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Cooling cap could stop brain damage

A new device may lessen injuries in newborns deprived of oxygen.

June 07, 2004|Linda Marsa | Special to The Times

Every year, thousands of newborns are deprived of oxygen during delivery. The brain damage that often results can't be reversed, and many of these infants die or are severely disabled.

An experimental head-cooling device may be able to prevent or reduce some of these brain injuries, enabling more babies to lead normal lives.

Called a CoolCap, the appliance works by circulating cold water inside a thin plastic cap, which is covered by a cloth hat that fits snugly around the infant's head. The water temperature is slowly lowered to 50 to 59 degrees Fahrenheit, cooling the baby's body temperature to 94 degrees.

Doctors aren't sure why cooling the body seems to prevent or reduce neurological injury. They theorize that lowering the body temperature slows brain metabolism, which reduces the body's need for oxygen. It also may dampen the immune system's response to the initial injury, which decreases brain swelling and inflammation, stops or slows the release of potentially harmful toxins and helps prevent brain cell death.

"This therapy looks extremely promising and may really help thousands of infants," says Dr. Richard A. Polin, a pediatrician at the Columbia University College of Physicians and Surgeons in New York who has tested this device.

In one to two of 1,000 births, a newborn's blood flow or oxygen supply is cut off during labor or delivery. This serious complication, which can afflict as many as 8,000 of the 4 million children born in the U.S. every year, occurs for several reasons: The mother's uterus can rupture or the umbilical cord can become compressed or tangled around the baby's neck or arm. The affected babies are comatose or extremely lethargic at birth, and they have difficulty breathing.

By the time they're born, the brains of some have been severely injured. Others are at risk for what doctors call a secondary injury, in which the immune system response -- swelling and inflammation -- can cause damage.

"Right now we have nothing to offer them, and many of these kids end up having long-term handicaps, like cerebral palsy, mental retardation and seizures," says Dr. John Barks, a pediatrician at the University of Michigan Medical School in Ann Arbor who has studied the experimental treatment.

Results of a recent test of the CoolCap were encouraging. The international trial, which was conducted between 1999 and 2003 at 28 centers in the United States, New Zealand, Canada and Great Britain, involved 218 babies. Brain wave tests were used to determine the degree of initial injury at the time of birth. Within five hours of their delivery, half of the newborns were fitted with the CoolCap, which they kept on for 72 hours. The remainder received only the standard newborn intensive care treatment.

The infants had neurological and developmental tests 18 months later to evaluate their motor skills and mental abilities. The most severely damaged showed no benefit from the treatment. However, the rates of death or disability in moderately injured infants dropped from 66% to 48%. And in newborns with mild to moderate injury, mortality rates dropped from 39% to 25%, and only 11% of these CoolCap babies sustained severe motor disability, such as cerebral palsy, compared with 27.8% in the control group.

CoolCap's maker, Olympic Medical Corp. of Seattle, hopes to have the device approved for use on full-term babies by the end of the year. "We're very happy with the results of the study," says Polin. "This is the first proven therapy to treat this condition."

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Life-giving chill

An alternative way of cooling oxygen-deprived newborns is being tested at 17 medical centers in the U.S.

In the study, funded by the National Institutes of Health, infants are placed on a specially designed blanket that chills their entire body to 92 degrees Fahrenheit for 72 hours. Results of the test, which involved 208 newborns, will be available in December.

"We now know that cooling is protective, which is very exciting," says Dr. Seetha Shankaran, a neonatologist at the Wayne State University School of Medicine in Detroit and the lead investigator for the study. "Now we're trying to find the best method."

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