Comparing intravenous amiodarone or lidocaine, or both, outcomes for inpatients with pulseless ventricular arrhythmias

Objective: To compare survival rates of patients with in-hospital cardiac arrest due to pulseless ventricular tachycardia/ ventricular fibrillation treated with lidocaine, amiodarone, or amiodarone plus lidocaine. Design: Multicenter retrospective medical record review. Setting: Three academic medical centers in the United States. Patients: Hospitalized adult patients who received amiodarone, lidocaine, or a combination for pulseless ventricular tachycardia/ ventricular fibrillation between August 1, 2000, and July 31, 2002. Measurements and Main Results: Data were collected according to the Utstein style. In-hospital proportion of patients living at 24 hrs and discharge were analyzed using chi-square analysis. Of the 605 patient medical records reviewed, 194 met criteria for inclusion (n = 79 for lidocaine, n = 74 for amiodarone, n = 41 for combination). Available data showed no difference in proportion of patients alive 24 hrs post-cardiac arrest (p =.39). Cox regression analysis indicated a decreased likelihood of survival in patients with pulseless ventricular tachycardia/ventricular fibrillation as an initial rhythm as compared with those who presented with bradycardia followed by pulseless ventricular tachycardia/ventricular fibrillation and in those patients who received amiodarone as compared with lidocaine. However, only 14 patients (25%) in the amiodarone group received the recommended initial 300-mg intravenous bolus, and amiodarone was administered an average of 8 mins later in the code compared with lidocaine (p <.001). Conclusions. These results generate the hypothesis that inpatients with cardiac arrest may have different benefits from lidocaine and amiodarone than previously demonstrated. Inadequate dosing and later administration of amiodarone in the code were two confounding factors in this study. Prospective studies evaluating these agents are warranted.