The Application Of Electroencephalogram In The Evaluation Of The Analgesia Degree Of General Anesthesia

Part I Effect of propofol combined with different concentration of remifentanil on quantitative pharmaco-EEGObjective: The evaluation of the degree of analgesia in general anesthesia is lack of effective means.This passage is to observe the effect of propofol combined with different doses of remifentanil on Quantitative pharmaco-EEG and find out the good correlation between pain and EEG.Methods: 60 patients undergoing abdominal gastrointestinal tumor resection under general anesthesia are proposed.After entering the operating room,ECG and Quantitative pharmaco-EEG were monitored.Induced by vecuronium,propofol,remifentanil,patients were divided into group A(1 ng / ml),group B(3 ng / ml)and group C(5 ng / ml)according to the dose of remifentanil.The bispectral index(BIS)was maintained within the range of 45-55.The Quantitative pharmaco-EEG signals were collected before intubation,1 min after intubation,1 min before operation,1 min after operation and after the addition of fentanyl.Results: Compared with before intubation,the percentage of ?and ? band power increased after intubation and skin incision in all brain regions,and the change of ?band in the right fortal and? band in the left fortal and top at tracheal intubation is more obvious than that at skin incision.Compared with the intubation and after the skin incision,the percentage of ?and ? band power decreased after the addition of fentanyl.Groups comparison of n1,n3,the percentage of ?and ? band power is group A> group B > group C.Compared with before intubation,the percentage of ?band power decreased after intubation and skin incision,and there was no significant difference in the changes of tracheal intubation and skin incision except the left frontal cortex.Compared with the intubation and after the skin incision,the percentage of ? band power increased after the addition of fentanyl.Groups comparison of n1,n3,the percentage of?band power in the left frontal brain region is group A < group C,group B < group C,,the difference between the other brain areas was not obvious.Compared with the intubation,the percentage of ? band power increased,but it decreased in some brain regions.When compared between groups,the percentage of ? band power is group A> group B and group A> group C in the left and right frontal area at the tracheal,and group A<group B in the left top and right occipital brain area.Conclusion: Under the same level of sedation,nociceptive stimulation can cause significant changes in EEG..The changes of ?,? and ?band were closely related to the process of nociceptive stimulus and the analgesic can cancel the EEG changes.The changes of ? and ? band are closely related to the dose of analgesics.Synthesis of these changes may provide a reference for the evaluation of analgesia during anesthesia.Part II Clinical value of pain rating inde in evaluating analgesic effect during general anesthesiaObjective: To primarily investigate the clinical value of pain rating index(PRi)in evaluating analgesic effect during general anesthesia.Methods: 20 patients undergoing elective abdominal surgery under general anesthesia,ASA1-11,weight 50-80 kg.Target-controlled infusion of propofol(initial plasma target concentration of 1 ug / ml)and remifentanil(2 ng / ml)were used for induction of general anesthesia.Adjust the concentration of propofol and maintain BIS 40-60.Intravenous injection of vecuronium,tracheal intubation and mechanical ventilation.The changes of BIS,PRi,SBP,DBP and HR were recorded before and after tracheal intubation,skin incision and the addition of fentanyl.Results: The results showed that the SBP,DBP,HR and PRi were significant increased in both tracheal intubation and skin incision(P<0.05).SBP,DBP,HR and PRi were decreased after the addition of fentanyl(P<0.05).No significant changes of BIS were found in both tracheal intubation and skin incision(P>0.05).BIS decreased after fentanyl administration(P<0.05).Conclusion: PRi can be used to evaluate the degree of analgesia during general anesthesia,which has some guiding significance for clinical practice.