While I do not have any research work to prove it does, I have seen that it indeed help two of our patients who went to cardiac arrest after surgery. It could have been other factors modifying the effect but the patients did survive after almost a month of ICU stay and 2 months of hospital stay.

So if you ask me, I would say most likely it does.

I don' have the evidence about it but, I think that control for Target point "36 degree temporature" is also one of hypothermia therapy or mutant therapy.

According to the ACCF/AHA Guidelines, “Therapeutic hypothermia after cardiac arrest should be started as soon as possible in comatose patients with STEMI and out-hospital cardiac arrest”, “cooling should begin before or at time of cardiac catherization”( Circulation 2013;127:e 362) (level of evidence:B).

Whereas, according to the two pivotal series published in the N England, as others, our targeted temperature was between 32-34 Celsius for 24 hours. The recent controlled trial (939 CA included), without biases in the randomization raises questions (N Engl J Med, Nov 17, 2013). Since endovascular cooling catheter are expansive, since 33 Celsius targeted extracorporeal cooling is time consuming and not always easy to reach with ice packs (nurse time ++) and/or surface temperature devices, it believe that a 36 targeted temperature should be the best guidelines.

Thus, as hypothermia permits a 50% survival at days 180, it is now impossible to compare hypothermia during 24 h as soon as possible after cardiac arrest with its “natural history” and its frequent hyperthermia.

To conclude, I think that hypothermia is useful and must initiated as soon as possible, that each team will have to redefine their target;

I think this research is important to read

On the basis of the published evidence to date, the Advanced Life Support (ALS) Task Force of the International Liaison Committee on Resuscitation (ILCOR) made the following recommendations in October 2002:

Unconscious adult patients with spontaneous circulation after out-of-hospital cardiac arrest should be cooled to 32°C to 34°C for 12 to 24 hours when the initial rhythm was ventricular fibrillation (VF).

Such cooling may also be beneficial for other rhythms or in-hospital cardiac arrest

source

(http://circ.ahajournals.org/content/108/1/118.full)

Whereas in 2002 the targeted temperature was between 32 to 34 celsius for 12 to 24 hours for out-of -hospital cardiac arrest, according to the recent CRT published in the New England (nov 2013), patients survival was similar when the targeted temperature was only 36 celsius. Therefore, we can not claim anymore that patients with spontaneous circulation after cardiac arrest should be cooled to 32 to 34 celsius.

I agree with the fact that in-hospital cardiac arrest should be cooled as out-of hospital patients, and many of those who was transferred to our ICU were cooled, despite the absence of validation in this setting.

For children, the ongoing THAPCA trial will help to answer this question. There is currently scientific equipoise on this matter. Individual practices vary.

Luis,

I think there's good evidence that it's effective in reducing systemic tissue damage from ischemia, hypoxia, and hyperglycemia that result from lack of circulatory dynamics. Much of the preventative effects occur at the mitochondria, organelles whose actions are integral to several disease states. Specifically, hypoxic mitochondria will produce a significantly greater amount of reactive oxygen species during anoxia. Several mitochondrial membrane processes have been shown to be temperature-dependent.

http://www.utoledo.edu/med/depts/bioinfo/pdf/facpdfs/beavis5.pdf

http://link.springer.com/article/10.1007%2FBF00293466

Several hospitals are using induced hypothermia for therapy. Here's a visual:

https://maps.google.com/maps/ms?hl=en&gl=us&ptab=2&ie=UTF8&oe=UTF8&msa=0&msid=212048642284666917326.0004bb47ea85abf426db5&mid=1332340283&dg=feature

Induced hypothermia appears to be consistently effective in VF/VT cardiac arrest, but the results are inconclusive for non-VF/VT cardiac arrest. Perhaps the timeline of pathology progression is different in the two types of arrest. Either way, more research can be done for non-VF/VT arrest.

http://ccforum.com/content/pdf/cc12524.pdf

I found a fairly comprehensive report from the National Institute for Health and Care Excellence:

http://www.nice.org.uk/nicemedia/live/12990/51339/51339.pdf

Hope this helps.

Alex

Dear Friends

For protection of the brain and other organs, hypothermia is a helpful therapeutic approach in patients who remain comatose (usually defined as a lack of meaningful response to verbal commands) after ROSC. Questions remain about specific indications and populations, timing and duration of therapy, and methods for induction, maintenance, and subsequent reversal of hypothermia. One good randomized trial* and a pseudorandomized trial** reported improved neurologically

intact survival to hospital discharge when comatose patients with out-of-hospital ventricular fibrillation (VF) cardiac arrest were cooled to 32°C to 34°C for 12 or 24 hours beginning minutes to hours after ROSC. Additional studies with historical control groups show improved neurological outcome after therapeutic hypothermia for comatose survivors of VF cardiac arrest.

*HACA. Hypothermia After Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med. 2002;346:549 –556.

**Bernard SA, Gray TW, Buist MD, Jones BM, Silvester W, Gutteridge G,

Smith K. Treatment of comatose survivors of out-of-hospital cardiac

arrest with induced hypothermia. N Engl J Med. 2002;346:557–563.

Hypothermia improves at evidence the neuologic outcome of VF/VT outside hospital cardiac arrest, but the tarteged temperature was recently a matter of debate. 36 celsius should be prefered to 32-34, since less nurse time consuming.

Normothermia 36ºC should be the end point after cardiac arrest based on the most precise RCT performed till nowadays (TTM trial).

N Engl J Med 2013;369:2197-206.

The question could be...should we cool all our patients after cardiac arrest or only those whom present temperature above 37ºC...?