Accuracy of Amplitude-integrated Electroencephalography in the Prediction of Neurodevelopmental Outcome in Asphyxiated Infants Receiving Hypothermia Treatment

Aim: Both hypothermia and central nervous system (CNS) drugs may alter the predictive accuracy of amplitude-integrated electroencephalography (aEEG) in hypoxic-ischaemic encephalopathy (HIE). The aim was to assess the predictive value of aEEG in hypothermia-treated HIE infants. Furthermore, we intended to investigate the association of cumulative doses of CNS drugs with aEEG recovery.

Methods: Seventy term HIE infants treated with hypothermia for 72 h were continuously monitored by single-channel aEEG. Doses of administered morphine, phenobarbitone and midazolam were recorded. Poor outcome was defined as death or severe neurodevelopmental delay at 18-24 months (Bayley Scales of Infant Development II), good outcome as absence of these criteria.

Results: Poor outcome n = 26, good outcome n = 44. Positive predictive values (PPV) of an abnormal background pattern to predict poor outcome were 0.5 at 6 h; 0.65 at 24 h; 0.82 at 48 h and 0.92 at 60 h. All infants who developed sleep-wake cycling (SWC) had a favourable outcome; the nondevelopment of SWC resulted in a PPV of 0.73 for a poor outcome. Cumulative doses of the investigated drugs did not differ between infants having an onset of a recovered background pattern before or after 24 h.

Conclusion: Amplitude-integrated electroencephalography provides reliable prediction of outcome from the 48th hour during hypothermia in HIE infants. Commonly used CNS drugs in HIE infants do not significantly delay aEEG recovery.