Whole Body Hypothermia for Neonatal Hypoxic Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) may cause neurodevelopmental deficits and death in infants. The rate of HIE in the U.S. (2 per 1000 live births) has not changed in the past 20 years. Researchers assessed whole-body cooling in a multisite, randomized trial that involved 208 newborns (gestational age, ≥36 weeks) with HIE (defined as either severe acidosis or perinatal complications and resuscitation at birth). Within 6 hours of birth, infants received either usual care (overhead radiant warmers) or whole-body cooling (with water blankets regulated to achieve an esophageal temperature of 33.5oC) for 72 hours.

Compared with infants who received usual care, those who underwent cooling were significantly less likely to have died or have moderate or severe disability (collective rates of IQ, motor function, blindness, and hearing impairment) at age 18 to 22 months (44% vs. 62%). Adjustment for severity of encephalopathy at randomization did not change the results. Individual rates of cerebral palsy, blindness, and hearing impairment among survivors did not differ significantly between the two groups. The incidence of serious adverse events (e.g., hypotension, cardiac arrhythmia, or oliguria) was similar in the two groups.

Comment: These encouraging results suggest that whole-body cooling may be an effective therapy for hypoxic-ischemic encephalopathy in term and asphyxiated infants. In a previous randomized study of brain cooling for HIE, no differences in rates of death and disability were found. As noted by an editorialist, one explanation for the different results is that systemic whole-body hypothermia resulted in more rapid cooling than brain cooling alone. Unfortunately, many neonates with HIE are born in community hospitals, where quickly instituting such an intensive intervention as whole-body cooling may be difficult to accomplish. In addition, these results do not pertain to premature infants.

Howard Bauchner, MD

Published in Journal Watch Pediatrics and Adolescent Medicine December 30, 2005

Source

Shankaran S et al. Whole-body hypothermia for neonates with hypoxic-ischemic encephalopathy. N Engl J Med 2005 Oct 13; 353:1574-84.

Papile L-A. Systemic hypothermia -- A "cool" therapy for neonatal hypoxic-ischemic encephalopathy. N Engl J Med 2005 Oct 13; 353:1619-20.