Abstract 9114: Impact of the Number of Prehospital Defibrillation Attempts on Neurologically Intact Survival in Patients With Out-of-Hospital Cardiac Arrest and Shockable Rhythm

Abstract

Background: Early return of spontaneous circulation (ROSC) leads to survival with a favorable neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). For the early ROSC, defibrillation plays a crucial role for OHCA with shockable rhythm. However, little is known about the relation between the number of prehospital defibrillation attempts or etiology of OHCA and neurologically intact survival. Methods: Using a nationwide OHCA registry database from 2005 to 2017 in Japan, a cohort of 1,527,447 patients with OHCA were retrospectively analyzed. We included the patients of witnessed OHCAs with initial shockable rhythm. The relation between early ROSC, defined as prehospital ROSC achieved with defibrillation ≤3 times without adrenaline, and a neurologically intact survival rate (cerebral performance category score of 1 or 2 at 1 month) was evaluated. We also analyzed factors related to the successful early ROSC, including etiology of OHCA. Results: A total of 75,342 patients were included. Among patients with OHCA and prehospital ROSC, neurologically intact survival rates were better in patients who achieved early ROSC than their counterpart (62% vs. 36%, p<0.001). Success in early ROSC was an independent predictor of neurologically intact survival after adjustment of multiple cofounders (Table). Multivariate analysis showed cerebral vascular disease as an etiology of OHCA was a predictor of early ROSC (odds ratio 1.15, 95% confidence interval 1.03-1.29, p=0.02), but was significantly associated with a poor neurologic outcome at 1 month (Table). Conclusions: Success in early ROSC was associated with neurologically intact survival in patients with OHCA and initial shockable rhythm. Patients with OHCA due to cerebral vascular disease were likely to be resuscitated from cardiac arrest by defibrillations but had a poor neurologic outcome.