Therapeutic Hypothermia After Cardiac Arrest
An Advisory Statement by the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation
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.
Induction of moderate hypothermia (28°C to 32°C) before cardiac arrest has been used successfully since the 1950s to protect the brain against the global ischemia that occurs during some open-heart surgeries. Successful use of therapeutic hypothermia after cardiac arrest in humans was also described in the late 1950s1–3 but was subsequently abandoned because of uncertain benefit and difficulties with its use.4 Since then, induction of hypothermia after return of spontaneous circulation (ROSC) has been associated with improved functional recovery and reduced cerebral histological deficits in various animal models of cardiac arrest.5–8 Additional promising preliminary human studies have been completed.9–16 At the time of publication of the Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, the evidence was insufficient to recommend use of therapeutic hypothermia after resuscitation from cardiac arrest.17
In 2002 the results of 2 prospective randomized trials were published that compared mild hypothermia with normothermia in comatose survivors of out-of-hospital cardiac arrest.18,19 One study was undertaken in 9 centers in 5 European countries19; the other was conducted in 4 hospitals in Melbourne, Australia.18
The criteria for entry into these trials were similar: ROSC, patients remaining intubated and ventilated, with persistent coma after out-of-hospital cardiac arrest due to VF. In the European study, the median Glasgow Coma Scale score on hospital admission in both groups …