Objective: To determine the effectiveness and safety of moderate whole-body hypothermia in newborns with hypoxic-ischemic encephalopathy born in hospitals with and without newborn intensive care facilities or complicated hypothermia equipment.
Design: Multicenter, international, randomized controlled trial.
Setting: Neonatal intensive care units in Australia, New Zealand, Canada, and the United States (N = 28) from February 2001 through July 2007.
Participants: Newborns of 35 weeks' gestation or more, with indicators of peripartum hypoxia-ischemia and moderate to severe clinical encephalopathy, randomly allocated to hypothermia (n = 110) or standard care (n = 111).
Intervention: Whole-body hypothermia to 33.5°C for 72 hours or standard care (37°C). Infants who received hypothermia were treated at ambient environmental temperature by turning off the radiant warmer and then applying refrigerated gel packs to maintain rectal temperature at 33°C to 34°C.
Main outcome measures: Death or major sensorineural disability at 2 years of age.
Results: Therapeutic hypothermia reduced the risk of death or major sensorineural disability at 2 years of age: 55 of 107 infants (51.4%) in the hypothermia group and 67 of 101 infants (66.3%) in the control group died or had a major sensorineural disability at 2 years (risk ratio, 0.77 [95% confidence interval, 0.62-0.98]; P = .03). The mortality rate decreased, and the survival rate free of any sensorineural disability increased. Adverse effects of hypothermia were minimal.
Conclusions: Whole-body hypothermia is effective and appears to be safe when commenced within 6 hours of birth at the hospital of birth in term and near-term newborns with hypoxic-ischemic encephalopathy. This simple method of hypothermia could be used within strict protocols with appropriate training on correct diagnosis and application of hypothermia in nontertiary neonatal settings while awaiting retrieval and transport to the regional neonatal intensive care unit.
Trial registration: anzctr.org.au Identifier: ACTRN12606000036516.