🤖Current electroencephalogram (EEG)-derived measures like BIS, provide information on cortical activity and hypnosis but are less accurate regarding subcortical activity, which is expected to vary with the degree of antinociception.
🤖Efforts to develop methods for monitoring these subcortical activities produced a few indices, which may provide some use intra-operatively
🤖Recently, the neurophysiologically based EEG measures of cortical input (CI) and cortical state (CS) have been shown to be prospective indicators of analgesia/anti-nociception and hypnosis, respectively. Composite Cortical State (CCS) is an alternate measure of CS.
🤖Composite Variability Index (CVI) is another recently developed EEG-derived measure of antinociception based on a weighted combination of BIS and estimated electromyographic activity.
🤖CCS and BIS show strong correlations, suggesting that they behave similarly as indicators of hypnosis.
Reference: Comparisons of Electroencephalographically Derived Measures of Hypnosis and Antinociception in Response to Standardized Stimuli During Target-Controlled
Propofol-Remifentanil Anesthesia, Mehrnaz Shoushtarian, Marko M. Sahinovic, Anthony R. Absalom, Alain F. Kalmar, Hugo E. M. Vereecke, David T. J. Liley and Michel M. R. F. Struys, anesthesia-analgesia, February 2016 • Volume 122 • Number 2