Resuscitation on ice: Implementing therapeutic hypothermia in a district general hospital

Nick Plummer, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0SP

In 2003, the Intenational Liaison Committee on Resuscitation (ILCOR) recommended that all unconscious adult patients who achieved return of spontaneous circulation (ROSC) after an out-of-hospital arrest (OHCA) be cooled to 32–34C for 12-24 hours (1), reducing cerebral oxygen consumption and suppressing the damaging “reperfusion injury” (2).

Since then, the use of so-called therapeutic hypothermia (TH) has become common practice for the management of OHCA, with observational trials suggesting that the faster the target temperature range is reached, the more favourable the neurological outcomes, with the Royal College of Anaesthetists (RCA) suggesting 240 minutes from ROSC as an audit standard (3).

Patil et al. examined retrospectively the implementation of TH in patients presenting to a DGH ED following OHCA between January 2002 and December 2008 (4). During this period, 83 patients were admitted to intensive care (ICU), of which 67 (81%) were actively cooled according to ILCOR recommendations, with the 16 who were not cooled having recognized exclusion criteria. The median time from ROSC to initiation of cooling was 60 (40-165) minutes and time to reach 34C 175 (40-420) minutes.

In more detail, of the 44 (67%) achieving 34C within the RCA standard of 4 hours, 23 (55%) survived with good neurological outcomes. Of the 23 that were cooled at least 240 minutes after ROSC, only 9 (39%) survived with good neurological outcomes, though this is an improvement on the 16 that were not cooled, where 13 (81%) died and 3 (19%) survived with a good neurological outcome.

More interestingly, Patil et al. studied the changes with time in how and when this cooling was initiated. They noted that the average time to achieve target temperature from ROSC dropped from over 400 minutes in 2002 to under 50 in 2008, which corresponded from a change from cooling being predominantly ICU lead to being almost entirely initiated in the ED, highlighting that in 29 patients the temperature actually increased on leaving the ED for ICU – 13 (44%) of these patients survived with a good neurological recovery.

They conclude that TH to ILCOR and RCA guidelines is perfectly achievable in a DGH ED setting, and at minimal cost, and is associated with vastly improved outcomes following OHCA. They also note the strong correlation between the time taken to cool the patient and neurological outcome, suggesting that ultimately the most effective way of shortening the time to target temperature is to start cooling pre-hospital as soon as ROSC is achieved, or perhaps even during CPR of patients in ventricular fibrillation.

References: 

1. Writing Group, Nolan JP, Morley PT, Vanden Hoek TL, Hickey RW, Members of the Advanced Life Support Task Force, Kloeck WGJ, Billi J, Böttiger BW, Morley PT, Nolan JP, Okada K, Reyes C, Shuster M, Steen PA, Weil MH, Wenzel V, Member of the Pediatric Life Support Task Force, Hickey RW, Additional Contributors, Carli P, Vanden Hoek TL, Atkins D. Therapeutic Hypothermia After Cardiac Arrest. Circulation 2003 Jul;108(1):118 -121.
doi: 10.1161/01.CIR.0000079019.02601.90

2. Polderman KH, Herold I. Therapeutic hypothermia and controlled normothermia in the intensive care unit: practical considerations, side effects, and cooling methods. Crit. Care Med. 2009 Mar;37(3):1101-1120.
doi: 10.1097/CCM.0b013e3181962ad5

3. Nolan J. Implementation of therapeutic hypothermia. The Royal College of Anaesthetists. Raising the Standard: a compendium of audit recipes; Section 7.8: 148. Available from: http://www.rcoa.ac.uk

4. Patil S, Bhayani S, Denton JM, Nolan J. Therapeutic hypothermia for out-of-hospital cardiac arrest: implementation in a district general hospital emergency department [Internet]. Emergency Medicine Journal 2010 Dec; Available from: http://emj.bmj.com/content/early/2010/12/22/emj.2010.091439.abstract
doi: 10.1136/emj.2010.091439

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