INHALED NITRIC-OXIDE AS A THERAPY FOR PULMONARY-HYPERTENSION AFTER OPERATIONS FOR CONGENITAL HEART-DEFECTS

Seventeen infants were treated with inhaled nitric oxide for critical pulmonary artery hypertension after operations for congenital heart de fects. In all 17 patients conventional medical therapy consisting of h yperventilation; deep sedation/analgesia, and correction of metabolic acidosis had failed. All children were monitored with a transthoracic pulmonary artery catheter inserted at operation. Pulmonary artery hype rtension was defined as an acute rise in pulmonary pressure associated with a decrease in oxygen arterial or venous saturation. After failur e of conventional medical therapy, 20 ppm of inhaled nitric oxide was administered to the patient. In all patients the pulmonary pressures d ecreased (mean pulmonary arterial pressure decreased by -34% +/- 21%) without significant change in systemic arterial pressure, whereas the oxygen arterial saturation and oxygen venous saturation increased by 9 .7% +/- 12% and 37% +/- 28%, respectively. Fifteen children were disch arged from the intensive care unit at 10 +/- 6 days (range 3 to 26 day s) and two died. This study demonstrates that inhaled nitric oxide exe rts a selective pulmonary vasodilation without decreasing systemic art erial pressure in children with congenital heart disease. The increase d values of mixed venous oxygen saturation and urinary output suggest that this selective lowering of pulmonary vascular resistance improved the overall hemodynamics. The potential toxic effects of nitric oxide and nitrogen dioxide necessitate careful consideration of the risks a nd benefits of inhaled nitric oxide therapy.