Outcomes associated with amiodarone and lidocaine for the treatment of adult in-hospital cardiac arrest with shock-refractory pulseless ventricular tachyarrhythmia

Abstract

Background: To determine the association between amiodarone or lidocaine and outcomes in adult in-hospital cardiac arrest (IHCA) with shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT).

Methods: A retrospective study in a single medical centre was conducted. Patients experiencing an IHCA between 2006 and 2015 were screened. Shock-refractory ventricular tachyarrhythmias were defined as VF/pVT requiring more than one defibrillation attempt. A multivariate logistic regression analysis was used to study the associations between the independent variables and outcomes.

Results: A total of 130 patients were included. Among these, 113 patients (86.9%) were administered amiodarone as the first antiarrhythmic agent (amiodarone first) following VF/pVT, and the other patients were administered lidocaine (lidocaine first). The median time to the first defibrillation and first antiarrhythmic drug administration were 2 and 9 min, respectively. The analysis demonstrated that the amiodarone-first group experienced a higher likelihood of terminating the VF/pVT within three shocks (odds ratio: 11.61, 95% confidence interval: 1.34-100.84; p-value = 0.03), as compared with the lidocaine-first group. However, there were no significant differences between the amiodarone- and lidocaine-first groups in sustained return of spontaneous circulation, survival for 24 h, survival, or favourable neurological outcomes at hospital discharge.

Conclusion: For patients with IHCA and shock-refractory VF/pVT, the adoption of an amiodarone-first strategy seemed to be associated with the termination of VF/pVT using fewer shocks. Nonetheless, because of the small sample size, additional large-scale studies should be conducted to investigate whether this advantage could be translated into a long-term benefit in survival or neurological outcomes.

Keywords: Amiodarone; Arrhythmia; Cardiopulmonary resuscitation; In-hospital cardiac arrest; Lidocaine.