Vegetative State May Be Caused by Brain Cooling, New Study
Widespread Use of Cold Air In Breathing Tubes May Prevent Recovery of Brain Injured Patients
Springfield, IL (June 28, 2006) — The odds of recovery from brain injuries and vegetative states may be dramatically improved simply by restoring normal brain temperatures, according to a new medical theory published in the July issue of Medical Science Monitor.
The study was inspired by the case of 53-year-old woman who suffered a heart attack and oxygen deprivation to the brain. In the course of a few days slipped from consciousness to coma to a vegetative state. For the following thirty-one months she was receiving oxygen through a tube in her trachea.
But then one day it was noticed that the oxygen in the tube was over thirty degrees below body temperature. Acting on the speculation that such chilled air could not be good for the patient, the tube was removed. One month later, the woman came out of the vegetative state and was verbal and able to respond to questions.
Inspired by this case, the authors began to investigate the physiological link between lung temperatures and brain temperatures. They found that chilled tracheal air will produce chilled aortic blood which will in turn produce a significant drop in brain tissue temperatures.
Because the path from the aorta to the brain is short, a drop in brain temperatures may occur even though the core body temperature otherwise appears to be normal. But even a small drop in the brain temperatures can produce important deviations in neurochemistry and the endocrine system. These changes, the authors suggest, may not only inhibit recovery but may even produce additional problems.
To access the potential impact of their findings, the authors also surveyed a sample of hospitals and nursing homes. Most health care facilities reported they do not heat the oxygen given to non-responsive, intubated patients.
The authors suggest that paying closer attention to intubated air temperatures, or removing intubation tubes as soon as practical, would pose no risk to patients and may well produce a significant increase in the rate of recovery from brain trauma. They also propose numerous strategies for future research.
Ford GP, Reardon DC. Prolonged unintended brain cooling may inhibit recovery from brain injuries: case study and literature review. Medical Science Monitor 12(7), 2006.