Prediction of EEG-Derived Wavelet Index for End-Tidal Sevoflurane in Pediatric Anesthesia: A Prospective,...

Processed electroencephalogram is able to assess the depth of anesthesia. EEG-derived wavelet index (WLi) is a novel indicator derived from EEG on the basis of wavelet analysis.

We primarily tested whether WLi can reflect changes in end-tidal sevoflurane (sevo_ET) in pediatric patients, especially during the transition from awake status to 0.6 MAC. We then explored the concentration-effect relationship between sevo_ET and WLi and tested the effect of age on WLi.

This prospective, single-blind study was performed at a tertiary care hospital affiliated with Shanghai Jiao Tong University School of Medicine, China. WLi and BIS were measured in 40 pediatric patients aged 6 months to 6 years who underwent elective surgeries after sevo_ET was maintained at 2.0, 1.3, and 0.6 age-adjusted MAC in stepwise decrements.

WLi and BIS had comparable performance in predicting the transition of anesthesia status from awake to sevo_ET at 0.6 MAC and from 1.3 to 2.0 MAC. In contrast to BIS, WLi exhibited a plateau effect and failed to predict the transition from 0.6 to 1.3 MAC. The indicator-specific performance of prediction was supported by their concentration-effect relationships, with EC₅₀ of 0.38 MAC for WLi and 0.95 MAC for BIS. Further, we found that the WLi values between individuals were independent of age.

WLi can reflect the transition of anesthesia status from light to moderate sedation, and the plateau effect might indicate adequate depth of anesthesia during deeper sedation and general anesthesia.