title: Cerebral blood flow change during volatile induction in large-dose sevoflurane versus intravenous propofol induction: transcranial Doppler study.
abstract: BACKGROUND
  The impact of volatile induction using large-dose sevoflurane (VI-S) on cerebral blood flow has not been well investigated. The present study compared the changes in cerebral blood flow of middle cerebral artery using transcranial Doppler (TCD) during VI-S and conventional induction using propofol.
  
  
  METHODS
  Patients undergoing elective lumbar discectomy were randomly allocated to receive either sevoflurane (8%, Group VI-S, n = 11) or target-controlled infusion of propofol (effect site concentration, 3.0 µg/ml; Group P, n = 11) for induction of anesthesia. The following data were recorded before and at 1, 2, and 3 min after commencement of anesthetic induction (T0, T1, T2, and T3, respectively): mean velocity of the middle cerebral artery (VMCA) by TCD, mean blood pressure (MBP), heart rate, bispectral index score (BIS) and end-tidal CO2 (ETCO2). Changes in VMCA and MBP from their values at T0 (ΔVMCA and ΔMBP) at T1, T2, and T3 were also determined.
  
  
  RESULTS
  BISs at T1, T2 and T3 were significantly less than that at T0 in both groups (P < 0.05). ΔVMCA in Group VI-S at T2 and T3 (18.1% and 12.4%, respectively) were significantly greater than those in Group P (-7.6% and -19.8%, P = 0.006 and P < 0.001, respectively), whereas ETCO2 and ΔMBP showed no significant intergroup difference.
  
  
  CONCLUSIONS
  VI-S using large-dose sevoflurane increases cerebral blood flow resulting in luxury cerebral flow-metabolism mismatch, while conventional propofol induction maintains cerebral flow-metabolism coupling. This mismatch in VI-S may have to be considered in clinical application of VI-S.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Hwa Sung
authors.initials: HS
authors.lastname: Jung
authors.affiliation: Department of Anesthesiology and Pain Medicine, Konyang University Hospital, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Tae-Yun
authors.initials: TY
authors.lastname: Sung
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chung-Ang University Medical Center, Chung-Ang University School of Medicine, Seoul, Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Anesthesiology and Pain Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Jin Sun
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Konkuk University Medical Center, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Tae-Yop
authors.initials: TY
authors.lastname: Kim
keywords: Cerebral blood flow; Sevoflurane; Volatile induction and maintenance of anesthesia