RESUMEN
OBJECTIVE: To evaluate the time-independent effect of the early administration of epinephrine (EPI) on favorable neurological outcome (as CPC [cerebral performance category] 1-2) at 1 month in patients with out-of-hospital cardiac arrest. MATERIALS AND METHODS: A total of 119 639 witnessed cardiac arrest patients from 2008 to 2012 were eligible for this nationwide, prospective, population-based observational study. Patients were divided into EPI group (n = 20 420) and non-EPI group (n = 99 219). To determine the time-dependent effects of EPI, EPI-administered patients were divided into 4 groups as follows: early EPI (5-18 min), intermediate EPI (19-23 min), late EPI (24-29 min), and very late EPI (30-62 min), respectively. Multiple logistic regression analyses and adjusted odds ratios (AORs) were determined for CPC 1-2 at 1 month (primary outcome) and field return of spontaneous circulation (as secondary outcome) among the groups. RESULTS: The EPI and non-EPI group had identical background, but EPI group shows higher incidence public access defibrillation and emergency medical technician defibrillation delivered than the non-EPI group. The differences were clinically negligible. Higher return of spontaneous circulation rate (18.0%) and lower CPC 1-2 (2.9%) shown in the EPI group than in the non-EPI group (9.4% and 5.2%). In the time dependent analysis, CPC 1 to 2 was greatest in the early EPI group (AOR, 2.49; 95% confidence interval [CI], 1.90-3.27), followed by the intermediate EPI group (AOR, 1.53; 95% CI, 1.14-2.05) then the late EPI group (AOR, 0.71; 95% CI, 0.47-1.08) as reference. CONCLUSION: Early EPI administration within 19 minutes after emergency medical service call independently improved the neurological outcome compared with late EPI (24-29 minutes) administration in patients with out-of-hospital cardiac arrest.