Although inhaled nitric oxide (iNO) is used in the treatment of persistent pulmonary hypertension of the newborn (PPHN), little is known of its potential long term toxic effects. By decreasing intrapulmonary and extrapulmonary shunt iNO may decrease lung injury due to barotrauma and oxygen toxicity. Despite these benefits, there may be a potential risk of additional lung injury with NO therapy secondary to NO and the formation of NO related by-products(NO2, ONOO-). In this study we sought to determine if there were any differences in lung function of infants with PPHN treated with iNO compared to healthy control infants. Five infants (ages 6 to 9 mos) with a history of PPHN treated with iNO were compared with five normal control infants (5.5 to 6 mos of age). None of the infants were on home oxygen. Pulmonary function tests were performed using the Sensormedics 2600 Infant PFT system. Oxygen saturations were not different between study groups. Thus, NO treated infants at follow-up have normal lung mechanics, but mild elevation of FRC in comparison with normal controls. We conclude that these infants have normal lung mechanics but may have a tendency for gas trapping.Table

Table 1
Full size table