Does Hypothermia Lead to Better Outcomes in Newborns with Asphyxial Encephalopathy?

Hypothermic therapy has recently been shown to reduce morbidity and mortality associated with perinatal asphyxia. One randomized clinical trial showed significantly lower mortality and less severe disability when hypothermia was employed (JW Pediatr Adolesc Med Dec 30 2005). In the current multicenter, randomized trial, investigators in the U.K. evaluated the effect of total-body cooling on survival and neurodevelopmental outcomes at age 18 months in 325 asphyxiated infants (gestational age, ≥36 weeks). Infants were randomized to receive intensive care with or without hypothermia (body temperature of 35.5°C for 72 hours) before 6 hours of age.

At 18 months, 42 infants had died, and 32 survived with severe disability in the hypothermia group; in the control group, 44 infants had died, and 42 survived with severe disability. The difference in the combined rate of death or disability at 18 months (the primary outcome) was not statistically significant. However, survival without neurological abnormality at 18 months was significantly higher in the hypothermia group (44% vs. 28%; relative risk, 1.57). Hypothermia was associated with significantly better outcomes among survivors for 5 of 12 neurological measures, including lower risk for cerebral palsy (RR, 0.67) and better mental and psychomotor developmental scores. The authors concluded that hypothermia did not lower mortality associated with perinatal asphyxia but did improve neurological outcomes in survivors.