Nitric Oxide Helps Some Preemies, Not Others

Two studies published in the New England Journal of Medicine address the use of nitric oxide to treat premature babies, each with somewhat different results.

The results implicate that while there may be a developmental benefit to nitric oxide therapy, it may be detrimental to the earliest born preemies, especially those with serious lung conditions. Further study will be required to investigate to claims.

Researchers at the University of Chicago concluded that premature babies that had small amounts of nitric oxide added to oxygen treatment were beneficial to their underdeveloped lungs and reduced the chances delayed mental development and disability, such as cerebral palsy, two years later.

The researchers said that nearly half of premature babies developed severe disabilities such as blindness, hearing loss, and cerebral palsy. Their tests of nitric oxide, however, showed that treatment with the gas cut those developmental disabilities in half. An earlier study reported that babies were also less likely to develop chronic lung disease.
However, a separate study published in the journal delivered less hopeful results, casting doubt on the effectiveness of nitric oxide on the smallest preemies and those with more severe lung conditions. In fact, in addition to having little to no effect, nitric oxide was shown to cause brain hemorrhaging that could lead to death.

The National Institute of Child and Human Development (NICHD) studied 420 preemies with severe breathing problems and found that the use of nitric oxide therapy showed no improvement in lung development when compared to babies that had not received the treatment. About half of the infants died in both the control group and the treatment group. The smallest babies showed an increased risk of cranial bleeding and death.

On the whole, the babies in the NICHD studied smaller babies with more severe lung damage than the babies in the Chicago study.

The size of the babies and the severity of lung problems appears to be the reason for the conflicting results. The Chicago study used bigger babies with less severe lung problems and exposed them to nitric oxide for longer periods of time.

The disparity in results led the NICHD to advise that preemies weighing less than 3 pounds, 2 ounces should not be given nitric oxide therapy and that more study was required.

“At this point, nitric oxide use should be used only within clinical trials until we can determine who will benefit,” said Dr. Krisa Van Meurs, the lead investigator in the NICHD study.

Dr. Michael Schreiber, lead researcher in the U. of C. study seems to agree that more research is needed.

“Nitric oxide helps a certain group of premature babies–which exact babies it will help, we do not know yet,” Schreiber said. “It does not appear to help the really critical ones, but the babies with a moderate amount of lung disease, it does help.”