In 2003 the International Liaison Committee on Resuscitation (ILCOR) published guidelines recommending all patients admitted comatose to hospital following an out-of-hospital cardiac arrest (OHCA) with an initial rhythm of ventricular fibrillation should be treated with therapeutic hypothermia for a period of 12 to 24 hours . We aimed to determine how many units are using hypothermia as part of their post-cardiac arrest management and when each of the ICUs implemented the therapy. Other objectives were to determine what cooling techniques are being used, the target temperature and the duration of cooling used.
The 248 UK ICUs listed in the Directory of Critical Care Services were contacted by telephone by one of the authors. The duty ICU consultant or nurse in charge was asked a standardised set of questions.
We obtained responses from 244 of 248 (98.3%) of ICUs. Currently, 209 (85.6%) ICUs are using hypothermia as part of post-cardiac arrest management. Since 2003, there has been an increase annually in the number of units using hypothermia, with the majority of units starting in 2007 or 2008 (Figure 1). Of the units who use hypothermia as part of their post-cardiac arrest management, 99% are using it to treat patients after OHCA from shockable rhythms, 60.6% are using it to treat patients after OHCA from nonshockable rhythms, and 63.5% are using it after in-hospital cardiac arrest. Cooling is initiated with intravenous cold fluid in 71%. The commonest technique to maintain hypothermia is to use ice; used by 55% of units. Most ICUs (89.9%) aim for a temperature of 32 to 34°C and the duration of hypothermia is 24 hours in 141 ICUs (67.5%).
Figure 1. Implementation of therapeutic hypothermia in UK ICUs by year.
Generalised implementation of this clinical guideline in the UK has taken about 5 years but now the majority of ICUs are using therapeutic hypothermia as part of post-cardiac arrest management.