Mechanical versus manual chest compressions for out-of-hospital cardiac arrest: a meta-analysis of randomized controlled trials

Recent evidence regarding mechanical chest compressions in out-of-hospital cardiac arrest (OHCA) is conflicting. The objective of this study was to perform a meta-analysis of randomized controlled trials (RCTs) to compare the effect of mechanical versus manual chest compressions on resuscitation outcomes in OHCA. PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry were searched. In total, five RCTs with 12,510 participants were included. Compared with manual chest compressions, mechanical chest compressions did not significantly improve survival with good neurological outcome to hospital discharge (relative risks (RR) 0.80, 95% CI 0.61–1.04, P = 0.10; I(2) = 65%), return of spontaneous circulation (RR 1.02, 95% CI 0.95–1.09, P = 0.59; I(2) = 0%), or long-term (≥6 months) survival (RR 0.96, 95% CI 0.79–1.16, P = 0.65; I(2) = 16%). In addition, mechanical chest compressions were associated with worse survival to hospital admission (RR 0.94, 95% CI 0.89–1.00, P = 0.04; I(2) = 0%) and to hospital discharge (RR 0.88, 95% CI 0.78–0.99, P = 0.03; I(2) = 0%). Based on the current evidence, widespread use of mechanical devices for chest compressions in OHCA cannot be recommended.