title: Beat-by-beat cardiovascular index to predict unexpected intraoperative movement in anesthetized unparalyzed patients: a retrospective analysis.
abstract: OBJECTIVE
  Unexpected intraoperative movement may be detrimental during delicate surgery. This study tested retrospectively an algorithm based on beat-by-beat circulatory variables (incorporated into a Cardiovascular depth of anesthesia index: CARDEAN in relationship to unexpected movement, and compared its performance to that of the electroencephalogram (EEG)-derived index: BIS-XP 4.0.
  
  
  METHODS
  40 ASA I or II patients presenting for knee surgery had EEG (BIS XP 4.0), beat-by-beat (Finapres) finger non-invasive blood pressure (BP), conventional brachial BP and electrocardiogram (EKG) monitors attached. Anesthesia was induced and maintained with propofol and remifentanil. Before incision, the propofol concentration was set to maintain BIS < 60. From incision to emergence, the anesthesiologist was denied access to BIS or Finapres. Anesthesia adjustment was titrated at the discretion of the anesthesiologist according to conventional signs only: brachial BP, EKG, eyelash reflex, movement. Occurrences of movement and eye signs (divergence of eyeballs, tears, corneal reflex, eyelash reflex) were observed. The CARDEAN algorithm was written retrospectively and tested vs. BIS.
  
  
  RESULTS
  11 movements occurred in 8 patients. CARDEAN > 60 predicted movement in 30% of the cases, 15 to 274 s before movement (sensitivity: 100%, specificity: 95%; relative operating curve ROC = 0.98; prediction probability pk = 0.98). BIS > 60 predicted movement in 19% of cases (sensitivity: 64%; specificity: 94%, ROC: 0.85, pk: 0.85).
  
  
  CONCLUSIONS
  Retrospectively, a cardiovascular index predicted unexpected intraoperative movements. Prospective validation is needed.
authors.affiliation: Alpha-2 SARL, Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: Cividjian
authors.forename: J Y
authors.initials: JY
authors.lastname: Martinez
authors.forename: E
authors.initials: E
authors.lastname: Combourieu
authors.forename: P
authors.initials: P
authors.lastname: Precloux
authors.forename: A M
authors.initials: AM
authors.lastname: Beraud
authors.forename: Y
authors.initials: Y
authors.lastname: Rochette
authors.forename: M
authors.initials: M
authors.lastname: Cler
authors.forename: L
authors.initials: L
authors.lastname: Bourdon
authors.forename: J
authors.initials: J
authors.lastname: Escarment
authors.forename: L
authors.initials: L
authors.lastname: Quintin
mesh_terms: D000465:Algorithms; D000758:Anesthesia / Q000379:methods*; D018681:Anesthetics, General / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects*; D001795:Blood Pressure Determination / Q000379:methods*; D004569:Electroencephalography / Q000187:drug effects / Q000379:methods; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D009068:Movement / Q000187:drug effects*; D010243:Paralysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D018681:Anesthetics, General