Lowering body temperature can aid newborns


NEW YORK -- Lowering a newborn's body temperature after birth reduces risk of brain damage and death for babies who are deprived of oxygen before or during delivery, a new study has found.

Within hours of being born, newborns in the study were placed on cooling blankets that lowered their body temperature to about 92 degrees. The blankets, which had water circulating through them, were set at 41 degrees. After three days, the babies were gradually warmed to a normal body temperature.

The study of 208 infants at 15 medical centers was reported by researchers in the Neonatal Research Network of the Institute of Child Health and Human Development, and appears today in The New England Journal of Medicine.

"This is a very exciting, landmark study," said lead author Dr. Seetha Shankaran, head of the division of neonatal-perinatal medicine at Wayne State University School of Medicine in Detroit.

But the sponsors urged caution, saying further research is needed. They also warned that hospitals should not attempt the technique without proper training.

The babies must be closely monitored, and strict protocols must be followed because temperature fluctuations could be harmful, the study authors said.

One in every 1,000 to 2,000 newborns suffers from hypoxic ischemic encephalopathy, which occurs when the brain doesn't get enough oxygen or blood in the hours before birth or during labor and delivery. These babies are at markedly increased risk of disability, including blindness and cerebral palsy, as well as death.

Babies deprived of oxygen who received the cooling treatment fared better than those provided with standard treatment. Of the 208 in the study, 102 were randomly assigned to undergo the experimental cooling while 106 received standard care.

When the babies were examined at 18 to 22 months, 62 percent who received the standard treatment had died or developed a mild or severe disability, compared with 44 percent of those who had the cooling treatment.

Infants who received the cooling treatment also scored better on mental and physical development measures, the authors said. The children will be followed until they are 6 or 7.

Shankaran explained that when the brain is deprived of oxygen and blood, a cascade of abnormal events occurs, including formation of toxins and amino acids that damage brain cells. Cooling appears to work by reducing the energy of the brain itself, she said, thereby decreasing the abnormal toxins and reducing the swelling of brain cells.

"It is a very promising, evolving therapy, but there's a lot more work to be done, a lot of questions still to be answered," said Dr. Ann Stark, chair of the American Academy of Pediatrics Committee on the Fetus and Newborn Health.

Roni Rabin writes for Newsday.

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