Vasopressin Improves Vital Organ Blood Flow During Closed-Chest Cardiopulmonary Resuscitation in Pigs

Abstract

Background This study was designed to compare the effects of epinephrine with those of vasopressin on vital organ blood flow during closed-chest cardiopulmonary resuscitation (CPR) in a pig model of ventricular fibrillation. Methods and Results Vasopressin was compared with epinephrine by randomly allocating 28 pigs to receive either 0.2 mg/kg epinephrine (n=7), 0.2 U/kg vasopressin (low dose) (n=7), 0.4 U/kg vasopressin (medium dose) (n=7), or 0.8 U/kg vasopressin (high dose) (n=7) after 4 minutes of ventricular fibrillation and 3 minutes of closed-chest CPR. Left ventricular myocardial blood flow, determined by use of radiolabeled microspheres during CPR, before and then 90 seconds and 5 minutes after drug administration was 17±2, 43±5, and 22±3 mL · min −1 · l00 g −1 (mean±SEM) in the epinephrine group; 18±2, 50±6, and 29±3 mL · min −1 · 100 g −1 in the low-dose vasopressin group; 17±3, 52±8, and 52±6 mL · min −1 · 100 g −1 in the medium-dose vasopressin group; and 18±2, 95±9, and 57±6 mL · min −1 · 100 g −1 in the high-dose vasopressin group ( P <.001 at 90 seconds and 5 minutes between epinephrine and high-dose vasopressin, and P <.01 at 5 minutes between epinephrine and medium-dose vasopressin). At the same times, calculated coronary systolic perfusion pressures were 12±2, 36±5, and 18±2 mm Hg in the epinephrine group; 10±1, 39±6, and 26±5 mm Hg in the low-dose vasopressin group; 11±2, 49±6, and 38±5 mm Hg in the medium-dose vasopressin group; and 10±2, 70±5, and 47±6 mm Hg in the high-dose vasopressin group ( P <.01 at 90 seconds and 5 minutes between epinephrine and high-dose vasopressin); and calculated coronary diastolic perfusion pressures were 15±2, 24±2, and 19±2 mm Hg in the epinephrine group; 13±1, 25±2, and 20±1 mm Hg in the low-dose vasopressin group; 13±2, 25±2, and 21±2 mm Hg in the medium-dose vasopressin group; and 13±2, 35±3, and 24±2 mm Hg in the high-dose vasopressin group ( P <.05 at 90 seconds between epinephrine and high-dose vasopressin). Total cerebral blood flow was significantly higher after high-dose vasopressin than after epinephrine ( P <.05 at 90 seconds and P <.01 at 5 minutes between groups). Five animals in the epinephrine, 5 in the low-dose vasopressin, 7 in the medium-dose vasopressin, and 6 in the high-dose vasopressin groups were successfully resuscitated and survived the 1-hour observation period. Conclusions We conclude that administration of vasopressin leads to a significantly higher coronary perfusion pressure and myocardial blood flow than epinephrine during closed-chest CPR in a pig model of ventricular fibrillation.