Calculating BIS Level Of Lack Of Recall Of Music Played To Outpatients Undergoing Painless Oocyte Retrieval During Anesthesia Recovery Period Using Sequential Method And CRM

Objective:The aim of this study was to explore BIS50 and BIS95(BIS levels for 50% or 95% patients of lack recall of music)during recovery period using sequential method and continuous reassessment method.Our study was based on high-risk groups(young female patients)of intraoperative awareness.In addition,we intended to compare the result of this study with previous study of combined intravenous and inhaled anesthesia,analyze the reasons that may cause the differences and make hints and suggestions for clinical work.Methods:A prospective clinical trial was performed on young female patients who undergoing painless oocyte retrieval with total intravenous anesthesia.The clinical trial was approved by ethics committee of the First Bethune Hospital of Jilin University and registered in China Clinical Trial Registry(Registration Number: ChiCTR 1800017716).A piece of melody was played randomly for the patients through the same in-ear headphone as the operation starting.When the operation ended and BIS value reached diverse target values,the music was stopped.An anesthesiologist asked every patient some related questions and judged whether awareness occurring at different stages,including: the moment regaining consciousness,3 days after the operation and 30 days after the operation.It is divided into two stages.The first stage adopted sequential method and probit analysis to calculate BIS50 and estimated BIS95 when they could not hear external music stimuli;while,in the second stage,BIS95 was reevaluated by continuous reassessment method.Results:78 patients who met the admission criteria were included in the study,and 11 patients who did not meet the requirements were excluded between August 15,2018 and December 15,2018.The whole process could be divided into two parts.There were 27 patients in the first stage and 40 patients in the second stage.During the first stage,13 people heard the music and could accurately recall it;during the second stage,4 people heard the music and could accurately recall it.None of these 17 patients who heard the music had any psychiatric trauma or stress disorder after operation.BIS50(95%CI)for lack recall of music was estimated to be 74.8(71.2-78.6).BIS95(95%CI)for lack recall of music was estimated to be 65(64.6-67.2).Conclusion:In regard to outpatients who underwent painless oocyte retrieval,50% of them could recall external music stimuli with BIS value of 75;5% of them could recall external music stimuli with BIS value of 65 during recovery period of total intravenous anesthesia.