RESUMO
OBJECTIVE: To compare the effects of dobutamine and nitroglycerin to milrinone in young patients with severe pulmonary hypertension undergoing mitral valve replacement. DESIGN: A prospective randomized, double-blinded, controlled study. SETTING: Single university hospital. PARTICIPANTS: Forty patients had systolic pulmonary arterial pressure ≥60 mmHg and were scheduled for elective mitral valve replacement. The patients were divided randomly into 2 equal groups according to the drugs given during the study. INTERVENTIONS: The patients in group I received 5 to 20 µg/kg/min of dobutamine and 0.5 to 3 µg/kg/min of nitroglycerin, and patients in group II received a loading dose of milrinone, 50 µg/kg over 10 minutes, followed by a maintenance dose of 0.25 to 0.75 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the effects of interventional drugs on mean pulmonary artery pressure. The secondary outcomes were the effects of interventional drugs on systemic and pulmonary hemodynamic parameters measured from induction of anesthesia until the first 12 hours in the intensive care unit stay. There was a more significant decrease in mean pulmonary artery pressure, pulmonary capillary wedge pressure, and central venous pressure in group II than group I at all time points after cardiopulmonary bypass. There were more significant increases in heart rate, mean arterial pressure, cardiac output, and mixed venous oxygen tension in group I than group II, which became more obvious in time. In both groups, there was a significant decrease in systemic vascular resistance and pulmonary vascular resistance at all times. CONCLUSION: Milrinone provides adequate cardiac performance, causing a greater reduction in pulmonary artery pressure and pulmonary capillary wedge pressure.