Nociception Effect on Frontal Electroencephalogram Waveform and Phase-Amplitude Coupling in Laparoscopic Surgery

Area of Science:

• Anesthesiology
• Neuroscience
• Signal Processing

Background:

• Electroencephalogram (EEG) patterns during anesthesia reflect the nociception-analgesia balance.
• While alpha dropout and delta/beta arousal are known responses to noxious stimuli, other EEG signatures are less understood.
• Investigating diverse EEG signatures can reveal new nociception markers and deepen our understanding of pain neurophysiology.

Purpose of the Study:

• To analyze changes in electroencephalogram (EEG) frequency patterns and phase-amplitude coupling during laparoscopic surgeries.
• To identify novel EEG markers associated with nociception and the analgesia balance under anesthesia.

Main Methods:

• Evaluated 34 patients undergoing laparoscopic surgery.
• Analyzed EEG frequency band power and phase-amplitude coupling across incision, insufflation, and opioid stages.
• Utilized repeated-measures ANOVA with a mixed model and Bonferroni correction for statistical analysis.

Main Results:

• Observed significant decreases in alpha power percentage post-incision and during insufflation, with recovery after opioid administration.
• Found a decrease in the delta-alpha phase-amplitude coupling's modulation index (MI) after incision and during insufflation, which also recovered post-opioid.
• These changes highlight specific EEG signature alterations in response to noxious stimuli during surgery.

Conclusions:

• Alpha dropout during noxious stimulation is confirmed in laparoscopic surgery under sevoflurane anesthesia.
• Decreased delta-alpha phase-amplitude coupling (MI) during noxious stimuli suggests its potential as a novel indicator.
• Phase-amplitude coupling analysis of EEG offers a promising new method for assessing the nociception-analgesia balance in anesthesia.