In three randomised controlled trials encompassing 767 infants with hypoxic-ischaemic encephalopathy, induced moderate hypothermia for 72 hours significantly reduced the combined rate of death and severe disability, with a number needed to treat of nine (95% CI 5 to 25). Hypothermia increased survival with normal neurological function, with a number needed to treat of eight (95% CI 5 to 17), and in survivors reduced the rates of severe disability and cerebral palsy. The studies used different cooling methods and different target temperatures (33-34 deg C vs 34-35 deg C), suggesting the method of cooling itself is not important as long as therapeutic hypothermia is achieved.
Neurological outcomes at 18 months of age after moderate hypothermia for perinatal hypoxic ischaemic encephalopathy: synthesis and meta-analysis of trial data
BMJ. 2010 Feb 9;340:c363