The effect of inhaled nitric oxide on pulmonary function in preterm infants

Objective: Bronchopulmonary dysplasia ( BPD) in preterm infants is associated with impaired alveolar growth, inflammation and airway hyperreactivity. In animal models of BPD, inhaled nitric oxide ( NO) improves alveolar growth and inhibits airway smooth muscle proliferation. This study was designed to assess the effect of inhaled NO on resistance and compliance in ventilated preterm infants with evolving BPD. Study Design: Expiratory resistance and compliance of the respiratory system were measured in 71 ventilated preterm infants, <= 32 weeks gestation, randomized to NO ( n=34) versus placebo ( n=37) for >= 24 days at 7 to 21 days of life. Result: At baseline expiratory resistance ( 231 +/- 71 versus 215 +/- 76 cm H2O l(-1)s(-1)) and compliance ( 0.49 +/- 0.14 versus 0.53 +/- 0.13 ml cm H2O-1 kg(-1)) were comparable between placebo and NO groups, respectively. There was no effect of NO on expiratory resistance or compliance at 1 h, 1 week or 2 weeks of study gas administration. Conclusion: NO had no short-or medium-term effect on expiratory resistance or compliance in ventilated preterm infants.