title: Effect of bispectral index monitoring on sevoflurane consumption.
abstract: OBJECTIVE
  The bispectral index, a parameter derived from the electroencephalograph, has been shown to correlate with the loss of consciousness and sedation. This study was designed to assess the effects of bispectral index monitoring on sevoflurane and its recovery profiles.
  
  
  METHODS
  Sixty ASA I and II patients undergoing open abdominal surgery were randomized into two groups: one monitored using the bispectral index (Group BIS) and the other without its use (controls). After a standardized induction, anaesthesia was maintained with sevoflurane in both groups. In Group BIS, sevoflurane was titrated to maintain the bispectral index in the range 40-60. In the control group, the administered sevoflurane concentration was adjusted according to the signs of anaesthesia. The end-tidal sevoflurane concentration, bispectral index and routine haemodynamic variables were noted every 5 min during surgery. The consumption of sevoflurane was computed. At the conclusion of surgery operations, the time to 'open eyes on verbal command', 'motor response to verbal command' and Aldrete's score were recorded by a blinded anaesthesiologist.
  
  
  RESULTS
  The difference in the consumption of sevoflurane was not significant between the groups. Bispectral index monitoring was associated with a reduction of 4.73% in sevoflurane usage and 2.19 mL h(-1) was saved.
  
  
  CONCLUSIONS
  Bispectral index monitoring during anaesthesia provides only a small advantage related to the need to monitor the depth of anaesthesia.
authors.affiliation: Kirikkale University, Department of Anaesthesiology and Reanimation, Kirikkale, Turkey. gozde@ada.net.tr
authors.forename: H
authors.initials: H
authors.lastname: Başar
authors.forename: S
authors.initials: S
authors.lastname: Ozcan
authors.forename: U
authors.initials: U
authors.lastname: Buyukkocak
authors.forename: S
authors.initials: S
authors.lastname: Akpinar
authors.forename: A
authors.initials: A
authors.lastname: Apan
mesh_terms: D000005:Abdomen / Q000601:surgery; D000328:Adult; D000762:Anesthesia Recovery Period; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D003243:Consciousness / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D008991:Monitoring, Physiologic; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane