Today I came across an article by Choi et al. highlighting the use of Targeted Temperature Management (TTM), which is therapeutic cooling of the body (induced hypothermia), as a way for treating acute brain injury as well as preventing extensive neural damage. While I was already aware of it’s use in the acute treatment phase in hospitals, I was unaware of it’s effects for different aspects of brain injury and exactly how it was implemented. TTM has been deemed the “most powerful mechanism of neuroprotection currently available”.

TTM seems to work by decreasing the brain’s metabolism, limiting oxygen uptake, thereby preventing the failure of many neural mechanisms involved in cellular metabolism. By reducing the amount of oxygen required, we are reducing the action of sodium and potassium pump (NaKATPase) to decrease the need of ATP (which is made using oxygen via cellular metabolism). Often times, traumatic brain injury (TBI) can cause bleeding in the brain, which can lead to decreased oxygen levels in the blood, causing neural damage. Therefore, TTM is an amazing invention, enabling an injured brain to still function even if there is a brain bleed (depending on severity). There are numerous severe dangers in conducting such a procedure, such as shivering, kidney dysfunction, immune function impairments to name a few. However, despite these dangers, it seems as though the benefits severely outweigh the negatives as it can prevent death in some cases.

Some conditions where TTM is most commonly used include ischemic stroke, TBI and cardiac arrest. Choi outlines these numerous conditions and highlights their effectiveness.

Cardiac arrest results in a stoppage of blood-flow to the brain, leading to wide-spread damage. When someone’s heart starts beating again, you get a rapid perfusion of the brain, which, despite bringing back the much-needed oxygen, can cause additional damage. It does seem that TTM down to anywhere between 32-34 degrees Celsius for 24 hours is significantly beneficial. For TBI, TTM seems to be ineffective, however, Choi hypothesizes some reasons why such studies have been unsuccessful, and proposes a few ideas for how such studies could be improved. In the case of ischemic stroke, where there is a blockage of blood-flow to the brain (either due to a embolism or plaque build-up), TTM is a feasible approach. By decreasing the amount of blood required by the brain, it reduces the damage until the embolism or plaque can be cleared.

Despite not being effective for certain conditions, it seems as though TTM being implemented into emergency and critical care medicine is beneficial, and should obviously continue to be used.

 

Works Cited:

Choi, H. Alex, Neeraj Badjatia, and Stephan A. Mayer. “Hypothermia for Acute Brain Injury–Mechanisms and Practical Aspects.” Nature reviews.Neurology 8.4 (2012): 214.

URL: http://www.nature.com.ezproxy.library.ubc.ca/nrneurol/journal/v8/n4/full/nrneurol.2012.21.html