title: Comparative evaluation of the cerebral state index and the bispectral index during target-controlled infusion of propofol.
abstract: BACKGROUND
  Cerebral state index (CSI) has recently been introduced as an intra-operative monitor of anaesthetic depth. We compared the performance of the CSI to the bispectral index (BIS) in measuring depth of anaesthesia during target-controlled infusion (TCI) of propofol.
  
  
  METHODS
  Twenty Chinese patients undergoing general anaesthesia were recruited. CSI and BIS, and predicted effect-site concentration of propofol were recorded. The level of sedation was tested by Modified Observer's Assessment of Alertness/Sedation Scale (MOAAS) every 20 s during stepwise increase (TCI, 0.5 microg ml(-1)) of propofol. The loss of verbal contact (LVC) and loss of response (LOR) were defined by MOAAS values of 2-3 and less than 2, respectively. Baseline variability and the prediction probability (P(K)) were calculated for the BIS and CSI. The values of BIS(05) and CSI(05), BIS(50) and CSI(50), BIS(95) and CSI(95) were calculated at each end-point (LVC and LOR).
  
  
  RESULTS
  Baseline variability of CSI was more than that of BIS. Both CSI and BIS showed a high prediction probability for the steps awake vs LVC, awake vs LOR, and LVC vs LOR, and good correlations with MOAAS values.
  
  
  CONCLUSIONS
  Despite larger baseline variation, CSI performed as well as BIS in terms of P(K) values and correlations with step changes in sedation.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Xiangya Hospital, Central Southern University, Changsha 410008, China. zhongtao88@tom.com
authors.forename: T
authors.initials: T
authors.lastname: Zhong
authors.forename: Q L
authors.initials: QL
authors.lastname: Guo
authors.forename: Y D
authors.initials: YD
authors.lastname: Pang
authors.forename: L F
authors.initials: LF
authors.lastname: Peng
authors.forename: C L
authors.initials: CL
authors.lastname: Li
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D001364:Awareness / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol