ABSTRACT
OBJECTIVE@#To evaluate the accuracy of cerebral state index (CSI) as an indicator of anesthesia depth in patients in the induction of anesthesia with target-controlled infusion of propofol.@*METHODS@#Forty ASA (American Society of Anesthesiologists) I approximately II patients scheduled for an operation under general anesthesia were anesthetized with target-controlled infusion of propofol. Target plasma concentration was 0. 5 mg/L at the beginning, and increased by 0. 5 mg/L every 5 minutes, till 5 minutes after the level of MOAA/S (modified observer's assessment of alertness/sedation) was 0. The CSI, mean arterial pressure (MAP), heart rate (HR), MOAA/S level, and the effect-site concentration of propofol were recorded.@*RESULTS@#(1) CSI values declined with the decrease of MOAA/S levels. CSI values were statistically different between level 0 and 1, level 1 and 2, level 3 and 4, level 4 and 5 of MOAA/S (P 0.05). (2) The spearman rank correlation co-efficients between CSI, MAP, HR and the level of MOAA/S were 0.929, 0.421, and 0.085, respectively. The prediction probabilities (Pk) to differentiate different levels of MOAA/S for CSI, MAP, and HR were 0.94, 0.67, and 0.54, respectively. (3) There was linear regression relationship between CSI and the effect-site concentration of propofol (the coefficient of determination R2 was 0. 833, P < 0.01).@*CONCLUSION@#During the induction of patients with target-controlled infusion of propofol, the CSI is accurate as an indicator of awakeness and different levels of consciousness after anesthesia, and can reliably predict the anesthesia depth.
Subject(s)
Adult , Female , Humans , Male , Adjuvants, Anesthesia , Anesthesia, General , Anesthetics, Intravenous , Cerebral Cortex , Physiology , Monitoring, Intraoperative , Methods , PropofolABSTRACT
OBJECTIVE@#To examine the predicted effect-site concentration of propofol at two clinical end-points: loss of verbal contact (LVC) and loss of consciousness (LOC), and to explore the relationship between bispectral index (BIS) values, cerebral state index (CSI) values and the predicted effect-site concentration during the target-controlled infusion of propofol.@*METHODS@#In 20 patients during the target-controlled infusion of propofol, the propofol infusion was set at an initial effect-site concentration of 0.5 mg/L, and increased by 0.5 mg/L every 5 min until 5 min after the modified observer's assessment of alertness/sedation scale (OAA/S) values reached zero. The predicted effect-site concentration of propofol, the values of CSI and BIS were recorded, and the sedation level was examined by the modified OAA/S every 20s. The predicted effect-site concentrations of propofol in target-controlled infusion (TCI) system were recorded when they increased by more than 0.1 mg/L. The predicted effect-site concentrations of propofol and the values of BIS and CSI at LVC and LOC in 5%, 50% and 95% of the patients were calculated.@*RESULTS@#There was good linearity between BIS and the predicted effect-site concentration of propofol (R(2)=0.787), as well as between CSI and the predicted effect-site concentration of propofol (R(2)=0.792). The predicted effect-site concentrations of propofol at LVC in 5%, 50% and 95% of the patients were 1.1,1.8 and 2.4 mg/L, respectively. The values of BIS and CSI at LVC in 5%, 50% and 95% of the patients were 79.2, 69.2 and 59.2; 74.9, 65.9 and 56.8, respectively. The predicted effect-site concentrations of propofol at LOC in 5%, 50% and 95% of the patients were 1.5, 2.5 and 3.4 mg/L, respectively. At LOC, the values of BIS and CSI in 5%, 50% and 95% of the patient were 73.6, 57.1 and 40.6; 65.2, 54.8 and 44.3, respectively.@*CONCLUSION@#During target-controlled infusion of propofol, LVC and LOC occur within a definite range of predicted effect-site concentrations. There is the good linearity between BIS, CSI and the predicted effect-site concentrations of propofol. CSI may be more useful than BIS in predicting LVC and LOC.