Hypothermia For Concussions + A Possible Delivery Device


The old adage of the profession of athletic training is “ice er’ down”.  This comment is both simple and can seem to the patients/parents/coaches that you are not doing enough.  However I am here to tell you that hypothermic treatment (ice) is EXTREMELY beneficial for just about every* injury we see for the basic principle of; slowing the metabolic response to injury.

When there is an insult to the body the immediate response is a metabolic reaction – in other terms the body uses chemical and mechanical pathways to repair/fix itself.  Although the reason for the metabolic response is thought to be for “repair” the body response is usually not limited to what is needed – the more is better philosophy.  I can bore you and make you click away real fast by giving you all the physiology of a metabolic response, so I won’t, but if you would like to read about it T.S. Walsh wrote a chapter in a book called “Principals of Surgical Care”.

Subsequent medical research has shown that attenuating the metabolic response has; decreased pain, shunted swelling, and improved outcomes, especially in a very narrow window after injury.  The least invasive and easiest way to accomplish this is via hypothermia (see heat related illness).  Cooling the body, even locally, can attenuate the metabolic response and the negative effects it has on recovery.  That is why you will hear athletic trainers tell you ad nausea to “ice ‘er down”.  The reason is simple we are helping you AND YOUR BODY recover faster.

*Don’t use ice if you have the following conditions: rheumatoid arthritis, Raynaud’s Syndrome, cold allergic conditions, paralysis, or areas of impaired sensation.

Logic would then tell you that because during a concussion there is a metabolic response (cascade), perhaps cooling will help with not only recovery but the attenuation of symptoms related to the brain insult.  In my humble opinion there is no “perhaps”, it does; not only have I seen this empirically with concussions I treat, but research suggests this with TBI’s;

Therapeutic hypothermia is a promising treatment for patients with severe traumatic brain injury (TBI). We present here the results of a study in which noninvasive selective brain cooling (SBC) was achieved using a head cap and neckband. Ninety patients with severe TBI were divided into a normothermia control group (n=45) and a SBC group (n=45), whose brain temperature was maintained at 33-35 degrees C for 3 days using a combination of head and neck cooling. At 24, 48 and 72h after injury, the mean intracranial pressure (ICP) values of the patients who underwent SBC were lower than those of the normothermia controls (19.14+/-2.33, 19.72+/-1.73 and 17.29+/-2.07 mmHg, versus 23.41+/-2.51, 20.97+/-1.86, and 20.13+/-1.87 mmHg, respectively, P<0.01). There was a significant difference in the neurological recovery of the two groups at the 6-month follow-up after TBI. Good neurological outcome (Glasgow Outcome Scale score of 4 to 5) rates 6 months after injury were 68.9% for the SBC group, and 46.7% for the control group (P<0.05). There were no complications resulting in severe sequelae. In conclusion, the noninvasive SBC described here is a safe method of administering therapeutic hypothermia, which can reduce ICP and improve prognosis without severe complications in patients with severe TBI.

There are other articles out there for various conditions and the usage of hypothermia that show the same results: better outcomes, 1072 articles in this search alone.

UPDATE: To continue with logic, the area of icing should not only encompass the head, but over the vessels that supply the brain with blood, carotid artery; thus the anterior/lateral parts of the neck.

Not only should we be applying ice to the head/neck of a possibly concussed athlete, we should be doing it yesterday – as in immediately upon revelation of the injury.  This is not only my opinion but also the opinion of Dr. Huan Wang who was awarded a grant to research the issue/feasibility of getting cool quick.  That study is being performed in my back yard and began in June, I will be anxiously awaiting the results.

==========

Employing this technique should not be an issue, but what can be an issue is how you do it.  Traditionally we have used the simple bag of ice (or bags) to accomplish the goals; it still works and seems to be the “gold standard” on the sidelines.  However technology and research may be catching up to develop a process by which a cool temperature is more sustainable for a longer time and delivered even more rapidly.

Thermopraxis thinks they may have a solution and seem to be on the same page;

Research has elucidated two distinct windows of opportunity for clinical use of hypothermia, a multimodal treatment. In the early intra-ischemic window, hypothermia modulates the downstream necrotic and inflammatory pathways, abnormal electrical brain activity, cellular free radical production, poor calcium management and poor pH management. In the more delayed post-reperfusion window, hypothermia modulates the downstream apoptotic – delayed cell death – and inflammatory pathways. The mechanisms of protection  – including reduction of cellular metabolism, maintenance of levels of ATP, reduction of enzymatic reaction rates, reduction of patterns of gene expression and protein production, improved ion management, and improved pH management support the concept that the efficacy depends on the time between ischemia/trauma onset and hypothermia induction.

Therapeutic hypothermia is not only a major field of investigation, it is an important development in the practice of emergency medicine.

In a recent phone interview with Thermopraxis President, Tony Finley, his passion for the advent of this technology is clear and “makes no sense as to why nothing has been accepted to this point.”  Their technology, which is gaining funding for a prototype seems to make sense.  Of course there are the practical hurdles of placing them in helmets: the accessibility of the delivery device, any possible compounding effects from pressure, etc., however Mr. Finley would like to “at least generate discussion on this topic.”

I suggest we do two things after my conversation with Mr. Finley: 1. start applying ice to the concussed, IMMEDIATELY (paying attention to any contraindications) and 2. discuss this technology.

I will be interested to see if the professional sports start doing this, make note…

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4 thoughts on “Hypothermia For Concussions + A Possible Delivery Device

  1. Luke September 9, 2011 / 11:49

    Great article, as soon as I started reading I realised that when I have a headache, the most effective thing for me is to suck on ice cubes. No medications just cold drinks and lots of ice, and I usually feel better.
    Thanks.

  2. Jeffrey Driban September 9, 2011 / 13:08

    Dustin: Great post. I suspect that you are very right about the fact that icing the neck is key in these cryo-interventions. It’s unlikely that icing the head will be capable of significantly decreasing the brain’s tissue temperature but by applying ice to the neck we might be able to decrease the temperature of the blood supply (that would actually be an interesting study). When applying ice to the neck it will be important to keep in mind that carotid sinus has baroreceptors so when you apply pressure to the region it will cause blood pressure to be elevated. For now clinicians are probably safe using most available cryotherapies but as new products enter the market it will be important for us to evaluate their efficacy on the field. Many people often forget that many of our modalities, including ice, are poorly understood. We know ice can reduce symptoms but it’s not clear if it really optimizes healing conditions or return to play outcomes. The application of cryotherapy for concussions is an exciting area and I look forward to seeing the results of their studies.

  3. loumemoli September 9, 2011 / 13:49

    Thank you for blogging on the IMMEDIATE use of mild hypothermia in treating post-traumatic brain injury. Most of the literature I’ve read is inconclusive with respect to hypothermia but that’s because most studies have applied cooling an hour or more after the injury. The cascade or sequence of deleterious events begins at the time of injury and continues with time. Immediate intervention (cooling) will stop or slow the process allowing time for transport to a medical facility where continued treatment of the injury can be accomplished.

    The current thinking among professional medical societies is based on studies that applied cooling long after the injury. How do we get medical societies to re-visit and re-evaluate this? You say that there are over a 1000 scientific articles that show benefit from hypothermia. How do we get the medical societies to look at this body of evidence? Their endorsement for immediate hypothermic intervention would influence the policies of professional, school, and recreational sports teams. It would go a long way to encouraging “ice ‘er down” as a common practice in any situation where a head injury (TBI) has incurred.

    Thermopraxis is obviously on the cutting edge of hypothermia research, so much so that they are trying to develop a technology that directly responds to this need. I visited their website and can see that there is a lot of science behind their claims… I hope that they are successful in generating discussion and that discussion will lead to the development of devices that can prevent or mitigate the long term effects of TBI. What we are doing now (nothing) isn’t working… nor is it addressing the immediate clinical need. Keeping players on the bench for a period of time after a concussion is great but it doesn’t do anything to stop the damage from the initial injury nor does it prevent long-term injury to players who will suffer head trauma in the future. If immediatly applied, controlled hypothermia seems to be the answer. How do we find a way to make this standard procedure! It should be a ‘no-brainer’ (pun intended).

  4. Jeffrey Driban September 10, 2011 / 14:47

    I thought everyone might enjoy this: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874892 It provides a brief description of the use of hypothermia for pediatric TBIs.

    As for the question: How do we get medical societies to re-visit and re-evaluate this [immediate application of cryotherapies]?

    A lot of this will have to be driven by the athletic training community (clinicians and researchers) since athletic trainers are the primary medical professional that is available to provide immediate acute care for most athletic injuries (at least within the United States). As clinicians, we need to buy in to immediate application of cryotherapy but doing that won’t get medical societies to revise or write new position statements. To develop new position statements more evidence will be required that shows not just the benefits of cryotherapy but that there is an additional benefit to immediate cryotherapy. We actually don’t have as much evidence on the benefits or cryotherapy as we might expect. For example:

    1. Pubmed search “therapeutic (hypothermia OR cryotherapy)” = 25,792 articles
    2. PubMed Search in step 1+ “acute” = 1,980
    3. PubMed search in step 1+ “(inflammat* OR healing)” = 1,108 articles
    4. PubMed search in step 3 + “acute” = 202 articles
    5. PubMed search at step 3 but limited to humans = 765
    6. PubMed search at step 3 but limited to clinical trials = 124
    7. Pubmed search at step 6 plus acute = 20 (most of which don’t apply to our goals)
    8. PubMed search step 1 + return to play = 5 articles (none of which actually evaluate the benefit of cryotherapy for improving RTP)
    9. PubMed search step 1 + “recovery time” = 32 articles (most of which don’t apply)

    Our therapeutic modalities, including cryotherapies, are capable of having considerable physiologic effects and yet they do not undergo the level of scrutiny that we would expect a pharmacological agent to undergo. Cryotherapy clearly reduces local metabolism, modulates pain, and influences the inflammatory process but we need more evidence that it is having the desired effect for different conditions (e.g., ankle sprains or TBI). Similar to early phase clinical trials we need to continue to figure out what the optimal dosing is (e.g., method of application, time of application). One of the most exciting aspects of the application of hypothermia for severe TBIs is that they are conducting randomized controlled trials comparing cryotherapy and standard of care. That’s the type of research that will some day lead to a position statement advocating these type of immediate interventions but we’ll need more research demonstrating that it is beneficial for mTBI when applied outside the hospital.

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