The way we cool patients and especially those with severe brain injuries
has traditionally been with surface cooling techniques--cooling blankets.
In addition, we may apply ice packs in the axilla, under the armpits, or in the groin areas
where there's a great deal of blood flow so that you can affect the blood
and cool the blood more quickly.
More recently, in children and especially in babies,
people have been using cooling helmets, if you will, or cooling caps
where they put plastic caps around the head of the infant
and circulate cold water through those helmets.
And even more recently, we've developed devices where we can
insert intravenous catheters with a closed circuit system
where we can circulate ice water through sausage-shaped balloons on those catheters.
And so as the blood passes by those balloons, the blood is cooled,
and that seems to be, at least to date,
the most effective or most efficient way of cooling people quickly.
[How long is a person cooled?]
Several of us, including myself and Guy Clifton,
years ago sort of arbitrarily decided that we would just cool for 24 to 48 hours.
We did that because of two things.
One, we thought that the maximum degree of metabolic change in the brain after trauma
was during that first day or so after injury, which is what we were going after.
And secondly, we knew that the longer you cool, the greater the possibility
the patient was going to develop an infection or a pneumonia.
The investigators in Japan have used hypothermia for as long as necessary
in order to keep the intracranial pressure low.
So in some of their studies, Shiozaki for one and Higashi for another,
they have taken cooling out to as long as 2 weeks.
But if you look at their clinical trials, their rates of pneumonia are double or triple
what they had been for Dr. Clifton and my studies.
[What are the risks with hypothermia?]
The risks associated with hypothermia
are actually pretty minimal and pretty clinically insignificant.
They depend on the intensity of cooling or how low you take the temperature.
It also depends on how long you cool the individual.
So we know that hypothermia does suppress the immune response of the body.
Even simple things like clearance of secretions in the lungs are slowed,
and so you're more prone to a pneumonia the longer you're cooled.
We also know that the most severe complications of hypothermia are seen
only when temperature drops below 85 degrees Fahrenheit.
Show transcript | Print transcript
Cooling people who have sustained a brain injury is not new therapy. But, it is getting more advanced, and the risks are minimal.
Produced by Noel Gunther and Brian King, BrainLine.
Donald Marion, MD, MSc is director of Clinical Affairs, The Defense and Veterans Brain Injury Center, and contractor with the Henry M. Jackson Foundation for the Advancement of Military Medicine. He is an academic neurosurgeon who has focused on the clinical pathophysiology and treatment of traumatic brain injury for more than 25 years.
The contents of Brainline (the “Web Site”), such as text, graphics, images, information obtained from the Web Site’s licensors and/or consultants, and other material contained on the Web Site (collectively, the “Content”) are for informational purposes only. The Content is not intended to be a substitute for medical, legal, or other professional advice, diagnosis, or treatment.
Specifically, with regards to medical issues, always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Web Site. If you think you may have a medical emergency, call your doctor or 911 immediately. The Web Site does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Web Site. Reliance on any information provided by the Web Site or by employees, volunteers or contractors or others associated with the Web Site and/or other visitors to the Web Site is solely at your own risk.