Published: Sept. 18, 2002
Updated: Nov. 3, 2004
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By Duke Medicine News and Communications
DURHAM, N.C. -- Duke University Hospital will begin enrolling patients in a national study to test whether maintaining a cool body temperature in brain injury patients who are already hypothermic when they arrive at the hospital substantially improves their outcome. Duke is one of nine medical centers nationwide that will take part in the National Acute Brain Injury Study: Hypothermia II, a $15.6 million project sponsored by the National Institutes of Health.
"The classic outcome for a patient with traumatic brain injury is death or severe disability," said Carmelo Graffagnino, M.D., a neurologist and lead investigator of the study at Duke. "The societal implications are tremendous because most people who sustain this type of injury are in the prime of their lives. There are steps we can take to improve treatment and outcomes, but we need to make sure they are safe by conducting this type of research."
The national study is being led by Guy L. Clifton, M.D., chair of the department of neurosurgery at the University of Texas Health Science Center at Houston. In the first National Acute Brain Injury Study (NABIS), which began in 1994, Clifton and other researchers found that inducing hypothermia in patients with severe head trauma did not have the therapeutic value that scientists expected. However, 30 percent of patients in that study were already hypothermic when they came to the emergency room. In that group, maintaining hypothermia appeared to improve their outcome. Forty-eight percent of those patients who were kept cold for a period of time had a good outcome and were able to live independently. By contrast, only 24 percent of the hypothermic patients who were re-warmed had significant recovery. The results of the five-year study were published in the Feb. 22, 2001 issue of the New England Journal of Medicine.
To be enrolled in this study, patients must be 16 to 45 years old, have a closed head injury and hypothermia, and be comatose upon arrival at an emergency room. They also must have no other significant injuries. Half will be placed in temperature-controlled suits, which were invented and designed by UT-Houston researchers.
The Rap Round suits, manufactured by Gaymar Industries, allow doctors to precisely control and maintain their patients' body temperatures at 33 to 37 degrees Celsius (91.4 to 98.6 degrees Fahrenheit). After 48 hours, doctors will gradually re-warm the patients during an 18-hour period.
The other patients will re-warm by themselves with no medical intervention to raise their body temperature.
"We believe that rapid re-warming, which is currently the standard of treatment, may actually be toxic to the brain," said Clifton. "We will be looking at whether it is better to let them passively re-warm or maintain hypothermia."
Patients must be enrolled in the study before they start to re-warm because "there are grave implications if you do not act immediately to treat the head injury," Graffagnino said.
Because of this, researchers plan to waive consent if a family member cannot be located within one hour of the patient's arrival at the hospital. To be in compliance with federal law and the Internal Review Board at Duke University Medical Center, researchers are making presentations in the community to inform residents about the study and explain the waiver-of-consent issue. The 1994 NABIS was the first study to test whether waiver of consent was effective and met with community approval.
Roughly 1.5 million Americans suffer traumatic brain injury (TBI) each year. About 50,000 die and another 80,000 of these patients are permanently disabled. An average of 30 percent of those patients are hypothermic when they arrive at the hospital. Hypothermia is often the result of cold weather, intoxication, small body type or cold intravenous fluids that are administered at the scene of injury.
"Hypothermia has been of medical interest for years because we can see that it works far better than drug therapy in animal models," said Graffagnino. "Duke's intensive care unit is uniquely suited to participate in this research because we have a multidisciplinary team that is very well practiced in the care of patients with TBI."
Duke researchers will hold their first community educational sessions at 6:30 p.m. on Sept. 23 at the Chapel Hill Public Library, and at 7 p.m. on Sept. 26 at the Talley Student Center on the campus of North Carolina State University in Raleigh. Additional educational sessions are planned but not yet scheduled.
Other study sites are the University of California, Davis; the University of California at San Francisco; the University of Southern California; the University of Pittsburgh Medical Center; Inova Fairfax Hospital; the University of Mississippi and UT-Houston.