title: Hyperventilation accelerates the rise of arterial blood concentrations of desflurane in gynecologic patients.
abstract: OBJECTIVE
  Under a constant inspired concentration, the uptake of a volatile anesthetic into the arterial blood should mainly be governed by alveolar ventilation, according to the assumption that the patient's cardiac output remains stable during anesthesia. We investigated whether ventilation volume affects the rate of desflurane uptake by examining arterial blood concentrations.
  
  
  METHODS
  Thirty female patients were randomly allocated into the following three groups: hyperventilation, normal ventilation and hypoventilation. Hemodynamic variables were measured using a Finometer, inspiratory and end-tidal concentrations of desflurane were measured by infrared analysis, and the desflurane concentration in the arterial blood (Ades) was analyzed by gas chromatography.
  
  
  RESULTS
  During the first 10 minutes after the administration of desflurane, the Ades was highest in the hyperventilation group, and this value was significantly different from those obtained for the normal and hypoventilation groups. In addition, hyperventilation significantly increased the slope of Ades-over-time during the first 5 minutes compared with patients experiencing normal ventilation and hypoventilation, but there were no differences in these slopes during the periods from 5-10, 10-20 and 20-40 minutes after the administration of desflurane. This finding indicates that there were no differences in desflurane uptake between the three groups after the first 5 minutes within desflurane administration.
  
  
  CONCLUSIONS
  Hyperventilation accelerated the rate of the rise in Ades following desflurane administration, which was time-dependent with respect to different alveolar ventilations levels.
authors.affiliation: Department of Anesthesiology, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Chih-Cherng
authors.initials: CC
authors.lastname: Lu
authors.forename: Tso-Chou
authors.initials: TC
authors.lastname: Lin
authors.forename: Che-Hao
authors.initials: CH
authors.lastname: Hsu
authors.forename: Mu-Hsien
authors.initials: MH
authors.lastname: Yu
authors.forename: Ta-Liang
authors.initials: TL
authors.lastname: Chen
authors.forename: Ruei-Ming
authors.initials: RM
authors.lastname: Chen
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Ku
authors.forename: Shung-Tai
authors.initials: ST
authors.lastname: Ho
mesh_terms: D000328:Adult; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000097:blood*; D002849:Chromatography, Gas; D000077335:Desflurane; D005260:Female; D005831:Genital Diseases, Female / Q000097:blood* / Q000601:surgery; D006801:Humans; D006985:Hyperventilation / Q000097:blood*; D007040:Hypoventilation / Q000097:blood; D007530:Isoflurane / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D013997:Time Factors; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D000077335:Desflurane; D007530:Isoflurane