Effects of inhaled nitric oxide on postoperative pulmonary circulation in patients with congenital heart disease.

We studied 22 patients with residual pulmonary hypertension or symptoms of postoperative pulmonary hypertensive crisis. They received low-dose inhalation (10 ppm) of nitric oxide (NO), a selective pulmonary vasodilator, after total correction for congenital heart anomalies. Fifteen minutes of NO inhalation improved the pulmonary circulation and lessened the imbalance in the ventilation-perfusion ratio in both groups. Thus, NO inhalation is effective in the treatment of pulmonary hypertension and in the prevention of pulmonary hypertensive crises after total correction for congenital heart anomalies. All patients continued to receive NO therapeutically. The duration of such therapeutic NO inhalation was well correlated with postoperative Qp/Qs (p = 0.014) and Rp/Rs (p = 0.029).