title: Cerebral state index during propofol anesthesia: a comparison with the bispectral index and the A-line ARX index.
abstract: BACKGROUND
  The objective of this study was to prospectively test the Cerebral State Index designed for measuring the depth of anesthesia. The Cerebral State Index is calculated using a fuzzy logic combination of four subparameters of the electroencephalographic signal. The performance of the Cerebral State Index was compared with that of the Bispectral Index and the A-Line ARX Index.
  
  
  METHODS
  This study applied raw data from two previously published clinical protocols. The patients in protocol 1 were given a continuous propofol infusion, 300 ml/h, until 80% of burst suppression occurred. In protocol 2, a stepwise increased target-controlled infusion of propofol was administered to patients until loss of response to noxious stimuli while the Observer's Assessment of Alertness and Sedation was registered every 4 min. The Cerebral State Index was calculated off-line from the recorded electroencephalographic data. The Spearman rank correlation coefficient between electronic indices and the effect site concentration of propofol was calculated along with the prediction probability of each index to predict the Observer's Assessment of Alertness and Sedation level.
  
  
  RESULTS
  The Spearman rank correlation coefficients between the Cerebral State Index, Bispectral Index, and A-Line ARX Index and the propofol effect site concentration were -0.94, -0.89, and -0.82, respectively, in protocol 1, whereas the prediction probability values between the Cerebral State Index, Bispectral Index, and A-Line ARX Index and the Observer's Assessment of Alertness and Sedation score in protocol 2 were 0.92, 0.93, and 0.91, respectively.
  
  
  CONCLUSIONS
  The Cerebral State Index detects well the graduated levels of propofol anesthesia when compared with the propofol effect site concentration and the Observer's Assessment of Alertness and Sedation score.
authors.affiliation: Department of Cardiac Anesthesia, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Erik W
authors.initials: EW
authors.lastname: Jensen
authors.forename: Hector
authors.initials: H
authors.lastname: Litvan
authors.forename: Miren
authors.initials: M
authors.lastname: Revuelta
authors.forename: Bernardo E
authors.initials: BE
authors.lastname: Rodriguez
authors.forename: Pere
authors.initials: P
authors.lastname: Caminal
authors.forename: Pablo
authors.initials: P
authors.lastname: Martinez
authors.forename: Hugo
authors.initials: H
authors.lastname: Vereecke
authors.forename: Michel M R F
authors.initials: MM
authors.lastname: Struys
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000771:Anesthesia, Intravenous / Q000706:statistics & numerical data; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D004569:Electroencephalography / Q000187:drug effects* / Q000706:statistics & numerical data; D005260:Female; D017143:Fuzzy Logic; D006801:Humans; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology*; D011446:Prospective Studies
chemical_list: D015742:Propofol