Preterm Babies Get a Double Breath of Life

by Food and Drug Administration (FDA)

When Benjamin McClatchey was born almost three months premature on July 27, 1990, he weighed only 2 pounds, 13 ounces, and his underdeveloped lungs struggled for every breath.

Benjamin's parents, Steve and Trillis McClatchey of Lafayette, Ind., got only a glimpse of their son before doctors whisked him off to another hospital an hour away. They called Trillis McClatchey at 5 o'clock the next morning for her permission to give Benjamin a pulmonary surfactant, a new lifesaving drug, to help him breathe.

"[They] told us it worked best if given in the first six hours of life," McClatchey remembers. "I said, 'He was born at 11:10 last night — you have 10 minutes!'

"The doctor laughed. He said, 'Everything's going to be fine.'"

Benjamin received the drug and is indeed fine today. But at birth he developed respiratory distress syndrome, or RDS, a life-threatening lung condition that strikes about 65,000 infants each year. RDS has become more treatable in recent years because of surfactant and new ventilators recently approved by FDA.

RDS is common among the approximately 380,000 premature infants born in the United States each year. About 3,000 infants died of RDS in 1988, making it the fourth most common cause of all infant deaths.

RDS is also called hyaline membrane disease. In 1963, a baby boy born to then-President and Mrs. John F. Kennedy died of the condition.

But neonatal medicine has improved since then, reducing deaths from RDS steadily over the last 15 years. Preliminary statistics indicate they may have fallen even further — more than 30 percent between 1987 and 1990. FDA's recent approval of several new ventilators and two kinds of surfactant to treat RDS has contributed to premature infants' chances of survival.

Lubricating Lungs

Short for "surface-active agent," a pulmonary surfactant is perhaps the most beneficial new treatment RDS patients like Benjamin can receive. FDA has approved two kinds of surfactant, the first in July 1990 and the second a year later.

A pulmonary surfactant is a foamy liquid produced naturally in human and animal lungs. It reduces the surface tension between the wet lung tissue and dry air to keep the tiny air sacs in the lungs, called alveoli, from collapsing between breaths.

Without lung surfactant, every breath requires tremendous force, like blowing up a new balloon.

Because surfactant production is one of the last processes a fetus develops in the womb, preterm infants often don't have it. Commercially prepared surfactants replace the missing natural lung surfactant until the infant can produce his or her own a few days after birth.

"Surfactant has made a dramatic difference in the survival of very-low-birthweight infants," says Dr. K.N. Siva Subramanian, the chief of the Division of Neonatology at Georgetown University Hospital in Washington, D.C.

Georgetown has been using a surfactant in clinical trials for more than three years, and doctors say babies who get it require less intensive medical care and less time on ventilators because of it.

The first FDA-approved surfactant was Exosurf Pediatric, a synthetic compound made by Burroughs Wellcome Co. of Research Triangle Park, N.C. The second approved surfactant, Survanta, is a compound made from cow lungs. It was developed in Japan and is distributed by Ross Laboratories of Columbus, Ohio.

Both drugs are passed down the infants' lungs through a ventilator tube. They can be given as "rescue" treatments to babies who have already developed RDS, or "prophylactic" (preventive) treatments to infants at risk of developing RDS.

In either case, studies show that surfactants reduce RDS deaths by about half. They also shorten the time infants need to be on ventilators.

Pulmonary surfactant has been a lifesaver to children born unexpectedly early. It has also given hope to parents who know their unborn children are at high risk for prematurity.

For example, in 1990, Leslie and Matthew Carter of Carmel, Ind., chose to have their children at the Indiana University Medical Center in part because they knew the hospital had surfactant.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.