Processed electroencephalogram in children anesthetized with sevoflurane. Is it feasible?

Abstract

BACKGROUND AND OBJECTIVES: EEG-derived bispectral index (BIS), has been indicated as a major substrate for measuring hypnotic effects of anesthetic drugs. However, there are only limited data on the use of EEG in anesthetized children. This study aimed at evaluating changes in BIS, SEF95%, relative delta band frequency amplitude (δ%) and suppression rate (SR) in children, correlating these changes with sevoflurane pharmacodynamic variables (EC and EC/MAC) as compared to adults. METHODS: Participated in this study 100 patients of both genders, aged 0 to 40 years, physical status ASA I and II. All patients were induced with sevoflurane followed by neuromuscular blocker at BIS 30. Patients were distributed in 5 groups: GI (20) - 0 to 6 months; GII (20) > 6 months to 2 years; GIII (20) > 2 to 12 years; GIV (20) > 12 to 18 years and GV (20) > 18 to 40 years. Five moments were evaluated for each group: M1 (awaken); M2 (BIS 60); M3 (BIS 50); M4 (BIS 40) and M5 (emergence). The following parameters were recorded for all moments: SBP, DBP, HR, BIS, SEF95%, δ%, suppression rate, EC and EC/MAC. RESULTS: Both BIS and SEF95% values for all age groups directly correlated to sevoflurane's EC/MAC at BIS values of 40, 50, 60 and at emergence, considering MAC values for age (p > 0. 05). δ% values in GI were higher than in any other group during all five moments (p < 0. 05). CONCLUSIONS: Unlike δ%, the variations of which seem brain maturation-related, BIS and SEF95% may be used to monitor sevoflurane's anesthetic depth in children aged 0 to 12 years, observing the parameters suggested for adults.