Best evidence in anesthetic practice. Treatment: vasopressin neither improves nor worsens survival from cardiac arrest.

Abstract

Does vasopressin, as the initial vasopressor, improve one-hour survival compared to epinephrine in inpatients with cardiac arrest? Multicentre, randomized controlled trial. Patients, caregivers, study investigators, and adjudication committee were blinded. Emergency rooms, critical care units, and wards of three teaching hospitals in Canada from July 1997 to November 1998. Two hundred inpatients with cardiac arrest from asystole, pulseless electrical activity, or refractory ventricular fibrillation. Exclusion criteria were age < 16 yr; documented terminal illness; do-not-resuscitate status; hospital admission < 24 hr after trauma; cardiac arrest before arrival to hospital, or in the operating, recovery, or delivery rooms, or from obvious exsanguination; or previous enrollment in the study. Study was approved by the research ethics committees; informed consent was not obtained. All patients were treated according to the American Heart Association Advanced Cardiac Life Support (ACLS) protocols. The intervention was applied whenever the ACLS protocol indicated epinephrine. One hundred and four patients were allocated to vasopressin 40 Uiv; 96 patients were allocated to epinephrine 1 mgiv. Both groups received epinephrine 1 mgiv every three to five minutes if there was no return of pulse. One-hour survival was the primary outcome. Survival to 24 hr, 30 days, and hospital discharge; cognitive function (mini-mental state examination and five-point cerebral performance score); return of pulse; and adverse events were secondary outcomes. Analysis was per protocol. There were no differences in survival to one hour, 24 hr, 30 days, or hospital discharge, or in cognitive function, return of pulse, and adverse events between the two groups. The sample size was powered to detect a 20% absolute difference in one-hour survival. Vasopressin neither improved nor worsened survival in cardiac arrest from asystole, pulseless electrical activity, or refractory ventricular fibrillation when compared with epinephrine. Heart and Stroke Foundation of Canada.