Effect of nitric oxide on oxygenation and hemodynamics in infants after cardiac surgery.

Abstract

We evaluated the effect of nitric oxide (NO) on infants after congenital cardiac surgery. Inhaled NO was administered to 7 infants after congenital cardiac surgery. Inhaled NO concentration ranged from 2.5 to 10 parts per million (ppm). The respiratory index (RI = A-aDO2/PaO2) decreased from 7.4 +/- 2.5 to 4.7 +/- 3.1 in the right RI group (RI > or = 3, n = 4) 30 min after NO inhalation. After discontinuation of NO inhalation, RI increased to the preinhalation level. NO inhalation was restarted in 2 patients in the high RI group because of severe worsening of oxygenation. RI was not affected by starting or discontinuing of NO in the low RI group (RI < 3, n = 3). Systemic blood pressure did not significantly change in the 2 groups. Pulmonary arterial pressure (PAP) was measured in 4 patients, and it decreased by 21, 10, and 10%, respectively, 30 min after NO inhalation in 3 patients, but did not change in the remaining patient. After discontinuation of NO inhalation, PAP increased in all patients, and in 2 cases, PAP was higher than baseline value. NO inhalation is effective in improving oxygenation in infants with a high RI after cardiac surgery. However, careful monitoring of the respiratory and hemodynamic states is required after discontinuing NO inhalation.