Treating Hypoxic Ischemic Encephalopathy With Hypothermia

Abstract

Hypoxic-ischemic encephalopathy (HIE) is associated with high rates of morbidity and mortality, and only recently has an effective treatment been developed to mitigate its sequelae. Moderate therapeutic hypothermia (TH) (core temperatures of 33oC–35oC) has been found in a number of randomized clinical trials to reduce mortality and improve neurodevelopmental outcomes in full-term neonates with moderate or severe HIE. TH can be administered using various techniques, but optimal use dictates meticulous control of targeted core temperature (usually assessed as rectal temperature), and thus servo-controlled devices have an advantage. Treatment is applied for 72 hours, and then gradual rewarming is performed at a slow rate. Rapid rewarming and hyperthermia should be avoided because they may be associated with neuronal damage and reversal of the benefits of TH. Long-term outcomes, at ages 6 to 8 years, correlate well with the benefits observed at 18- to 24-month follow-up. Although better than any alternative therapy currently available, the rates of mortality and morbidity still remain high even when using TH.