Neurologic outcomes after extracorporeal membrane oxygenation assisted CPR for resuscitation of out-of-hospital cardiac arrest patients: A systematic review.

Abstract

Extracorporeal membrane oxygenation-assisted CPR (ECPR) is an evolving adjunct for resuscitation of OHCA patients. The primary objective of this systematic review was to assess survival-to-hospital discharge with good neurologic recovery after OHCA among patients treated with ECPR compared to conventional CPR (CCPR). A systematic search of MEDLINE^® and EMBASE^® electronic databases was performed from inception until July 2016 to identify studies reporting ECPR use in adults with OHCA and survival outcomes. Of the 1512 citations identified, 75 studies met our inclusion criteria (63 case series and 12 cohort studies). Among case series, 0 to 71.4% of patients treated with ECPR survived to discharge with a good neurologic outcome. Subgroup analysis of the cohort studies demonstrated survival-to-hospital discharge with good neurologic recovery in the ECPR group ranging from 8.3 to 41.6% compared to 1.5 to 9.1% in the CCPR group. Five cohort studies adjusted for confounders, 3 of which demonstrated significantly increased adjusted odds ratios of survival among the ECPR-treated patients. Due to significant heterogeneity (I² = 63%, p = 0.03), pooling of outcomes and a meta-analysis were not conducted. Although a trend towards improved survival with good neurologic outcome was reported in controlled, low-risk of bias cohort studies, a preponderance of low quality evidence may ascribe an optimistic effect size of ECPR on survival among OHCA patients. Our confidence in a clinically relevant difference in outcomes compared to current standards of care for OHCA remains weak. In this state of equipoise, high quality RCT data is urgently needed.