Early Administration of Adrenaline for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis.

Background The use of adrenaline in out-of-hospital cardiac arrest (OHCA) patients is still controversial. This study aimed to determine the effects of early pre-hospital adrenaline administration in OHCA patients. Methods and Results PubMed, EMBASE, Google Scholar, and the Cochrane Library database were searched from study inception to February 2019 to identify studies that reported OHCA patients who received adrenaline. The primary outcome was survival to discharge, and the secondary outcomes were return of spontaneous circulation, favorable neurological outcome, and survival to hospital admission. A total of 574 392 patients were included from 24 studies. The use of early pre-hospital adrenaline administration in OHCA patients was associated with a significant increase in survival to discharge (risk ratio [RR], 1.62; 95% CI, 1.45-1.83; P <0.001) and return of spontaneous circulation (RR, 1.50; 95% CI, 1.36-1.67; P <0.001), as well as a favorable neurological outcome (RR, 2.09; 95% CI, 1.73-2.52; P <0.001). Patients with shockable rhythm cardiac arrest had a significantly higher rate of survival to discharge (RR, 5.86; 95% CI, 4.25-8.07; P <0.001) and more favorable neurological outcomes (RR, 5.10; 95% CI, 2.90-8.97; P <0.001) than non-shockable rhythm cardiac arrest patients. Conclusions Early pre-hospital administration of adrenaline to OHCA patients might increase the survival to discharge, return of spontaneous circulation, and favorable neurological outcomes. Registration URL: https://www.crd.york.ac.uk/PROSPERO; Unique identifier: CRD42019130542.