Amrinone versus dopamine-nitroglycerin after reconstructive surgery for complete atrioventricular septal defect

Abstract

Objectives: To compare the effectiveness and safety of amrinone and a combination of dopamine and nitroglycerin in infants after reconstructive surgery for congenital heart disease. Design: A prospective, randomized, double-blind study. Setting: Pediatric intensive care unit in a university hospital. Participants: Thirty-two infants with complete atrioventricular septal defect. Interventions: Amrinone loading dose, 2 mg/kg, followed by a maintenance infusion, 7.5 μg/kg/min, was given to 17 infants before separation from cardiopulmonary bypass. The remaining 15 patients received a combination of dopamine, 5 μg/kg/min, and nitroglycerin, 1 μg/kg/min. Measurements and Main Results: The circulatory state of the patients was evaluated from 4 to 18 hours after cardiopulmonary bypass. The systemic blood flow index, calculated using the Fick principle, was higher in the amrinone group (2.5 ± 0.7 L/min/m 2) compared with the dopamine-nitroglycerin group (2.0 ± 0.6 L/min/m 2, mean ± SD). The pulmonary blood flow index in the amrinone group was higher (2.9 ± 0.6 L/min/m 2) than in the dopaminenitroglycerin group (2.2 ± 0.6 L/min/m 2); no significant difference was noted in the mean pulmonary artery pressure. The oxygen extraction ratio was higher in the dopamine-nitroglycerin group (0.41 ± 0.07) compared with the amrinone group (0.34 ± 0.08). Despite lower platelet counts in the amrinone group, no hemorrhagic complications were seen in any patient. Conclusions: With this dosage regimen, amrinone provides a higher cardiac output, more favorable oxygen dynamics, and lower pulmonary vascular resistance than dopamine and nitroglycerin.