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

Abstract

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. 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. 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. 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.