Peri- and intraoperative EEG signatures in newborns and infants.

OBJECTIVE

The electroencephalographic derived indices have been developed for adult patients, however these monitors have not been validated for infants.

METHODS

Frontal EEGs were recorded in 115 infants aged <1 year [0-3-months (N = 27), 4-6-months (N = 30), 7-9-months (N = 29) and 10-12-months (N = 29)] who received general anaesthesia with sevoflurane. Total power (µV2) and relative β-, α-, θ-, δ-power (%) were analyzed. Additionally, in 20 EEGs event marker were added (baseline, loss of consciousness, intraoperative situation, extubation) to assess perioperative EEG dynamics.

RESULTS

Newborns show a mean relative δ-power at 80% in intraoperative EEG compared to infants (10-12 months) showing 47.5%. Relative β-power and α-power are low in newborns (mean 3.2% and 4.6%; respectively), with a marked increase in the older infants (4-6 months) (mean 10.9% and 14.4%; respectively). EEG dynamic in newborns from baseline (relative δ-power of 88%) to the intraoperative situation (80.5%) are discrete. In contrast infants >6-months have a strong reduction of relative δ-power from baseline to the intraoperative situation, which corresponds to an increase of faster frequencies.

CONCLUSIONS

Age dependent perioperative EEG signatures can be demonstrated in infants younger than one year.

SIGNIFICANCE: We demonstrate significant differences in EEG readouts between newborns and infants which questions our monitoring systems in paediatric anaesthesia.