Treatment with mild whole body hypothermia after birth asphyxia was evaluated in 10 of 16 newborns with EEG burst suppression evidence of a bad prognosis, followed at the Imperial College School of Medicine, London, UK. All infants selected for treatment had convulsions and a severe encephalopathy. Hypothermia was instituted within 6 hours of birth and continued for 48 hours. Changes included prolonged metabolic acidosis, decreased blood potassium, lower heart rate, and higher mean blood pressure, but were not associated with clinical complication. Unusual MRI findings in 3 infants were sinus thromboses and cerebral infarction. Six infants had normal follow-up neurologic exams or only minor abnormalities. Three infants died and 1 had major abnormalities. EEG activity returned to a more continuous pattern by 13 hours in 5 infants, although seizures recurred. EEG suppression was greater in infants with a poor outcome than in the 6 who recovered. Of 6 untreated infants with a normal initial EEG, none developed severe encephalopathy or neurologic sequelae. 
COMMENT. Prolonged mild hypothermia has been evaluated in the treatment of asphyxiated neonates at high risk of developing severe neonatal encephalopathy. A burst suppression pattern in the EEG is indicative of increased risk of severe encephalopathy and possible trial of hypothermia.