Low Oxygen Linked to More Fatalities After Brain Injury

Severe traumatic brain injury outcome negatively impacted by low oxygen levels

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) For patients with severe traumatic brain injury, a low supply of oxygen to the brain following the injury carries substantial risk. It can significantly contribute to death or disability, a recent study shows.

This finding suggests that revision of a guideline mandating monitoring of oxygen to the brain for intensive care patients with a severe head injury may help.

"Head to the hospital immediately after a suspected brain injury."

Dr. Mauro Oddo of the University of Pennsylvania Medical Center noted that low oxygen levels were linked to poor short term outcomes following a severe traumatic brain injury, regardless of other factors such as blood flow to the brain or intracranial pressure.

During the study, researchers monitored 103 patients with traumatic brain injury to determine how low oxygen affected their brains. The majority of the patients had bleeding inside the brain after severe blunt trauma to the head.

Investigators used sensors to monitor intracranial pressure and brain blood flow. They also monitored the amount of oxygen reaching the brain, and determined which patients had brain hypoxia when their oxygen supply fell below a critical level. Of the patients monitored, 43 percent died, or survived with a severe disability or in a vegetative state.

The greater the oxygen deprivation, the higher the risk of a negative outcome. The average length of time with brain hypoxia was 8.3 hours for patients with poor outcomes after  injury versus 1.7 hours for those with good outcomes.

Among those found to have high intracranial pressure, 46 percent of patients with low oxygen had good outcomes compared to 81 percent of those without brain hypoxia.

After adjustments, brain oxygenation was found to be a significant predictor of outcomes. For each additional hour with brain hypoxia, the risk of a poor outcome increased by 11 percent.

Additional research is needed to determine whether adjusting treatment in response to low oxygen levels could lead to improvements in the patient outcomes.

The clinical study was published in the November issue of Neurosurgery, the official journal of the Congress of Neurological Surgeons.

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Review Date: 
November 10, 2011
Last Updated:
November 13, 2011