Study Overview
Objective. To assess the safety and effectiveness of the use of epinephrine in out-of-hospital cardiac arrest patients.
Design. Randomized, double-blind placebo-controlled trial in the United Kingdom.
Setting and participants. Patients aged 16 years or older who had sustained an out-of-hospital cardiac arrest for which advanced life support was provided by trial-trained paramedics were eligible for inclusion. Exclusion criteria included apparent pregnancy, arrest from anaphylaxis or asthma, or the administration of epinephrine before the arrival of the trial-trained paramedic. In 1 of the 5 ambulance services, traumatic cardiac arrests were also excluded in accordance with local protocol.
Main outcome measures. The primary outcome was the rate of survival at 30 days. Secondary outcomes included rate of survival until hospital admission, length of stay in the hospital and intensive care unit (ICU), rates of survival at hospital discharge and at 3 months, and neurologic outcomes at hospital discharge and at 3 months.
Main results. Between December 2014 and October 2017, 10,623 patients were screened for eligibility in 5 National Health Service ambulance services in the United Kingdom. Of these, 8103 were eligible, and 8014 patients were assigned to either the epinephrine group (4015 patients) or the placebo group (3999 patients).
For the primary outcome, 130 patients (3.2%) in the epinephrine group were alive at 30 days in comparison to 94 patients (2.4%) in the placebo group (unadjusted odds ratio [OR] for survival, 1.39; 95% confidence interval [CI], 1.06-1.82; P = 0.02). The number needed to treat for a 30-day survival was 112 patients (95% CI, 63-500).
For the secondary outcomes, the epinephrine group had a higher survival until hospital admission: 947 patients (23.8%) as compared to 319 (8.0%) patients in the placebo group (unadjusted OR, 3.59). Otherwise, there were no difference between the 2 groups in the hospital and ICU LOS. There also was not a significant difference between the epinephrine group and the placebo group in the proportion of patients who survived until hospital discharge: 87 of 4007 patients (2.2%) in the epinephrine group and 74 of 3994 patients (1.9%) in the placebo group, with an unadjusted OR of 1.18 (95% CI, 0.85-1.61). Patients in the epinephrine group had a higher rate of severe neurologic impairment at discharge: 39 of 126 patients (31.0%) versus 16 of 90 patients (17.8%).