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 newbo rns treated with inhaled nitric oxide (iNO) for severe hypoxemic respirator y failure with associated persistent pulmonary hypertension. Study design: We performed echocardiographic evaluations in 40 survivors tr eated 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 studie s were compared with echocardiograms done in infants in a normal, age-match ed control group. Results: Three of 31 infants met echocardiographic criteria for pulmonary h ypertension at the 3-month examination. Two of the 3 had associated structu ral heart disease (1 with an atrial septal defect and 1 with a ventricular septal defect). At 24 months only 1 patient had pulmonary hypertension. Thi s infant had an atrial septal defect that was surgically closed shortly aft er the 24-month echocardiogram because of the pulmonary hypertension. Group comparisons of 3- and 24-month echocardiographic variables showed no diffe rences between the study and control groups. In the 31 infants in whom seri al studies were completed, expected age-related changes were demonstrated b etween the 3- and 2 l-month examinations. Conclusions: The incidence of residual pulmonary hypertension in infants tr eated as newborns for severe hypoxemic respiratory failure is low. The grou p at highest risk is those with structural heart disease.