstract 246: Incidence and Outcomes of Rearrest Following Out-of-Hospital Cardiac Arrest

Abstract

Background: Rearrest (RA) occurs when a patient experiences cardiac arrest after successfully achieving return of spontaneous circulation (ROSC). The incidence and outcomes of RA following out-of-hospital cardiac arrest (OHCA) have been estimated in limited local studies. We sought to investigate the incidence and outcomes of RA over a broad geographic area. Methods: This retrospective study was approved by the University of Pittsburgh Institutional Review Board. We obtained case data from EMS-treated, non-traumatic OHCA from the Resuscitation Outcomes Consortium, a multi-site clinical research network conducting population level surveillance of OHCA in 11 cities in the US and Canada. The study cohort comprised all OHCA cases surveilled between 2006 and 2008 at ROC sites and having prehospital ROSC. We used three methods to ascertain RA incidence among these cases: direct signal analysis, indirect cardiopulmonary resuscitation (CPR) process analysis, and emergency department arrival vital status. RA incidence was estimated as the proportion of cases with ROSC that experience RA. Regional RA estimates were compared with the Chi-Squared test. Multivariable logistic regression was used to assess the relationship between RA and survival to hospital discharge. Results: Out of 18,937 cases of EMS-assessed OHCA captured between 2006 and 2008, 11,456 (60.5%) cases were treated by EMS and 4,396 (38.4%) had prehospital ROSC. Of these, sufficient data were available for RA ascertainment in 3,253 cases, with 568 (17.5%) experiencing RA. Regional RA incidence varied significantly from 10.2% to 21.2% (p < 0.001). RA was significantly inversely associated with survival (OR: 0.19, 95%CI: 0.14 - 0.26). Conclusions: In this geographically broad and inferentially conservative analysis, RA occurred on average in 1 of every 6 successfully resuscitated patients, though incidence varied significantly across 10 sites in North America. RA was found to be inversely associated with survival to hospital discharge.