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Introduction
Hypothermia is a medical condition that occurs when your core body temperature drops
beneath 36.1 degrees Celsius (Cold Environments ...[updated October 2, 2008]). As their
temperature lowers it can cause the person to lose consciousness, you may not be able to
feel their pulse, and may appear if their core temperature continues dropping. Even if a
person with hypothermia appears dead they can still be revived if handled and warmed
properly.
Different tests have been done over the years that show both in animals and people that
lowering the core temperature to around 32-33 degrees Celsius can lower a person’s heart
rate and intercranial pressure (ICP). This has been shown to help in the treatment of
severe non-penetrating head injuries. Although different experiments were done, the ones
that will be used for this work include two by Clifton in (1993, 2001) and the one by
Marion, (1997). Two of them show hypothermia being effective in if used along with the
regular treatment for this type of injury; however in the larger of the two studies by
Clifton results indicate that there is no difference.
In all of the studies used the
patients where in comas and
had scores of 3~8 in the
Glasgow Coma Scale. The
GSC works by assigning each
characteristic of a coma a
number, and it being
seppareted by eye, verbal, and
motor responses, then adding
them all. The table above
shows the different
characteristics in each of the
groups, as you can see the
highest score means the better

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condition, and is a score of 15, while the worst is a 3, in which no responses are show at
all.
Experimental Evidence
Clifton’s first work in 1993 showed that in a test with 46 patients, that 16% more of the
hypothermia group, consisting of 24 patients, had a successful recovery, while 8 of them
died, also 8 out of the 22 normothermia (normal body temperature) group patients died.
In Marion’s study (1997) 62% and 38% of the hypothermia and normothermia groups
had a successful recovery (scores of 4-5 in the Glasgow Outcome Scale [GOS], seen
below) after 12 months.
http://www.neurocirugia.com/escalas/GOS.htm (translated)
It was also found that Clifton’s first test and in Marion’s the hypothermia group
had less incidents of seizures or other complications, however in Clifton’s second neither
group had seizures, and all the tests showed that the hypothermia group had less ICP and
neurotoxins. Below are two tables, the one on the left showing patient information for
Clifton’s second test, and the right one of Marion’s. These tables show that both groups,
in each test, are very similar in terms of injury and age, and the patients in both tests are

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of similar ages.

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http://nejm.highwire.org/content/vol344/issue8 http://content.nejm.org/content/vol336/i
/images/large/03t1.jpeg ssue8/images/large/03t1.jpeg
Current understanding
The results from the first two experiments (Clifton et al. 1993, Marion et al. 1997)
conflicts with the results from the most recent (Clifton et al. 2001), seeing in the latest
both groups had very similar results, both in general outcome and in deaths. Other

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information that has been observed in the hypothermia group agrees with each other, for
example: lower ICP, less neurotoxins, and fewer seizure incidents
Controversy
As stated before in both of the small clinical trials (less than 90 patients each) the
hypothermia group showed much better end results than the normothermia group
although the temperatures differed by some degrees. However, the larger test 392
patients, shows evidence that hypothermia may not help patients. According to the multi-
clinical test by Clifton (2001), patients in the hypothermia group spent more time in the
hospital and required more medications to maintain stabilized. According to Grände
(2009) if you only look at the bigger trails that have done hypothermia treatment seems to
be more damaging than normal therapy
Conclusion
After analyzing the available literature the benefit of hypothermia on patients
with severe non-penetrating head injuries it is not clear. More tests are needed in this
research area in order to prove, or disprove, the usefulness of hypothermia and the
otherwise regular therapy on patients with severe non-penetrating head injuries. Different
tests have shown conflicting results, larger tests have said that hypothermia is not a good
method, where as smaller tests say they are. The difference might be caused by the
difference in the persons regular temperature varying in the place where they were

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treated, also in Clifton's second study the patients in the hypothermia group were
reheated slower than in the other two tests.
Citations:
Adelson P. D. 2009. Hypothermia following Pediatric Traumatic Brain Injury,
Journal of Neurotrauma [Internet]. [Cited 2009 Dec 17] 26(3): 429-436. Available from:
http://www.liebertonline.com/doi/abs/10.1089/neu.2008.0571?
url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dncbi.nlm.nih.gov
Clifton, G. L., Allen, S., Barrodale, P., Plenger, P., Berry, J., Koch S., Fletcher, J.,
Hayes, R. L., Choi, S. C. 1993. A Phase II Study Of Moderate Hypothermia In Severe
Brain Injury, Journal Of Neurotrauma [Internet]. [Cited 2009 Dec 17] 10(3): 263-271.
Available from: http://www.ncbi.nlm.nih.gov/pubmed/8258839
Clifton, G. L., Miller, E. R., Choi, S. C., Levin, H. S., McCauley, S., Smith, K. R.,
Muizelaar, P., Wagner, F. C., Marion, D. W., Luerssen, T. G., Chesnut, R. M., Schwartz,
M. 2001. Lack of Effect of Induction of Hypothermia after Acute Brain Injury, The New
England Journal of Medicine [Internet]. [Cited 2009 Dec 17], 344:556-563. Available
from: http://nejm.highwire.org/cgi/content/full/344/8/556#R5
Cold Environments- Health Effects and Frist Aid [Internet]. Canadian Center for
Occupational Health and Safety; [Cited 2009 Dec 18]. Available from:
http://www.ccohs.ca/oshanswers/phys_agents/cold_health.html
Glasgow Coma Scale (GCS) [Internet]. [updated July 30, 2001] University of
Northen Carolina; [cited 2009 Dec 18]. Available from:

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http://www.unc.edu/~rowlett/units/scales/glasgow.htm
Glasgow Outcome Scale [Internet]. Neurocirugia; [Cited 2009 Dec 18]. Available
from: http://www.neurocirugia.com/escalas/GOS.htm
Grände PO, Reinstrup P, Romner B. 2009. Active cooling in traumatic brain-
injured patients: a questionable therapy?, Acta Anaesthesiol Scand. [Internet]. [Cited
2009 Dec 17] 53(10): 1233-8
Hypothermia [Internet]. Survive the Outdoors Inc.; [cited 2009 Dec 18].
Available from: http://www.surviveoutdoors.com/reference/hypothermia.asp
Marion, D. W., Penrod, L. E., Kelsey, S. F., Obrist, W. D., Kochanek, P. M.,
Palmer, A. M., Wisniewski, S. R., DeKosky, S. T. 1997. Treatment of Traumatic Brain
Injury with Moderate Hypothermia, The New England Journal of Medicine [Internet].
[Cited 2009 Dec 17] 336: 540-546. Available from:
http://content.nejm.org/cgi/content/abstract/336/8/540