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

Abstract

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, 7054 (20.3%) 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, respiratory insufficiency, and receive mechanical ventilation before in-hospital cardiac arrest (standardized differences >10% for all). Treatment with epinephrine before defibrillation was strongly associated with delayed defibrillation (median 4 minutes v 0 minutes). In propensity matched analysis (6569 matched pairs), epinephrine before defibrillation was associated with lower odds of survival to discharge (22.4% v 29.7%; adjusted odds ratio 0.69; 95% confidence interval 0.64 to 0.74; P<0.001), favorable neurological survival (15.8% v 21.6%; 0.68; 0.61 to 0.76; P<0.001) and survival after acute resuscitation (61.7% v 69.5%; 0.73; 0.67 to 0.79; 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, one in five patients are treated with epinephrine before defibrillation. Use of epinephrine before defibrillation was associated with worse survival outcomes.

Fig 1

Study cohort. The flow chart shows the derivation of the study cohort after applying the study’s inclusion and exclusion criteria, and the number of participants excluded at each step

Fig 2

Proportion of participants receiving epinephrine (adrenaline) first or defibrillation first by time to defibrillation. The yellow bars represent the proportion of participants receiving epinephrine first and the purple bars represent the proportion of participants receiving defibrillation first (that is, without prior epinephrine). The figure shows that the proportion of patients receiving epinephrine first was associated with increasing delay in time to defibrillation

Fig 3

Rates of survival in patients receiving epinephrine (adrenaline) first versus defibrillation first stratified according to the time to defibrillation. The yellow circles represent survival in participants receiving epinephrine first and the purple squares represent survival in participants who received defibrillation first. The pink dashed line represents the overall survival rate in the entire cohort. The figure shows that in comparison with survival in participants receiving defibrillation first, survival in patients receiving epinephrine first was lower regardless of time to defibrillation