WEDNESDAY, Nov. 26, 2003 (HealthDayNews) -- Premature babies are less likely to develop chronic lung problems if they are given inhaled nitric oxide in the first week of life, a new study says.
Preemies are subject to many life-threatening problems, with nearly one-fourth developing respiratory distress syndrome.
About 60,000 children in the United States are born each year weighing less than three pounds. Of those who survive, many suffer permanent lung damage, which can slow growth, increase the possibility of infection, and result in abnormal brain development.
The infants with respiratory distress syndrome are at a very high risk of dying despite aggressive treatment, which can include a mechanical respirator.
"We gave inhaled nitric oxide to premature infants who were at risk for developing chronic lung disease or dying," says Dr. Michael Schreiber, an associate professor of pediatrics at the University of Chicago Hospitals. "By giving them the drug early in the course of treatment, we could decrease the chances of them developing chronic lung disease or dying," he adds.
Schreiber and his colleagues randomly assigned 207 premature infants who were receiving mechanical ventilation to standard care plus nitric oxide or standard care and a placebo, according to a report in the Nov. 27 issue of the New England Journal of Medicine. The babies were born at or before 34 weeks of gestation.
The researchers found that 64 percent of the babies who received standard therapy died or developed chronic lung disease, compared with only 49 percent of those who received standard therapy plus inhaled nitric oxide.
Nitric oxide causes the blood vessels in the lungs to relax, allowing more blood to get into the lung and thus allowing more oxygen to get into the infants' circulating blood. It also acts as an anti-inflammatory that works to prevent chronic lung disease, Schreiber says.
However, nitric oxide can increase the chance of bleeding in the brain. But in this study, the researchers found that not only did nitric oxide not increase bleeding, but also it actually decreased bleeding.
"We reasoned that babies with the sickest lungs are the ones most likely to have bleeding in the brain," Schreiber says. "If we could make their lungs better, then we hoped the overall condition of the baby would improve. In fact, that's what we found."
This is the first time nitric oxide therapy has been used in premature infants with mild-to-moderate disease, but severe enough to require mechanical ventilation. It has been used successfully before in full-term and near-term babies with respiratory problems, according to Schreiber.
There are three trials under way, Schreiber notes. "If those trials confirm our results, then nitric oxide could be used in virtually all premature infants sick enough to require mechanical ventilation, greatly reducing the incidence of chronic lung disease," he says.
"Someday this will be another tool that we can use to help these extremely small and fragile babies," Schreiber adds.
"This an intriguing and potentially exciting new therapy to try and prevent lung injury in premature babies," says Dr. Richard J. Martin, author of an accompanying editorial in the journal and a professor of pediatrics at Case Western Reserve University in Cleveland.
But it is a relatively small study, he adds, and experts need to see the results from other large, ongoing studies before making this treatment a standard part of clinical care.
"This is the first study which has shown the benefit of nitric oxide therapy in premature babies, and we need to worry about the safety of any new therapy in a premature infant," he cautions.
More information
To learn more about premature infants, visit Neonatology on the Web or the Nemours Foundation.
