AEP-monitor/2 derived, composite auditory evoked potential index (AAI-1.6) and bispectral index as predictors of sevoflurane concentration in children.
BACKGROUND
Level of anesthesia may be predicted with the auditory evoked potential or with passive processed electroencephalogram (EEG) parameters. Some previous reports suggest the passive EEG does not reliably predict level of anesthesia in infants. The AAI-1.6 is a relatively new index derived from the AEP/2 monitor. It combines auditory evoked potentials and passive EEG parameters into a single index. This study aimed to assess the AAI-1.6 as a predictor of level of anesthesia in infants and children.


METHODS
Four infants aged less than 1 year, and five older children aged between 2 and 11 years were enrolled. They all had uniform sevoflurane anesthesia for cardiac catheterization. The AAI-1.6 and bispectral index (BIS) were recorded after achieving equilibrium at 1.5%, 2% and 2.5% sevoflurane, and immediately prior to awakening. The prediction coefficient (Pk) for BIS and AAI-1.6 was calculated and compared within each age group.


RESULTS
The Pk for the AAI-1.6 was low in both 0-1 and 2-11 years age groups. In the 2-12 years group, the Pk for BIS was significantly higher than the Pk for the AAI-1.6 (Pk for BIS: 0.89, Pk for AAI-1.6: 0.53, P < 0.01). In contrast in the 0-1 year age group there was no evidence for a difference between the Pk for BIS and the Pk for the AAI-1.6 (Pk for BIS: 0.74, Pk for AAI-1.6: 0.53, P = 0.25).


CONCLUSIONS
This preliminary study suggests AAI-1.6 is a poor predictor of sevoflurane concentration in infants and children.
Ironfield
Craig M
CM
Department of Anaesthesia & Pain Management, Royal Children's Hospital, Melbourne, Australia.
Davidson
Andrew J
AJ
D000367:Age Factors; D000758:Anesthesia / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D006328:Cardiac Catheterization / Q000379:methods; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D008991:Monitoring, Physiologic / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D000077149:Sevoflurane; D013997:Time Factors
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane