Epinephrine before defibrillation in patients with shockable in-hospital cardiac arrest: Propensity matched analysis

Objective To determine the use of epinephrine (adrenaline) before defibrillation for treatment of in-hospital cardiac arrest due to a ventricular arrhythmia and examine its association with patient survival. Design Propensity matched analysis. Setting 2000-18 data from 497 hospitals participating in the American Heart Association's Get With The Guidelines-Resuscitation registry. Participants Adults aged 18 and older with an index in-hospital cardiac arrest due to an initial shockable rhythm treated with defibrillation. Interventions Administration of epinephrine before first defibrillation. Main outcome measures Survival to discharge; favorable neurological survival, defined as survival to discharge with none, mild, or moderate neurological disability measured using cerebral performance category scores; and survival after acute resuscitation (that is, return of spontaneous circulation for >20 minutes). A time dependent, propensity matched analysis was performed to adjust for confounding due to indication and evaluate the independent association of epinephrine before defibrillation with study outcomes. Results Among 34 820 patients with an initial shockable rhythm, 9630 (27.6%) were treated with epinephrine before defibrillation, contrary to current guidelines. In comparison with participants treated with defibrillation first, participants receiving epinephrine first were less likely to have a history of myocardial infarction or heart failure, but more likely to have renal failure, sepsis, pneumonia, and receive mechanical ventilation before in-hospital cardiac arrest (P<0.0001 for all). Treatment with epinephrine before defibrillation was strongly associated with delayed defibrillation (median 3 minutes v 0 minutes). In propensity matched analysis (9011 matched pairs), epinephrine before defibrillation was associated with lower odds of survival to discharge (25.2% v 29.9%; adjusted odds ratio 0.81, 95% confidence interval 0.74 to 0.88; P<0.001), favorable neurological survival (18.6% v 21.4%; 0.85, 0.76 to 0.92; P<0.001), and survival after acute resuscitation (64.4% v 69.4%; 0.76, 0.70 to 0.83; P<0.001). The above findings were consistent in a range of sensitivity analyses, including matching according to defibrillation time. Conclusions Contrary to current guidelines that prioritize immediate defibrillation for in-hospital cardiac arrest due to a shockable rhythm, more than one in four patients are treated with epinephrine before defibrillation, which is associated with worse survival.