The Influence Of Vecuronium And Rocuronium On Bispectral Index And Cerebral State Index Under Light Anaesthesia

Objective:In order to know the mechanism of the influence of muscle relaxants on the bispectral index(BIS)and cerebral state index(CSI)all the better,observe the influence of non-depolarization muscle relaxant rocuronium and vecuronium on BIS and CSI,and the influrance of rocuronium with different dose on BIS and CSI in patients under light anaesthetic condition by target-controlled infusion(TCI), with effect-site propofol concentration of 2.5ug/ml,and then analyze the difference between them.Methods:50 adult patients aged between 20-55 undergoing elective surgery under general anesthesia and Classified into American Society of Anesthesiologists(ASA)â… and ASAâ…¡risk groups were included in the study.All patients were given propofol by target-cotrolled infusion(TCI),and the effect site of propofol concentration was set to 4.0ug/ml at first,when the concentration reach 4.0ug/ml,finished the insertion of laryngeal mask airway(LMA),and handle the airway,then resetted the effect site of propofol concentration to 2.5ug/ml,and wait it to reach the setting effect concentration,at the same time,the ulnar nerve was stimulated at the wrist with train-of-four provided by TOF-Guard, and T₁ was stabilized at 100%.Twenty minutes later,randomized these patients into five groups(group 0,A,B,C,D,each group=10 patients),group 0 received 2ml normal saline,and ended the experiment after 20 minutes;group A,B,C,D received a bolus of 1ED₉₀(0.3mg/ml),2ED₉₀(0.6mg/ml),3ED₉₀(0.9mg/ml)rocuronium and 2ED₉₀(0.1mg/ml) vecuronium respectively,and the experiment was finished when T₁ recoveried to 10%.The following variables as VS(vital sign),BIS,f EMG,CSI and T1 were recorded during the experiment.Results.BIS,CSI appeared to decrease in the initial stage and rebound in the final phase after the administration of vecuronium and rocuronium in groups A,B,C and D(P＜0.001),there was no difference between the maximal descendent degrees of BIS and CSI(P＞0.05);the onset time of muscle relaxation is shorter in group B and C than group A (P＜0.05),the time to descend to the lowest of BIS and CSI is earlier in group B and C than group A(P＜0.05),the onset time of muscle relaxation and the time to descend to the lowest of BIS and CSI are similar in group B and C(P＞0.05),there was no difference in the maximal descendent degrees of BIS and CSI in group A,B and C(P＞0.05);the onset time of muscle relaxation is longer in group D than B(P＜0.05),the time to descend to the lowest of BIS and CSI is later in group D than B (P＜0.05),there was no difference in the maximal descendent degrees of BIS and CSI at groupB and D(P＞0.05).During TCI of propofol,BIS and fEMG which were detected by Aspect A-2000 BIS monitor decreased as there was a increasing in the effect-site concentration of propofol,a linear correlation was found between BIS and fEMG,and the correlation of determination(R²)was 0.506.Conclusion:1.Under light anaesthesia,BIS and CSI appeared to decrease in the initial stage and rebound in the final phase,accompanied with the inhibition and recovery of myoseism,and the time to descend to the lowest of BIS and CSI is depended on the onset time of muscle relaxation,after the administration of vecuronium and rocuronium.2.The maximal descendent degrees of BIS and CSI were similar,after giving vecuronium and rocuronium of different dose under light anaesthesia.