Impact of Low-Flow Duration on Favorable Neurological Outcomes of Extracorporeal Cardiopulmonary Resuscitation After Out-of-Hospital Cardiac Arrest
Authors: Tasuku Matsuyama, Taro Irisawa, Tomoki Yamada, Koichi Hayakawa, Kazuhisa Yoshiya, Kazuo Noguchi, Tetsuro Nishimura, Takuya Ishibe, Yoshiki Yagi, Takeyuki Kiguchi, Masafumi Kishimoto, Hiroshi Shintani, Yasuyuki Hayashi, Taku Sogabe, Takaya Morooka, Haruko Sakamoto, Keitaro Suzuki, Fumiko Nakamura, Norihiro Nishioka, Yohei Okada, Satoshi Matsui, Junya Sado, Takeshi Shimazu, Bon Ohta, Taku Iwami, Tetsuhisa Kitamura
Journal: Circulation (2020)

xtracorporeal cardiopulmonary resuscitation (ECPR) is expected to benefit the rescue of selected patients, particularly those who are refractory to conventional cardiopulmonary resuscitation (CPR). 1 Considering its invasive procedure and considerable resources, establishing a helpful criterion for initiating ECPR remains crucial.Low-flow duration (LFD) is one of the most common criteria to identify candidates for ECPR. 1 However, the association between LFD and favorable neurological outcome has not been sufficiently investigated in out-of-hospital cardiac arrests (OHCAs).This study aimed to assess (1) whether LFD was associated with 1-month survival or favorable neurological outcome after ECPR and (2) the interplay between the documented cardiac rhythms and LFD on neurological outcomes of ECPR.The CRITICAL study (Comprehensive Registry of Intensive Cares for OHCA Survival) was a multicenter, prospective cohort study of patients with OHCA in Osaka Prefecture, Japan, involving 14 institutions. 2This secondary analysis of the CRITI-CAL study included adult patients ≥18 years of age with OHCA who received ECPR before the return of spontaneous circulation from July 1, 2012, to December 31, 2016.LFD was defined as the time interval from initiation of any CPR (bystander CPR or CPR by emergency medical services personnel) to the initiation of ECPR.The information on the initiation of bystander CPR was obtained by emergency medical services interview with the bystanders before leaving the scene.LFD was classified into the following tertiles: short (23-45 minutes), middle (46-57 minutes), and long (58-117 minutes).The primary outcome was 1-month survival with favorable neurological outcome defined by Cerebral Performance Category 1 or 2. The secondary outcome was 1-month survival.First, we visually described the nonlinear relationship between LFD and the estimated probability of favorable neurological outcome using restricted cubic spline in the univariable logistic regression model based on prehospital and in-hospital first documented cardiac rhythm (shockableshockable [ie, sustained shockable rhythm] or other).Second, to investigate the effect of LFD on each outcome, we applied univariable and multivariable logistic regression analyses, adjusting for age (continuous), sex, cause of arrest (cardiac or noncardiac), and prehospital and in-hospital first documented rhythm (sustained shockable rhythm or other).This study was approved by the ethics committees of the participating hospitals.During the study period, 9822 patients with OHCA were registered, and 256 patients were eligible for our analysis.The proportion of favorable neurological outcome was 22.0% (22 of 100), 17.1% (14 of 82), and 6.8% (5 of 74) in the short, middle, and long groups, respectively.Although the probability of favorable neurological outcome decreased as LFD increased, those with sustained shockable rhythm had a higher chance of achieving favorable neurological outcome than those with other rhythms when they received ECPR at the