New drug helps tiny infants breathe a little easier


September 10, 1990|By Jean Marbella

Five years ago, Jacky McCoy watched in horror as nurses and doctors worked on a tiny baby born after less than 24 weeks of the normal 38 weeks of pregnancy.

"They'd have to bang on him to loosen up the mucus that develops on the lungs. Then they'd have to suction out the

lungs," she recalled with a slight shiver. "And he had to go home with an oxygen pack, his mother had to carry it everywhere she went."

Her own baby was also premature, but at 29 weeks big enough not to require such measures. Yet this February, Mrs. McCoy found the memories flooding back as she gave birth to her third child -- who arrived at 24 weeks, gasping for air with woefully underdeveloped lungs.

But unlike that baby she remembered from years ago, her son Michael "is blessed, really blessed."

Indeed, the 1-pound, 5-ounce Michael McCoy had a less rude awakening to life, thanks to a recently approved drugthat is proving a lifesaver to these smallest and most vulnerable of babies.

Just six months ago, family photographs show, this bright-eyed and wriggling infant had the wizened look of many premature babies, his papery-dry skin stretched tightly over a tiny frame, his birdlike bones and even blood vessels readily visible through the translucence of his fragile shell.

Of all the problems such preemies face, respiratory distress syndrome is the one that will most likely kill or disable them. Of the 250,000 infants born prematurely each year, about 50,000 have respiratory distress syndrome and about 5,000 ultimately die of it.

The reason, in many cases, is that very premature babies are born without a vital substance called surfactant, a foamy coating that lines the lungs and keeps them from collapsing when air is exhaled.

Some 20 years of research to come up with a surfactant substitute paid off on Aug. 6, when the firstsuch formulation won Food and Drug Administration approval. Sold under the trade name of Exosurf by Burroughs Wellcome Co., this synthetic surfactant is the first of several that manufacturers hope will also receive FDA approval in the future.

"It's a major breakthrough," said Dr. Ira H. Gewolb, chief of neonatology at University of Maryland Hospital. "These surfactants clearly are going to help in the saving of babies."

"At least one-fifth to one-fourth of the babies we see could benefit from this," said Dr. Ambadas Pathak, head of newborn medicine at Greater Baltimore Medical Center. "It's a significant breakthrough. I'm very encouraged."

Theirs were among several hospitals in the area and 400 nationwide that used the drug on an investigational basis before approval. Some 10,000 babies have received the drug in the past year, for free, in a move to make life-saving drugs available before the FDA approves them for general use.

In earlier clinical trials of Exosurf, the drug was found to reduce death from respiratory distress by 50 to 66 percent, depending on how it was used and the size of the baby. Possible side effects include an increased chance of pulmonary bleeding in very small babies and apnea, the temporary cessation of breathing.

Local hospitals report fairly successful use of the drug. At GBMC, for example, 13 babies treated with Exosurf survived, five did not, Dr. Pathak said. (Of those five, three hadother complications that contributed to their death; one, for example, was only 23 weeks gestational age, and another had cardiac problems, he said.)

The risks of taking an as-yet-unapproved drug now seems well worth it, said Mark Chapman, whose daughter Krista was the first baby at GBMC to receive the drug when she was born 2 1/2 months prematurely in November.

"We were terrified, but what were our choices? Had she not gotten the drug, she wouldn't be here today," Mr. Chapman, a restaurant manager, said with certainty. "I have no regrets. All you have to do is look at her now."

Indeed, the active Krista seems quite happy to be here -- she resists the idea of sitting still, instead grabbing at anything within reach and looking with obvious curiosity at the world around her.

Her mother, Ingrid, a bank teller, was six months pregnant when her water broke prematurely. An infection set in, and when it threatened both their lives, doctors delivered the baby even though she was just 26 1/2 weeks gestational age.

"She was this big," Mr. Chapman said, holding up a palm. "She was like a little dried-up old woman."

At one point, the infant's weight dropped to just 1 pound, 10 ounces.

While premature babies are underdeveloped in just about every way, their lungs are most critically so because they are among the last of the major organs to mature.

Without surfactant, the air sacs in the lungs collapse when the baby exhales instead of maintaining their shape and keeping in some of the inhaled air. Breathing becomes increasingly difficult as the baby has to work harder to fill the lungs with air, and the lungs themselves become stiff rather than pliant.

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