Vasopressin improves vital organ blood flow after prolonged cardiac arrestwith postcountershock pulseless electrical activity in pigs

Objective: Although a benefit of vasopressin when compared with epinephrine was shown during cardiopulmonary resuscitation (CPR) after a short duratio n of ventricular fibrillation cardiac arrest, the effect of vasopressin dur ing prolonged cardiac arrest with pulseless electrical activity is currentl y unknown, Design: Prospective, randomized laboratory investigation using an establish ed porcine model with instrumentation for measurement of hemodynamic variab les, vital organ blood flow, blood gases, and return of spontaneous circula tion, Setting: University hospital laboratory, Subjects: Eighteen domestic pigs, Interventions: After 15 mins of cardiac arrest and 3 mins of chest compress ions, 18 animals were randomly treated with either 0.8 units/kg vasopressin (n = 9) or 200 mu g/kg epinephrine (n = 9), Measurements and Main Results: Compared with epinephrine, vasopressin resul ted, at both 90 sees and 5 mins after drug administration, in significantly higher (p < .05) median (25th-75th percentiles) left ventricular myocardia l blood flow (120 [range, 96-193] vs, 54 [range, 11-92] and 56 [range, 41-8 0] vs, 21 [range, 11-40] mL/min/100 g, respectively) and total cerebral blo od flow (85 [78-102] vs, 24 [18-41] and 50 [44-52] vs. 8 [5-23] mL/min/100 g, respectively). Spontaneous circulation was restored In eight of nine ani mals in the vasopressin group and in one of nine animals in the epinephrine group (p = .003), Conclusions: Compared with a maximum dose of epinephrine, vasopressin signi ficantly increased left ventricular myocardial and total cerebral blood flo w during CPR and return of spontaneous circulation in a porcine model of pr olonged cardiac arrest;with postcountershock pulseless electrical activity.