Study shows inhaled nitric oxide reduces lung disease in premature babies

The clinical trial included 21 neonatal intensive care units throughout the US, enrolling infants with birth weights between 500g and 1,250g. Their median gestational age was 26 weeks.

All the infants were receiving oxygen through ventilators and were at high risk of developing chronic lung disease, also known as bronchopulmonary dysplasia, because their lungs were immature and underdeveloped. In this condition, scarring and inflammation in lung tissue make breathing difficult, and the infant often requires prolonged mechanical ventilation and hospitalization.

Although treatment with nitric oxide, a substance naturally produced in the body, is already known to benefit full-term infants with pulmonary hypertension, its value for preterm infants was uncertain.

The trial was randomized and double-blinded, with 294 infants receiving inhaled nitric oxide and 288 receiving a placebo. The rate of survival without chronic lung disease at 36 weeks after the mother’s last menstrual period was 43.9% in treated infants compared to 36.8% in the control group.

The effect was more pronounced for the infants entered earlier (between seven and 14 days): 49.1% in treated infants vs. 27.8% in controls. Lung disease was also less severe in treated infants at 40 and 44 weeks, with treated infants having shorter hospitalizations and less need for mechanical ventilation or oxygen therapy than the control infants.

The research team expects to provide definitive recommendations for clinical use of nitric oxide after it analyzes follow-up studies of the children’s neurodevelopmental status at two years of age. The follow-up studies are expected to be completed by the end of 2007.