Esmolol, vector change, and dose-capped epinephrine for prehospital ventricular fibrillation or pulseless ventricular tachycardia

Background: Refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest de-scribes a subset of patients who do not respond to standard Advanced Cardiac Life Support (ACLS) interventions and are associated with poor outcomes. Esmolol administration and vector change defibrillation have shown promise in improving outcomes in these patients, however evidence is limited.Objectives: This study compares clinical outcomes between patients with prehospital refractory VF/pVT who re-ceived an Emergency Medical Service (EMS) bundle, comprised of esmolol administration, vector change defi-brillation, and dose-capped epinephrine at 3 mg, to patients who received standard ACLS interventions.Methods: This multicenter, retrospective, cohort study evaluated medical records between October 18, 2017 and March 15, 2022. Patients were enrolled if they experienced a prehospital cardiac arrest with the rhythm VF or pVT, had received at least three standard defibrillations, at least 3 mg of epinephrine, and 300 mg of amiodarone. Patients who received the EMS bundle after its implementation were compared to patients who received stan-dard ACLS interventions prior to its implementation. The primary outcome was sustained return of spontaneous circulation (ROSC), defined as ROSC lasting 20 min without recurrence of cardiac arrest. Secondary outcomes in-cluded the incidence of any ROSC, survival to hospital arrival, survival at hospital discharge, and neurologically intact survival at hospital discharge.Results: Eighty-three patients were included in the study. Thirty-six were included in the pre-EMS bundle group and 47 patients were included in the post-EMS bundle group. Patients in the pre-EMS bundle group achieved sig-nificantly higher rates of sustained ROSC (58.3% vs 17%, p < 0.001), any ROSC (66.7% vs 19.1%, p < 0.001), and survival to hospital arrival (55.6% vs 17%, p < 0.001). The rates of survival to hospital discharge (16.7% vs 6.4%, p = 0.17) and neurologically intact survival at hospital discharge (5.9% vs 4.3%, p = 1.00) were not significantly different between groups.Conclusions: Patients who received the EMS bundle achieved sustained ROSC significantly less often and were less likely to have pulses at hospital arrival. The incidence of neurologically intact survival was low and similar be-tween groups.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study compares clinical outcomes between patients with refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest who received an Emergency Medical Service (EMS) bundle, and patients who received standard Advanced Cardiac Life Support (ACLS) interventions. The results showed that patients who received the EMS bundle had lower rates of successful resuscitation, fewer pulses on arrival at the hospital, and similar rates of neurologically intact survival compared to those who received standard ACLS interventions.