- Jerry P Nolan, consultant in anaesthesia and intensive care medicine1,
- Jasmeet Soar, consultant in anaesthesia and intensive care medicine2
- 1Royal United Hospital NHS Trust, Bath BA2 7AJ, UK
- 2Southmead Hospital, North Bristol NHS Trust, Bristol, UK
- Correspondence to: J P Nolan
The use of mild hypothermia in comatose survivors of cardiac arrest has been shown to improve neurological outcome in both animals and humans.1 2 The evidence of benefit is strongest for people who have had a ventricular fibrillation cardiac arrest outside hospital, but data are beginning to emerge supporting its use in other types of arrest.
A randomised trial3 and a pseudorandomised (by day of the month) trial4 of cooling unconscious patients to 32-34ºC after ventricular fibrillation cardiac arrest outside hospital both recorded benefits.3 4 The randomised Hypothermia After Cardiac Arrest (HACA) study enrolled 275 patients (8% of those assessed).3 Those in the hypothermia group were sedated, paralysed, ventilated, and surface cooled to 32-34°C for 24 hours. Seventy five (55%) of the 136 in the hypothermia group showed a favourable neurological outcome at 6 months compared with 54 (39%) of 137 in the normothermia …