Inhaled nitric oxide can benefit some preemies

NEW YORK (Reuters Health) - Infants born prematurely are at increased risk for a chronic lung disease, called bronchopulmonary dysplasia, associated with prolonged use of oxygen therapy or a respirator.

Now, new research suggests that adding nitric oxide (NO) to the air they breathe can reduce that risk in some infants, and may also improve other outcomes, according to two papers in The New England Journal of Medicine.

Although NO is effective in treating lung disease in full-term infants, recent studies of premature infants have produced divergent results, Dr. Roberta A. Ballard, from Children's Hospital in Philadelphia, and her associates point out in the first study.

To further assess this treatment, Ballard's group included in their multicenter study nearly 600 preterm infants who required a respirator between 7 and 21 days of age. The patients were treated at one of 21 infant intensive care units in the US.

The patients were randomly selected to receive NO beginning on day 7 and continued for at least 24 days, or inactive "placebo" treatment.

Compared with infants given placebo, those treated with NO were less likely to develop bronchopulmonary dysplasia and were discharged earlier and required supplemental oxygen therapy for a shorter period.

No side effects from inhaled NO were seen.

The second study, led by Dr. John P. Kinsella at Children's Hospital in Denver, was similar to that by Ballard's group. The subjects included 793 preemies who required a respirator.

The infants were randomly assigned to placebo or inhaled NO for 21 days or until they were successful weaned off of the respirator. Treatment was begun within 48 hours of birth and lasted for around 14 days.

Overall, there was no significant difference between groups in survival or the development of bronchopulmonary dysplasia. However, inhaled NO did seem to reduce the occurrence of bronchopulmonary dysplasia among infants weighing between 1000 and 1250 grams.

NO therapy also seemed to protect against a number of potentially serious neurologic conditions, such as bleeding within the brain.

Ballard's team compared the two studies to determine factors that could account for their different outcomes. They found that in their study, NO therapy was started no sooner than 7 days after birth, versus starting on day 1 or 2 in the group led by Kinsella. The duration as well as the peak and total dose of NO were also higher.

SOURCE: The New England Journal of Medicine, July 27, 2006.