title: Arterial blood concentration of sevoflurane during single-breath induction and tracheal intubation in gynecologic patients.
abstract: OBJECTIVE
  To investigate sevoflurane blood concentrations on loss of consciousness during single-breath induction and ensuing tidal volume ventilation.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Operating room, medical center.
  
  
  METHODS
  12 ASA physical status I and II women scheduled for for gynecologic surgery with general anesthesia.
  
  
  METHODS
  All patients were instructed in the vital capacity technique for inhalation induction with primed inspired sevoflurane greater than 7% in 6 L per minute oxygen. Immediately after loss of consciousness, assisted tidal volume ventilation with a fixed 3.5% of sevoflurane was applied for 9 minutes. Tracheal intubation was performed for each patient following succinylcholine 1.5 mg/kg.
  
  
  METHODS
  Inspired and end-expired sevoflurane concentration, blood pressure, and heart rate were recorded. Meanwhile, arterial blood samples were collected via a radial arterial catheter on loss of consciousness as the 0 minute and at the following 1.5th, 3rd, 4.5th, 6th, and 9th minute and determined for sevoflurane concentrations by gas chromatography.
  
  
  RESULTS
  All 12 patients achieved vital capacity induction uneventfully. The mean time of loss of consciousness was 63.0 +/- 16.6 seconds. The arterial blood concentration of sevoflurane was 1.65% +/- 0.53% on loss of consciousness, equaling to that (1.67% +/- 0.26%) at the third-minute ventilation of 3.5% sevoflurane. The blood concentration at the ninth minute was 2.07% +/- 0.26%.
  
  
  CONCLUSIONS
  The depth of sevoflurane after 9 minutes of ventilation of 3.5% sevoflurane is not sufficient to suppress intubation-induced hemodynamic response.
authors.affiliation: Department of Anesthesiology, Tri-Service General Hospital National Defense Medical Center, Taipei, Taiwan.
authors.forename: Tso-Chou
authors.initials: TC
authors.lastname: Lin
authors.forename: Chih-Cherng
authors.initials: CC
authors.lastname: Lu
authors.forename: Chi-Yuan
authors.initials: CY
authors.lastname: Li
authors.forename: Cheng-Chang
authors.initials: CC
authors.lastname: Chang
authors.forename: Shung-Tai
authors.initials: ST
authors.lastname: Ho
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000097:blood*; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D013509:Gynecologic Surgical Procedures; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods; D008738:Methyl Ethers / Q000008:administration & dosage / Q000097:blood*; D011446:Prospective Studies; D000077149:Sevoflurane; D013990:Tidal Volume / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome; D014474:Unconsciousness
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane