Recently, people have paid attention to ECPR (Extracorporeal cardiopulmonary resuscitation), which uses Extracorporeal membrane oxygenation (ECMO) to resuscitate cardiac arrest patients. Several studies have reported the association between ECPR and the prognosis of cardiac arrest patients, but there was no study considering the time to the start of ECPR treatment. Dr. Yohei Okada and Professor Taku Iwami from Department of Preventive Services cooperated with the research group members based on critical care centers in Osaka, including Dr. Sho Komukai and Dr. Tetsuhisa Kitamura from Osaka University, and investigated the association between ECPR and clinical outcomes for out-of-hospital cardiac arrest patients. They considered the time to the start of ECPR using risk-set matching with a time-dependent propensity score.
In this research, they used the JAAM-OHCA registry, a prospective, multicenter, nationwide database established by the steering committee of the Japanese Association of Acute Medicine, and targeted adult patients with out-of-hospital cardiac arrest in Japan. They stratified participants depending on whether their initial cardiac rhythm was shockable or non-shockable. Using risk-set matching with a time-dependent propensity score, they compared the patients provided with ECPR treatment (ECPR group) with the patients, who did not receive ECPR treatment before or within the same minute when ECPR group got the treatment and who had the similar characteristics with ECPR group. They analyzed the data from 1,826 patients with an initial shockable rhythm (913 patients in ECPR group and 913 patients in control group) and 740 patients with an initial non-shockable rhythm (370 patients in ECPR group and 370 patients in control group). Then, they showed that the odds ratio (OR) for 30-day survival in the ECPR group increased compared to the control group (OR for 30-day survival: 1.76 [95%CI 1.38–2.25] for the patients with shockable rhythm and 5.37 [95%CI 2.53–11.43] for those with non-shockable rhythm). Furthermore, the odds ratio for favorable neurological outcomes in the ECPR group compared to the control group was 1.11 [95%CI 0.82–1.49] for those with shockable rhythm and 4.25 [95%CI 1.43–12.63] for those with non-shockable rhythm. This research showed that ECPR could be effective for patients with out-of-hospital cardiac arrest.
This thesis was published online in The Journal of Critical Care (Impact factor 15.1) on November 15th, 2023.  
Okada, Y., Komukai, S., Irisawa, T. et al. In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan. Crit Care 27, 442 (2023).
In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan – Critical Care