The efficacy of hypothermia in hypoxic-ischemic encephalopathy at 18 mo or more.

OBJECTIVE: To evaluate the efficacy of hypothermia in the treatment of hypoxic-ischemic encephalopathy (HIE) in neonates at 18 mo of age or more. Also to examine whether the severity of encephalopathy affects the efficacy of hypothermia on mortality and neurodevelopmental disability.

METHODS: The authors recruited the trials that assessed the efficacy of therapeutic hypothermia in the treatment of HIE in neonates at 18 mo of age or older up to April 2011. The meta- analysis was performed using a fixed effect model.

RESULTS: Hypothermia significantly reduced the combined rate of death or neurodevelopmental disability (RR = 0.74, 95% CI: 0.67 to 0.82; RD = -0.13, 95% CI: -0.18 to -0.08; NNT = 7, 95% CI: 6 to 9) among infants at 18 mo of age or older. Hypothermia reduced the rate of death (RR = 0.75, 95% CI: 0.64 to 0.88), neurodevelopmental disability (RR = 0.65, 95% CI: 0.54 to 0.79), cerebral palsy (RR = 0.65, 95% CI: 0.53 to 0.80), developmental delay (RR = 0.72, 95% CI: 0.57 to 0.92), neuromotor delay (RR = 0.78, 95% CI: 0.61 to 0.99) and visual deficit (RR = 0.59, 95% CI: 0.36 to 0.99). Analysis of the severity of disease showed that hypothermia reduced the combined rate of death or neurodevelopmental disability not only in moderate encephalopathy infants (RR = 0.63, 95% CI: 0.53 to 0.76) but also in severe encephalopathy infants (RR = 0.82, 95% CI: 0.74 to 0.92).

CONCLUSIONS: Hypothermia has a beneficial effect in the treatment of HIE in neonates at 18 mo of age or older.