title: Effect of ketamine on bispectral index during propofol--fentanyl anesthesia: a randomized controlled study.
abstract: BACKGROUND
  The Bispectral Index (BIS) helps in the assessment of the depth of hypnosis. N-methyl-D-aspartic acid antagonist, ketamine, has been used in various doses to decrease postoperative morphine consumption. The purpose of our study was to compare the effects of two different doses (0.5 mg/kg and 0.2 mg/kg) of ketamine on BIS values.
  
  
  METHODS
  Forty-five ASA I or II patients undergoing general anesthesia were included in this double-blind, prospective, control trial and randomly allocated into three groups. After induction of anesthesia and tracheal intubation, a propofol infusion was started and titrated to attain BIS values of around 40. After five minutes of stable BIS values and in the absence of any surgical stimulus, patients received either 0.5 mg/kg of ketamine (Group K1) or 0.2 mg/kg of ketamine (Group K2) or normal saline (Group N) as bolus intravenously. BIS values were recorded for the next 15 minutes, at five-minutes interval.
  
  
  RESULTS
  Mean BIS values were significantly increased in Group K1 (63.5) while Group K2 (42.0) failed to show any significant rise. BIS values in Group K2 were comparable to those in Group N.
  
  
  CONCLUSIONS
  Thus, under stable propofol anesthesia, a bolus ofketamine 0.5 mg/kg increases BIS values while ketamine 0.2 mg/kg does not.
authors.affiliation: Department of Anesthesiology, Perioperative Medicine and Pain, Apollo Gleneagles Hospitals. saikatsg@gmail.com
authors.forename: Saikat
authors.initials: S
authors.lastname: Sengupta
authors.forename: Simantika
authors.initials: S
authors.lastname: Ghosh
authors.forename: Amitava
authors.initials: A
authors.lastname: Rudra
authors.forename: Palash
authors.initials: P
authors.lastname: Kumar
authors.forename: Gaurab
authors.initials: G
authors.lastname: Maitra
authors.forename: Tanmoy
authors.initials: T
authors.lastname: Das
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000778:Anesthetics, Dissociative / Q000008:administration & dosage* / Q000009:adverse effects* / Q000627:therapeutic use; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D056805:Consciousness Monitors; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005283:Fentanyl; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage* / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control; D011229:Preanesthetic Medication; D015742:Propofol; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D007649:Ketamine; D005283:Fentanyl; D015742:Propofol