Impact of rapid response car system on ECMO in out-of-hospital cardiac arrest: A retrospective cohort study

INTRODUCTION: Extracorporeal life support (ECLS) has been reported to be more effective than conventional cardiopulmonary resuscitation (CPR). In ECLS, a shorter time from arrival to implantation of extracorporeal membrane oxygenation (ECMO; door-to-ECMO) time was predicted to be associated with better survival rates. This study aimed to examine the impact of the physician-based emergency medical services (P-EMS) using a rapid response car (RRC) on door-to-ECMO time in patients with out-of-hospital cardiac arrest (OHCA). METHODS: In this retrospective cohort study, adult patients with OHCA who were admitted to a Japanese tertiary care hospital from April 2012 to December 2016 and underwent venoarterial ECMO were included. Patients were either transferred by emergency medical service (EMS only group) or RRC (RRC group). Primary outcome was door-to-ECMO time. Wilcoxon rank-sum test was used to compare the outcome between the two groups. RESULTS: A total of 34 patients were included in this study, and outcome data were available for all patients. The door-to-ECMO time was significantly shorter in the RRC group than in the EMS only group (median, 23min vs. 36min; P=0.006). Additionally, the RRC was also associated with earlier successful intubation and intravenous adrenaline administration. CONCLUSION: The physician-based RRC system was associated with a shorter door-to-ECMO time and successful advanced procedures in prehospital settings. Combination of the RRC system with ECLS may lead to better outcomes in patients with OHCA.