title: The effect of bispectral index monitoring on end-tidal gas concentration and recovery duration after outpatient anesthesia.
abstract: We performed this study to determine whether instituting monitoring of bispectral index (BIS) throughout an entire operating room would affect end-tidal gas concentration (as a surrogate for anesthetic use) or speed of recovery after outpatient surgery. Primary caregivers (n = 69) were randomly assigned to a BIS or non-BIS Control group with cross-over at 1-mo intervals for 7 mo. Data were obtained in all outpatients except for those having head-and-neck surgery. Mean end-tidal gas concentration and total recovery duration were compared by unpaired t-test. Overall, 469 patients (80%) received propofol for induction and sevoflurane for maintenance. This homogeneous group was selected for statistical analysis. Mean end-tidal sevoflurane concentration was 13% less in the BIS group (BIS, 1.23%; Control, 1.41%; P < 0.0001); differences were most evident when anesthesia was administered by first-year trainees. Mean BIS values were 47 in the BIS-Monitored group. Total recovery was 19 min less with BIS monitoring in men (BIS group, 147 min; Controls, 166 min; P = 0.035), but not different in women. We conclude that routine application of BIS monitoring is associated with a modest reduction in end-tidal sevoflurane concentration. In men, this may correlate with a similar reduction (11%) in recovery duration.
authors.affiliation: Department of Anesthesiology, University of Washington School of Medicine, Seattle, Washington 98195, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Pavlin
authors.forename: J Y
authors.initials: JY
authors.lastname: Hong
authors.forename: P R
authors.initials: PR
authors.lastname: Freund
authors.forename: M E
authors.initials: ME
authors.lastname: Koerschgen
authors.forename: J O
authors.initials: JO
authors.lastname: Bower
authors.forename: T A
authors.initials: TA
authors.lastname: Bowdle
mesh_terms: D000328:Adult; D000368:Aged; D000556:Ambulatory Surgical Procedures; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000493:pharmacokinetics; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011446:Prospective Studies; D011785:Quality Assurance, Health Care; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane