Effects of lidocaine bolus and infusion on neuromonitoring by bispectral index (BIS®), electroencephalogram periodic and aperiodic activity, and Surgical Pleth Index® during propofol-remifentanil anaesthesia: a single-centre prospective observational study

The authors aimed to evaluate the dose-dependent effects of lidocaine on EEG spectral features and processed parameters like bispectral index (BIS) and spectral edge frequency (SEF) during propofol-remifentanil anesthesia. They found that lidocaine administration led to early changes in EEG activity, specifically an increase in delta-band and a decrease in beta-band activity, before any significant alterations in BIS, SEF, or Surgical Pleth Index (SPI) were observed. These findings suggest that lidocaine's antinociceptive effects may contribute to its anesthetic-sparing properties, although the interpretation of these EEG changes requires further investigation.