Comparison between prostaglandin E1 and epoprostenol (prostacyclin) in infants after heart surgery.

OBJECTIVE To study the dose response characteristics of prostaglandin E1 and epoprostenol (prostacyclin) and directly to compare their effectiveness as pulmonary vasodilators in infants with pulmonary hypertension. DESIGN A crossover design with each patient receiving both drugs in random order. SETTING Infants were studied in the intensive care unit while they were sedated, paralysed, and ventilated. PATIENTS Twenty infants who had undergone corrective cardiac surgery and who were in sinus rhythm, had stable haemodynamic function, and had a pulmonary artery catheter in place. All infants were receiving dopamine and phenoxybenzamine. INTERVENTIONS Baseline haemodynamic measurements were taken and an infusion of the first drug was started at the lowest dose: after 20 minutes the measurements were repeated and the dose increased. This protocol was repeated for all doses of both drugs: 10, 30, and 100 ng/kg/min of prostaglandin E1 and 5, 10, and 25 ng/kg/min of epoprostenol. Cardiac output was measured by the pulsed Doppler ultrasound method. MAIN OUTCOME MEASURES Pulmonary and systemic vascular resistances were calculated from the cardiac output and compared by the Wilcoxon signed ranks test. RESULTS Both prostaglandin E1 and epoprostenol were effective vasodilators: 5 ng/kg/min of epoprostenol was equivalent to 30 ng/kg/min of prostaglandin E1. CONCLUSIONS Neither drug showed pulmonary specificity.