By Brenda L. Mooney
MINNEAPOLIS—The combined use of hyperbaric oxygen and normobaric hyperoxia therapies provides better outcomes in patients with severe traumatic brain injury (TBI) than the standard intensive neurosurgical care recommended for this injury, according to a new study.
The study from researchers at the Hennepin County Medical Center, University of Minnesota, and Minneapolis Medical Research Foundation in Minneapolis was published online by the Journal of Neurosurgery.
“The enormous negative social and economic impact of TBI throughout the world cannot be overemphasized,” the authors write. “The major issue is premature death and disability both in civilian and military populations.”
While in hyperbaric oxygen (HBO2) therapy, patients are placed in a pressure chamber set at an atmospheric pressure higher than normal and given pure oxygen, in normobaric hyperoxia (NBH) therapy, patients receive pure oxygen at normal atmospheric pressure.
The research was designed to test the hypothesis that the combination of the therapies, both of which have been suggested as treatment for severe TBI, would produce even better outcomes.
In the clinical trial, 42 patients with severe TBI (Glasgow Coma Scale score of 8 or less) were randomly assigned to one of two treatment groups within 24 hours after injury. The control group of 22 patients received standard intensive neurosurgical care prescribed for severe TBI, including endotracheal intubation and stabilization of the patients’ condition in the emergency department, surgery to remove significant hematomas, continuous monitoring of intracranial pressure (ICP), and treatment of ICP if intracranial hypertension developed. All patients also received phenytoin sodium to prevent potential seizures.
The intervention group of 20 patients received hyperbaric oxygen therapy followed by normobaric hyperoxia treatment in addition to standard care, receiving the combined HBO2/NBH treatment while in a pressure chamber. Pure oxygen was delivered at 1.5 times normal atmospheric pressure (hyperbaric oxygen [HBO2] therapy) for 60 minutes and was followed by additional hours of pure oxygen delivery at normal atmospheric pressure. The combined treatment took place every 24 hours over a three-day period.
The group of patients who received the combined HBO2/NBH treatment fared better overall than the group of patients who received standard care, according to study authors. They note that, in comparison between the two groups, the combined HBO2/NBH treatment
- reduced the mortality rate and improved the rate of favorable outcomes (measured by applying the Glasgow Outcome Scale six months after treatment)
- improved markers of cerebral oxidative metabolism in areas of the brain that were relatively undamaged as well as in the region of injury
- reduced intracranial hypertension and, consequently, reduced the intensity of treatment needed to lower intracranial pressure
- did not create oxygen toxicity in the brain or lungs, which can occur when excessive amounts of oxygen are present
- effected greater improvements in clinical outcomes than have been observed in previous studies in which HBO2 or NBH treatment was used alone
“Although the number of patients in this trial was relatively small, the improvement in neurological recovery was dramatic—better than outcomes of previous treatments for traumatic brain injury,” said co-author Gaylan Rockswold, MD, PhD. “We are pursuing funding for a larger randomized clinical trial from NIH to further evaluate this treatment for TBI.”