Letting some premature babies inhale small amounts of nitric oxide may prevent a potentially fatal lung disease known as bronchopulmonary dysplasia, two studies showed Wednesday.
Thousands of babies are born each year in the United States with lungs too immature to properly mix inhaled air with blood so that the oxygen can be pumped to the cells of the body. Progress in fighting the problem, which can cause brain damage, has been limited.
The studies published in this week’s New England Journal of Medicine said their findings were not conclusive enough to recommend routine treatment and that further tests were needed to ensure a child’s development was not harmed.
They also used different strategies to deliver nitric oxide, a compound that plays a key role in the heart and circulatory system, to their tiny patients.
One study led by John Kinsella of the University of Colorado School of Medicine involved giving the gas soon after birth and found that the treatment only seemed to help babies weighing at least 2.2 pounds.
But it cut their risk of lung problems in half. It didn’t show a breathing benefit for smaller babies who were on ventilators and received the gas. But for all babies who took part in the test it halved the risk of brain damage.
“We are optimistic that this therapy could prevent long-term developmental and neurological problems in many of these children,” Kinsella said.
The 793 babies in 16 centers started receiving the gas or a placebo when they were less than 48 hours old.
Cost of treatment cited
The other study led by Roberta Ballard of Children’s Hospital of Philadelphia gave 582 babies nitric oxide or a placebo only after they were at least seven days old.
Those researchers found that, after 36 weeks, 44 percent of the nitric oxide recipients were free of bronchopulmonary dysplasia versus 37 percent who got a placebo gas.
“As compared with infants who received placebo gas, infants who were treated with inhaled nitric oxide were hospitalized for fewer days, needed supplemental oxygen for a shorter period, and had less severe disease,” the Ballard team said.
Ballard told Reuters that the Kinsella team may not have seen significant improvement in some babies because they may have halted the treatment too soon.
At a cost of about $3,000 per day, or as much as $12,000 for a month of therapy, nitric oxide for premature newborns “is difficult to justify until benefit is proven,” said Ann Stark of Texas Children’s Hospital in Houston, whose editorial in the Journal recommends that “the use of inhaled nitric oxide in this setting should be limited to clinical trials.”
About 10,000 newborns develop bronchopulmonary dysplasia in the United States each year.
The U.S. Food and Drug Administration has approved the gas for full-term babies with breathing problems.
Its use in smaller infants is of intense interest for doctors because about one in three babies who weigh less than 2.75 pounds at birth have the disease and need supplemental oxygen.
Of those, at least 10 percent have evidence of brain injury.