There has been an explosion of conversation about Targeted Temperature Management (TTM) in post-arrest patients following the publication of the TTM trial by Nielson et al in the NEJM recently.
Full article - Engl J Med 2013; 369:2197-2206 December 5, 2013
There has been loads of commentary and debate and I won't try to re-invent the wheel here.
Obviously I suggest you read the paper, listen to the podcasts and decide on your own opinion. However, I would probably summarise what I learnt as:
- HypERthermia after a cardiac arrest is probably bad (not contained in this paper but useful background knowledge)
- Controlling the temperature to 36°C may be the same as cooling the patient to 33°C, but we don't know that. We do know that there isn't a large difference.
- Studies to prove similarity between two interventions have to be massive (studies to show no difference can be smaller - MATHS fans)
- Cooling is an intervention and like any other thing we give (e.g. drugs) there is probably a dose-response relationship
- Neuroprognostication is difficult in the context of hypothermia and difficult post-cardiac arrest, and the two combined make things exceptionally tricky.
It may well be that different patients need different temperatures (for example patients with a long down-time and asystole might require longer at a lower temperature) - but clearly more studies are needed before this becomes practice.
There's some useful background info on post-arrest hypothermia from Lewis Macken from SMACC 2013. This talk pre-dates the release of this trial but has some really interesting points, esp how small the numbers are in existing RCTs
A very readable summary from The Intensive Care Network
Interview with Nielson, the primary author of the study
St. Emlyn's info on the stats behind the trial