The hemodynamic effects of dopamine in infants after corrective cardiac surgery.

The hemodynamic effects of dopamine were measured during the immediate postoperative period in five infants with low cardiac output following repair of congenital cardiac defects. Dopamine was administered at doses of 5, 10, 15, 20 and 25 micrograms/kg/minute. Heart rate, systemic arterial pressure, and cardiac index increased significantly at a dose of 15 micrograms/kg/minute or greater. There were no significant changes in right atrial pressure, left atrial pressure, pulmonary artery pressure, pulmonary vascular resistance, systemic vascular resistance, or stroke volume. These data support the hypothesis that inants respond to dopamine in a fashion qualitatively and quantitatively different from that in adults.