How Epinephrine Administration Interval Impacts the Outcomes of Resuscitation during Adult Cardiac Arrest: A Systematic Review and Meta-Analysis.

Current guidelines for treating cardiac arrest recommend administering 1 mg of epinephrine every 3-5 min. However, this interval is based solely on expert opinion. We aimed to investigate the impact of the epinephrine administration interval (EAI) on resuscitation outcomes in adults with cardiac arrest. We systematically reviewed the PubMed, EMBASE, and Scopus databases. We included studies comparing different EAIs in adult cardiac arrest patients with reported neurological outcomes. Pooled estimates were calculated using the IVhet meta-analysis, and the heterogeneities were assessed using Q and I 2 statistics. We evaluated the study risk of bias and overall quality using validated bias assessment tools. Three studies were included. All were classified as "good quality" studies. Only two reported the primary outcome. Compared with a recommended EAI of 3-5 min, a favorable neurological outcome was not significantly different in patients with the other frequencies: for <3 min, odds ratio (OR) 1.93 (95% CI: 0.82-4.54); for >5 min, OR 1.01 (95% CI: 0.55-1.87). For survival to hospital discharge, administering epinephrine for less than 3 min was not associated with a good outcome (OR 1.66, 95% CI: 0.89-3.10). Moreover, EAI of >5 min did not pose a benefit (OR 0.87, 95% CI: 0.68-1.11). Our review showed that EAI during CPR was not associated with better hospital outcomes. Further clinical trials are necessary to determine the optimal dosing interval for epinephrine in adults with cardiac arrest.