Low oxygen supply to the brain increases the risk of major disability or death after severe traumatic brain injury, new research shows.
The results of this study, led by Dr. Mauro Oddo, of the University of Pennsylvania Medical Center in Philadelphia, support a revision to guidelines calling for brain oxygenation monitoring during intensive care for patients suffering from severe head injury.
Researchers looked at how brain hypoxia (low oxygen supply) affected clinical outcomes in 103 patients with TBI. Most of the patients had bleeding within the brain after severe, blunt head trauma. In addition to sensors placed for routine monitoring of pressure within the skull and brain blood flow, all patients underwent monitoring of brain oxygenation.
Patients were considered to have brain hypoxia if their oxygen supply fell below a certain critical level. Of the patients included in this study, 43 percent had poor outcomes which resulted in death, survival with severe disability or survival in a vegetative state.
The greater the decrease in brain oxygenation, the greater the risk of poor outcomes. The average duration of time with brain hypoxia was 8.3 hours for patients with poor outcomes after TBI, compared to 1.7 hours for those with good outcomes, which included survival with no or moderate disability.
High intracranial pressure is typically seen as a bad prognostic sign for patients with TBI. Among the patients in the study with high intracranial pressure, only 46 percent of those with brain hypoxia had good outcomes, compared to 81 percent of those without brain hypoxia.
Brain oxygenation was also a stronger outcome predictor than cerebral perfusion pressure. Some patients had good brain oxygenation, despite reduced brain blood flow, while maintaining the recommended levels of cerebral perfusion pressure was sometimes insufficient to avoid low brain oxygenation.
After adjusting for these and other risk factors, brain oxygenation was a significant predictor of patient outcomes. For each extra hour with brain hypoxia, the risk of poor outcomes increased by 11 percent.
The study’s findings support the recent changes that add brain oxygen monitoring after severe TBI, as part of an integrated monitoring strategy. However, the study’s authors say more research is needed to determine if treatment adjustments in response to brain oxygenation monitoring result in any positive change in patient outcomes.
For more on traumatic brain injury, see the library of articles by Daytona Beach car accident attorney.