The two new trials were conducted independently at different medical centers. Both involved infants born at less than 34 weeks of pregnancy who weighed between 500 and 1250 grams (about 1 pound to 3 pounds) at birth and who needed a ventilator to help them breathe. In one study, patients were treated with iNO within the first 48 hours of life; in the other study, treatment began between 1 week and 3 weeks of age. Combined, the studies reveal important benefits without adverse effects from iNO treatment.
"The findings from these two large, multicenter trials should help us better identify which babies might benefit from inhaled nitric oxide," noted Elizabeth G. Nabel, MD, director of NHLBI. "Successful and early treatment of breathing problems in these babies would represent a significant advance in improving the health and quality of life of a growing number of premature babies."
In the first study, nearly 800 babies were given either low-dose iNO or placebo (a harmless gas) starting within the first 48 hours of life and continuing through 21 days or until they no longer needed breathing assistance. Researchers found that the effects of iNO on survival without BPD were related to birthweight. Although treatment did not lower the overall incidence of BPD at 36 weeks, iNO appeared to cut the risk of BPD in half among the babies who weighed 1000 grams to 1250 grams (about 2.5 pounds) at birth.
In addition, significantly fewer babies treated with iNO developed brain damage, as indicated by head ultrasound. In particular, treated babies who weighed between 750 grams and 1000 grams (about 2 pounds) when they were born had half the risk of brain damage compared to babies of similar size who did not receive treatment.
"When given within the first 48 hours of life, low-dose inhaled nitric oxide reduced the risk of brain injury in very low birthweight premature newborns who required mechanical ventilation a
Contact: NHLBI Communications Office
NIH/National Heart, Lung, and Blood Institute