Abstract 391: Association Between Defibrillation to Epinephrine Interval and Short-Term Outcomes in Out-of-Hospital Cardiac Arrest Patients With Shockable Rhythm

Abstract

Background: The optimal timing of epinephrine administration after defibrillation in out-of-hospital cardiac arrest (OHCA) patients with shockable rhythm is unknown. Aim: We evaluated the association between defibrillation to epinephrine interval and short-term outcomes. Methods: Between 2011 and 2020, we enrolled 1,259,960 OHCA patients from a nationwide prospective population-based registry in Japan. After applying exclusion criteria, 20,905 patients with shockable rhythm as the first documented rhythm at emergency medical services (EMS) arrival who received epinephrine after defibrillation were eligible for the study. Clinical outcomes included prehospital return of spontaneous circulation (ROSC), survival, and favorable neurological outcome at 30 days. To examine whether each variable predicted a good short-term outcome, multivariable logistic regression models were constructed using age, gender, year, district, origin of cardiac arrest, witnessed arrest, bystander-initiated cardiopulmonary resuscitation, call to EMS arrival interval, EMS arrival to defibrillation interval, and defibrillation to epinephrine interval. Results: At 30 days, 1,618 patients (8%) had a favorable neurological outcome. The defibrillation to epinephrine interval in these patients was significantly shorter than the interval in patients with an unfavorable neurological outcome [8 (5-12) vs 11 (7-16) min; P<0.001]. The proportion of patients who achieved prehospital ROSC, survived, or had a favorable neurological outcome at 30 days decreased as time to epinephrine after defibrillation increased (P<0.001 for trend). Multivariable analysis showed that shorter defibrillation to epinephrine interval independently predicted good outcomes ( Table ). Conclusion: A shorter defibrillation to epinephrine interval is significantly associated with good short-term outcomes in OHCA patients with shockable rhythm.