ObjectiveThe administration of vasopressin during cardiopulmonary resuscitation (CPR) provides significantly more vital organ blood flow when compared with epinephrine during cardiac arrest in pigs. The effects of this potent vasoconstrictor on postresuscitation cardiovascular function remain unknown. The purpose of this study was to compare the effects of vasopressin and epinephrine on cardiovascular function in the postresuscitation phase after CPR.DesignProspective, randomized, experimental study.SettingUniversity research laboratory.SubjectsDomestic pigs, 12 to 14 wks of age.InterventionsSixteen pigs were randomly allocated to receive either 0.045 mg/kg of epinephrine or 0.4 U/kg of vasopressin after 4 mins of cardiac arrest.Measurements and Main ResultsHemodynamics, left ventricular contractility, and myocardial blood flow were measured for an interval of 240 mins after successful CPR. Differences between animals treated with epinephrine vs. vasopressin were most pronounced 15 mins after restoration of spontaneous circulation. At this time, mean aortic pressure was 64 +/- 6 (SEM) mm Hg in the epinephrine group and 84 +/- 6 mm Hg (p < .05) in the vasopressin group. Systemic vascular resistance was 1285 +/- 72 dyne [centered dot] sec/cm5in the epinephrine group and 2314 +/- 130 dyne [centered dot] sec/cm5(p < .001) in the vasopressin group. Cardiac index was 140 +/- 9 mL/min/kg in animals treated with epinephrine and 99 +/- 9 mL/min/kg (p < .01) in animals treated with vasopressin. Myocardial contractility (dp/dtmax/P) was 52.8 +/- 3.4/sec with epinephrine as compared with 36.3 +/- 2.9 sec sup -1 (p < .01) with vasopressin. Left ventricular epicardial blood flow was 241 +/- 35 mL/min/100 g with epinephrine and 142 +/- 22 mL/min/100 g (p < .05) with vasopressin. Four hours after CPR, no significant differences were observed between groups.ConclusionsIn the early postresuscitation phase, vasopressin provided higher systemic blood pressures and there was a reversible depressant effect on myocardial function when compared with epinephrine. Overall cardiovascular function was not irreversibly or critically impaired after the administration of vasopressin in this pig model of cardiac arrest. (Crit Care Med 1996; 24:2014-2019)