Nitric oxide is superior to prostacyclin for pulmonary hypertension after cardiac operations

Background. Severe pulmonary hypertension is still a cause of morbidity and mortality in children after cardiac operations. The objective of this study was to compare the vasodilator properties of inhaled nitric oxide, a novel pulmonary vasodilator, and intravenous prostacyclin in the treatment of severe postoperative pulmonary hypertension. Methods. Thirteen children (aged 3 days to 12 months) with severe pulmonary hypertension after cardiac operations were given inhaled nitric oxide (20 ppm × 10 minutes) and intravenous prostacyclin (20 ng · kg−1 · min−1 × 10 minutes) in a prospective, randomized cross-over study. Results. Both nitric oxide and prostacyclin resulted in a reduction in pulmonary arterial pressure, although the mean pulmonary arterial pressure was significantly lower during nitric oxide therapy (28.5 ± 2.9 mm Hg) than during prostacyclin therapy (35.4 ± 2.1 mm Hg; p < 0.05). The mean pulmonary to systemic arterial pressure ratio was also significantly lower during nitric oxide than prostacylin administration (0.46 ± 0.04 versus 0.68 ± 0.05; p < 0.01), due mainly to only prostacyclin lowering systemic blood pressure. Conclusions. Inhaled nitric oxide was a more effective and selective pulmonary vasodilator than prostacyclin and should be considered as the preferred treatment for severe postoperative pulmonary hypertension.