Echocardiographic outcome of infants treated as newborns with inhaled nitric oxide for severe hypoxemic respiratory failure.

Objective: To determine the cardiovascular outcome of a group of term newborns treated with inhaled nitric oxide (iNO) for severe hypoxemic respiratory failure with associated persistent pulmonary hypertension.

Study Design: We performed echocardiographic evaluations in 40 survivors treated for severe neonatal hypoxemic respiratory failure. Each of the 40 had at least 2 follow-up echocardiograms at 3 or 6 and 24 months. These studies were compared with echocardiograms done in infants in a normal, age-matched control group.

Results: Three of 31 infants met echocardiographic criteria for pulmonary hypertension at the 3-month examination. Two of the 3 had associated structural heart disease (1 with an atrial septal defect and 1 with a ventricular septal defect). At 24 months only 1 patient had pulmonary hypertension. This infant had an atrial septal defect that was surgically closed shortly after the 24-month echocardiogram because of the pulmonary hypertension. Group comparisons of 3- and 24-month echocardiographic variables showed no differences between the study and control groups. In the 31 infants in whom serial studies were completed, expected age-related changes were demonstrated between the 3- and 24-month examinations.

Conclusions: The incidence of residual pulmonary hypertension in infants treated as newborns for severe hypoxemic respiratory failure is low. The group at highest risk is those with structural heart disease.