Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest: a scoping review

Abstract

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging concept in cardiac arrest and cardiopulmonary resuscitation. Recent research has documented a significant improvement in favorable outcomes, notable survival to discharge, and neurologically intact survival.

Objectives: The present study undertakes a scoping review to summarize the available evidence by assessing the use of ECPR, compared with no ECPR or the standard of care, for adult patients who sustain cardiac arrest in any setting, in studies which record survival and neurologic outcomes.

Methods: This review followed the PRISMA extension for scoping reviews (PRISMA-ScR) guidelines. Four online databases were used to identify papers published from database inception to July 12, 2020. We selected 23 observational studies from Asia, Europe, and North America that used survival to discharge or neurologically intact survival as a primary or secondary endpoint variable in patients with cardiac arrest refractory to standard treatment.

Results: Twenty-three observational studies were included in the review. Eleven studies were of out-of-hospital cardiac arrest, 7 studies were of in-hospital cardiac arrest, and 5 studies included mixed populations. Ten studies reported long-term favorable neurological outcomes (ie, Cerebral Performance Category score of 1 - 2 at 3 months [n = 3], 6 months [n = 3], and 1 year [n = 4]), of which only 4 had statistical significance at 5% significance levels. Current knowledge is mostly drawn from single-center observations, with most of the evidence coming from case series and cohort studies, hence is prone to publication bias. No randomized control trials were included.

Conclusions: This scoping review highlights the need for high-quality studies to increase the level of evidence and reduce knowledge gaps to change the paradigm of care for patients with shock-refractory cardiac arrest.

Keywords: ECPR; cardiac arrest; extracorporeal cardiopulmonary resuscitation; extracorporeal life support; extracorporeal membrane oxygenation; refractory ventricular fibrillation; resuscitation.

FIGURE 1

Preferred reporting items for systematic reviews and meta‐analyses flow diagram for the scoping review process—clinical search strategy. From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group. Preferred reporting items for systematic reviews and meta‐analyses: The PRISMA Statement. PLoS Med 2009;6:e1000097

FIGURE 2

Forest plot of long‐term neurologically intact survival in adult in‐hospital and out‐of‐hospital cardiac arrest. Squares indicate study‐specific odds ratios. Horizontal lines indicate 95% confidence intervals of the estimate. Squares to the right of the solid vertical line favor the intervention group, but this is conventionally significant (P < 0.05) only if the horizontal line does not overlap the solid line. The studies are ordered by alphabetical order within each outcome. Kim et al, ²⁰ Maekawa et al, ²¹ and Patricio et al ³⁹ reported 3 months neurologically intact survival. Sakamoto et al, ¹⁸ Schober et al, ¹⁹ and Shin et al ³² reported 6 months neurologically intact survival. Blumenstein et al, ³³ Chen et al, ³⁰ Lin et al ³¹ and Siao et al ³⁶ reported 1 year neurologically intact survival