Abstract 271: The Time Dependence Of The Effect Of Extracorporeal Cpr For Out-of-hospital Cardiac Arrest Patients

Abstract

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) has been considered as a rescue therapy for refractory cardiac arrest patients. However, little is known about who is refractory to conventional CPR and when to judge the initiation of ECPR. Method: We performed a secondary analysis of the nationwide hospital-based prospective observational study (The JAAM-OHCA registry) in Japan. This study included adult OHCA patients aged ≥18 years who had an initial shockable rhythm between June, 2014 and December, 2019. We classified the included patients into the ECPR group or the conventional CPR group based on whether to receive ECPR or not. Low flow duration (LFD) was defined as the time from call to the initiation of ECPR or to the time of return of spontaneous circulation or termination of resuscitation. The primary outcome was 1-month survival with favorable neurological outcomes defined by cerebral performance category 1 or 2. We visually described the nonlinear relationship between LFD and the predictive probability of favorable neurological outcome using a restricted cubic spline by each group. Results: Of 57,754 patients registered in the JAAM-OHCA registry, 3807 patients were included in analyses (ECPR group, n = 865 and Conventional CPR group, n = 2942). In both groups, shorter LFD was associated with favorable neurological outcome. For first 30 minutes, the overall proportion of favorable neurological was higher in the Conventional CPR group, but due to the rapid decrease in Conventional CPR, it dropped down to almost the same probability before 20 min as that of shortest LFD around 25 min in the ECPR group. After that, the probability of favorable neurological outcome was constantly higher in the ECPR group. Conclusion: The judgement of refractory cardiac arrests and decision for ECPR should be delivered before 20 min from call to maximize the probability of favorable neurological outcome for those with an initial shockable rhythm.