Risk of arrhythmia in post-resuscitative shock after out-of-hospital cardiac arrest with epinephrine versus norepinephrine

Objective: To determine the rates of clinically significant tachyarrhythmias and mortality in the management of post-resuscitative shock after return of spontaneous circulation (ROSC) in patients with out-of-hospital cardiac arrest (OHCA) who receive a continuous epinephrine versus norepinephrine infusion. Design: Retrospective cohort study. Setting: A large multi-site health system with hospitals across the United States. Patients: Adult patients admitted for OHCA with post-resuscitative shock managed with either epinephrine or norepinephrine infusions within 6 h of ROSC. Interventions: None. Measurements and main results: Between May 5^th, 2018, to January 31^st, 2022, there were 221 patients admitted for OHCA who received post-resuscitative epinephrine or norepinephrine infusions. There was no difference in the rate of tachyarrhythmias between epinephrine and norepinephrine infusion in univariate (47.1% vs 41.7%, OR 1.24, 95% CI 0.71–2.20) or multivariable analysis (OR 1.34, 95% CI 0.68–2.62). Patients treated with epinephrine were more likely to die during hospitalization than those treated with norepinephrine (90.0% vs 54.3%, OR 6.21, 95% CI 2.37–16.25, p < 0.001). Epinephrine treated patients were more likely to have re-arrest during hospital admission (55.7% vs 14.6%, OR 5.77, 95% CI 2.74–12.18, p < 0.001). Conclusion: There was no statistically significant difference in clinically significant cardiac tachyarrhythmias in post-OHCA patients treated with epinephrine versus norepinephrine infusions after ROSC. Re-arrest rates and in-hospital mortality were higher in patients who received epinephrine infusions in the first 6 h post-ROSC. Results of this study add to the literature suggesting norepinephrine may be the vasopressor of choice in post-OHCA patients with post-resuscitative shock after ROSC.