Prehospital Epinephrine Use and Survival among Patients with Out-of-Hospital Cardiac Arrest: Hagihara A, Hasegawa M, Abe T, Nagata T, Wakata Y, Miyazaki S. JAMA 2012; 307:1161–8.

Abstract

Epinephrine is widely used as an adjuvant to cardiopulmonary resuscitation in the setting of cardiac arrest. There is, however, little evidence to support its efficacy. Recent studies on its use have noted improved likelihood of return of spontaneous circulation (ROSC) in resuscitation, though no statistical difference in survival to hospital discharge. This Japanese study sought to determine if the use of epinephrine in the prehospital cardiac arrest setting was associated with immediate and 1-month survival. A prospective observational model was used to evaluate data on all out-of-hospital cardiac arrests (OHCA) in Japan from 2005 through 2008. There were 417,188 OHCAs meeting criteria in the time frame. Data were collected on ROSC, survival rates, and, in those who survived, neurological outcome, as measured by the Glasgow-Pittsburgh Performance Category (CPC) and the Overall Performance Category (OPC). The four primary endpoints were ROSC before hospital arrival, 1-month survival, CPC category 1 or 2, and OPC category 1 or 2 at 1-month follow-up. Epinephrine use before hospital arrival was not randomized, so a propensity score was used to control for confounding and selection bias. There were 15,030 patients matched in each group. Data were abstracted from propensity-matched patients, and multiple conditional logistic regression models were fit with endpoints as dependent variables. Crude analysis of the data revealed a positive association between prehospital epinephrine and 1-month survival (odds ratio [OR] 1.15; p < 0.001), though adjustment for propensity score and all confounding variables revealed a significant negative association (OR 0.54, p < 0.001). Epinephrine use was, however, a significant positive predictor of ROSC before hospital arrival (OR 2.51, p < 0.001). Data for CPC and OPC yielded odds ratios < 1 in all analyses for association between prehospital epinephrine use and long-term neurological outcome (OR 0.21–0.41 and 0.23–0.43 respectively, p < 0.001 for all). The authors concluded that epinephrine in the prehospital setting was strongly predictive of short-term survival, though associated with decreased 1-month survival and neurological outcome.