Amplitude-Integrated EEG and Cerebral Near-Infrared Spectroscopy in Cooled, Asphyxiated Infants

To assess the predictive value of amplitude-integrated electroencephalography EEG (aEEG) and near-infrared spectroscopy (NIRS) during therapeutic hypothermia.

We studied 39 cooled, asphyxiated infants. We assessed aEEG and calculated mean regional cerebral oxygen saturation (rcSO₂) during and after treatment. At 30 months, we performed a neurological examination and administered the Bayley Scales of Infant and Toddler Development, 3rd edition. We calculated the odds ratios (ORs) of abnormal aEEG and rcSO₂ for severely abnormal outcome.

At 6 and 12 hours, severely abnormal aEEGs predicted severely abnormal outcomes (OR, 7.7 [95% confidence interval, CI, 1.39-42.6] and 24.4 [95% CI 4.2-143] respectively), as did epileptic activity (OR 28.9, 4.6-183). During the first 48 hours, rcSO₂ was not associated with outcome, but at 72 hours after birth and after rewarming it was, with ORs for severely abnormal outcomes of 12.8 (1.31-124) and 21.6 (1.05-189), respectively. In multivariate analyses, aEEG and rcSO₂ remained independently predictive in the model at 48 hours and significantly from 72 hours after birth onward.

aEEG was a strong predictor of adverse outcome. After 48 hours of cooling, a higher rcSO₂ was associated with a severely abnormal outcome, adding to the predictive value of aEEG in cooled, asphyxiated infants.