Decrease of the peak heights of EEG bicoherence indicated insufficiency of analgesia during surgery under general...

Area of Science:

• Anesthesiology
• Neuroscience
• Signal Processing

Background:

• Electroencephalographic bicoherence (pBIC) peaks, specifically pBIC-high and pBIC-low, are known to decrease after surgical incision.
• Fentanyl administration has been shown to restore these pBIC peaks.
• This study investigates the utility of pBICs as indicators for adequate intraoperative analgesia.

Purpose of the Study:

• To evaluate the effectiveness of electroencephalographic bicoherence peaks (pBICs) in assessing intraoperative analgesia.
• To compare the sensitivity of pBICs against standard anesthesia monitoring for detecting inadequate analgesia.

Main Methods:

• Fifty patients (27-65 years, ASA-PS I or II) undergoing elective surgery were enrolled.
• Bispectral Index (BIS) monitor and Bispectrum Analyzer software were used to assess pBICs.
• Additional fentanyl was administered when pBIC-high or pBIC-low decreased by 10% or fell below 20%.

Main Results:

• Specific decreases in pBIC-high and pBIC-low were observed following incision, triggering additional fentanyl administration.
• The mean values for pBIC-high and pBIC-low showed significant drops at trigger points (e.g., BL20-high group: 16.5% ± 2.6%).
• Hemodynamic parameters did not exhibit significant changes at these analgesic inadequacy trigger points.

Conclusions:

• Electroencephalographic bicoherence peaks (pBICs) serve as superior indicators of analgesia adequacy during surgery.
• pBICs provide more sensitive detection of inadequate analgesia compared to standard anesthesia monitoring techniques.