Bispectral index and lower margin amplitude of the amplitude-integrated electroencephalogram in neonates

Background: The lower margin amplitude (LMA) of the am- plitude-integrated electroencephalogram (aEEG) is sup- pressedinneonatesduringdeepsedation,afeaturethatis attributed to the bispectral index (BIS) in adults. Objective: We compare the BIS and the LMA of the aEEG in neonates. Methods: Thirty neurologically healthy neonates between 37 and 44 weeks postmenstrual age were included in this study. Twenty patients received sedoanalgesic therapy for various reasons. BIS and aEEG recordings were performed simultaneously. The digital data were imported in the nu- merical software environment Matlab®. The LMA of the aEEG was computed on a 1-min time scale and synchronized with the BIS data. The correlation between the time-depen- dent variables BIS and LMA was estimated using the Spear- man rank correlation index. Results: The median correlation between BIS and LMA was 0.3. Inclusion of recordings of high signal quality only into analysis improved the median corre-
lation index to 0.6. Conclusions: We found a light-to-moder- ate correlation between BIS and LMA in our study cohort and a good correlation in the subgroup with high signal quality.