[Neuroprotection with hypothermia for hypoxic ischemic encephalopathy in term newborn: review of the learning].

The hypothermia treatment for neonatal hypoxic ischemic encephalopathy is a concept revisited for more than 10 years. With this strategy, animal studies have shown an 80% reduction of brain damage. Conditions for the practice of hypothermia, to obtain neuroprotection, have been described in these studies: rapidity of the onset of cooling after the hypoxic ischemic event, prolonged duration during several hours, ability to obtain neuroprotection with two methods of cooling, selective head cooling or whole body hypothermia. Pilot studies in human newborns have demonstrated the feasibility of these strategies without immediate adverse effects. Two large randomised trials have been conducted in 2005 to test the efficacy. Only with the strategy of whole body cooling, the incidence of poor outcome at 18 months (death or severe disability) was statistically decreased (44% versus 66% in the control group). This reduction seems especially significant in the sub group of intermediate severity (48% versus 66%), whereas severe forms (Grade III in the Sarnat and Sarnat classification) were probably not ameliorated with this treatment. Now, the major problem is to determine the best indications for hypothermia with an early and precise assessment of the grade of the encephalopathy.