Cooling blankets may reduce newborn brain damage
BY RONI RABIN
STAFF WRITER
October 12, 2005, 8:22 PM EDT
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, which usually ranges from 99.7 degrees to 99.3 degrees.
The study of 208 infants at 15 medical centers was reported by
researchers in the Neonatal Research Network of the National 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 also urged caution, saying further research is
necessary and warning that most hospitals should not attempt to the
technique without training of personnel.
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 babies born 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 who received the cooling treatment fared better than babies
provided with standard treatment. Of the 208 babies in the study, 102
infants 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 of the
babies who received the standard treatment had died or developed a mild
or severe disability, compared to 44 percent of those who had the
cooling treatment. When all three outcomes -- death, moderate disability
and severe disability -- were pooled, findings were statistically
significant.
Among those who were cooled, 24 died, compared with 38 deaths in the
control group.
Fifteen infants who had the experimental treatment developed cerebral
palsy and five went blind, compared with 19 and nine, respectively, of
thosee who had standard care.
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 years old.
Several other studies investigating the benefits of cooling treatment
are under way. Researchers at Schneider Children's Hospital in New Hyde
Park have participated in a study that used a cooling "cap" to mitigate
brain damage in newborns similarly afflicted by oxygen deprivation, and
other studies are under way in Australia and England.
"They key thing is that the cooling, whether by blanket or by cap, helps
some babies," said Dr. Andrew Steele, a neonatologist at Schneider
Children's Hospital involved in the cooling cap study.
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 actually reducing the swelling of brain cells.
"It is a very promising, evolving therapy, but there's a lot more work
to be done, alot of questions still to be answered," said Dr. Ann Stark,
chair of the American Academy of Pediatrics Committee on the Fetus and
Newborn Health.
Copyright 2005 Newsday Inc.
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