Epinephrine improves certain out-of-hospital cardiac arrest survival outcomes

Epinephrine, given either at standard or high dose or in combination with vasopressin during out-of-hospital cardiac arrest (OHCA) resuscitation, leads to more favourable return of spontaneous circulation (ROSC) and survival to hospital admission but not survival to discharge or functional outcome, according to a study.

Researchers conducted a systematic review and network meta-analysis of randomized controlled trials in which the effect of epinephrine use was examined during OHCA resuscitation. They searched multiple online databases and identified 18 trials for inclusion in the meta-analysis.

Frequentist random-effects network meta-analysis was used to synthesize data, and the certainty of evidence was rated using GRADE. Study outcomes were ROSC, survival to hospital admission, survival to discharge, and survival with good functional outcome.

The trials comprised a total of 21,594 people with OHCA. ROSC was more favourable after treatment with high-dose epinephrine (odds ratio [OR], 4.27, 95 percent confidence interval [CI], 3.68–4.97), standard-dose epinephrine (OR, 3.69, 95 percent CI, 3.32–4.10), and epinephrine plus vasopressin (OR, 3.54, 95 percent CI, 2.94–4.26) compared with placebo/no treatment.

Likewise, the odds of survival to hospital admission were greater with epinephrine than with placebo or no treatment (high dose: OR, 3.53, 95 percent CI, 2.97–4.20; standard dose: OR, 3.00, 95 percent CI, 2.66–3.38; epinephrine plus vasopressin: OR, 2.79, 95 percent CI, 2.27–3.44).

Meanwhile, neither survival to discharge nor survival with good functional outcome improved with epinephrine vs placebo/no treatment.

In a subgroup analysis, standard-dose epinephrine had a favourable effect on survival to discharge among patients with nonshockable rhythm (OR, 2.10, 95 percent CI, 1.21–3.63) but not among those with shockable rhythm (OR, 0.85, 95 percent CI, 0.39–1.85).