Inhaled
nitric oxide was utilized for the management of residual
pulmonary hypertension in 24 children following surgical correction of their underlying heart defects. Their ages ranged from 15 days to 14 months (median 5 months). Pulmonary artery
hypertension was diagnosed either by direct pulmonary artery pressure monitoring or by echocardiography. Inhaled
nitric oxide was used electively in 22 patients when the ratio of the mean pulmonary arterial pressure and mean systemic arterial pressure exceeded 0.5. In the remaining 2 patients,
nitric oxide was used only to manage a pulmonary
hypertensive crisis. Inhaled
nitric oxide was also used a second time in 2 patients who developed delayed pulmonary
hypertensive crisis. Twenty-two patients showed an initial response to
therapy and the pulmonary artery pressures dropped significantly. Of the patients on direct pulmonary artery pressure monitoring, a pulmonary artery to systemic artery pressure ratio below 0.3 on prolonged
therapy was associated with a survival ratio of 4/6 (including 1 neurological death and one reoperation); that between 0.3 and 0.5 with a survival ratio of 3/4. Three out of four patients with sustained echocardiographic and clinical response also survived and were discharged from the hospital. All the patients who showed a lack of response to (n=2), tolerance to (n=1), or dependence on (n=6) the use of inhaled
nitric oxide died. In addition, all 5 patients who had a pulmonary
hypertensive crisis died, 3 in spite of successful
resuscitation with
nitric oxide. Thus, excluding one neurological death and one re-operation, only 9 (41%) out of 22 patients survived.
CONCLUSIONS: