The Application Of Nicolet One Brain Function Monitors In Propofol Sedation Monitoring

Objectives 1. To evaluate the relevance of bispectral index (Bispectral index, BIS), the Ramsay score and the amount of propofol used to verify the objectivity of BIS.2. To measure the dynamic changes of EEG parameter by using Nicolet One brain function monitor quantitative EEG in different brain regions in the process of propofol sedation and withdrawal 3. To evaluate whether Nicolet One brain function monitors are available for monitoring depth of propofol sedation through analyzing the relevance of the different frequency EEG parameter in different brain regions and Ramsay score.Methods First disable all sedatives before the experiment, and infuse propofol intravenously until the patients are fully conscious. Propofol infusion begins with Bμg.kg-1.min-1, and increases propofol infusion volume 8μg-kg-1.min-1 every 15min. When the BIS is less than 40 or propofol maintenance dose reaches 32-kg-1.min-1, propofol infusion should be stopped. Record the BIS, vital signs as well as ramsay score at different observation points. During the process, we continuously record the EEG parameter, observe changes of vital signs, BIS, Ramsay score, and EEG parameter and carry on the relevant analysis. Results During propofol sedation and withdrawal, BIS show significantly negative correlation with Ramsay scores(r=-0.85and-0.81, P<0.01). Different frequency EEG power shows obvious dynamic changes in various brain regions, especially d band. In the subsequent correlation analysis, it is found that, the absolute values of the correlation coefficient of F3, F4 (left and right frontal) d band power and Ramsay score both reach 0.89. During propofol withdrawal, the figures are 0.85and 0.86, which are higher than the absolute value of correlation coefficient of the BIS and Ramsay score. The absolute values of percentage of d band power, ratio of (θ+δ)/(a+β) and Ramsay score range from 0.84 to 0.87 and from 0.76 to 0.86 during propofol sedation.While during propofol withdrawal, the figures are from 0.66 to 0.78 and from 0.63 to 0.72, which are close to the absolute value of correlation coefficient of the BIS and Ramsay score. The cost of each monitoring is only 4 yuan.Conclusion 1. BIS and the Ramsay score are well associated and BIS is a reliable and objective means to evaluate the depth of sedation.2.During propofol sedation and withdrawal, different frequency areas of the brain shows a significant EEG power dynamics, particularly d band.3.d band power about left and right frontal can be used as an objective evaluation and better indicators of the level of sedation and Nicolet One monitor brain function analysis of quantitative EEG features can be used in monitoring depth of propofol sedation.4. Nicolet One monitor brain function in monitoring depth of propofol sedation has obvious economic advantages.