title: [Sudden increase in bispectral index during propofol anesthesia in three patients].
abstract: We report 3 patients who developed a sudden unpredicted increase in bispectral index (BIS) value during propofol and fentanyl anesthesia. The patients were induced with propofol 2-mg.kg-1 and fentanyl 2-micrograms.kg-1 and muscle relaxation was obtained by vecuronium 0.12-mg.kg-1. During induction of anesthesia, BIS value went down to below 50 in all three cases, and anesthesia was maintained by continuous infusion of propofol at a rate of 5 mg.kg-1.hr-1 and intermittent administration of fentanyl. Forty to sixty min after starting the operation, BIS value increased suddenly (up to 80) and the body movement of the patients was observed. The serum concentration of propofol was approximately 2.5 micrograms.ml-1. All patients were successfully treated with increasing the infusion rate of propofol and additional administration of fentanyl. No clear recall or explicit memory during operation was observed after anesthesia, but, anesthesiologists might have to pay more attention to unpredictable changes of anesthetic depth during propofol anesthesia using target controlled infusion.
authors.affiliation: Medical Corps, 1st Air Wings, Japan Air Self Defense Force, Hamamatsu 432-8554.
authors.forename: Maiko
authors.initials: M
authors.lastname: Satomoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Aoki
authors.forename: Morikuni
authors.initials: M
authors.lastname: Tobita
authors.forename: Nao
authors.initials: N
authors.lastname: Shiohara
authors.forename: Yushi
authors.initials: Y
authors.lastname: Adachi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Higuchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Satoh
mesh_terms: D000328:Adult; D000771:Anesthesia, Intravenous; D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D001364:Awareness; D005260:Female; D005283:Fentanyl; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015742:Propofol / Q000097:blood; D013514:Surgical Procedures, Operative
chemical_list: D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D005283:Fentanyl; D015742:Propofol