title: Regional cerebral glucose metabolism during sevoflurane anaesthesia in healthy subjects studied with positron emission tomography.
abstract: BACKGROUND
  The precise mechanism by which sevoflurane exerts its effects in the human brain remains unknown. In the present study, we quantified the effects of sevoflurane on regional cerebral glucose metabolism (rGMR) in the human brain measured with positron emission tomography.
  
  
  METHODS
  Eight volunteers underwent two dynamic 18F-fluorodeoxyglucose positron emission tomography (PET) scans. One scan assessed conscious-baseline metabolism and the other scan assessed metabolism during 1 minimum alveolar concentration (MAC) sevoflurane anaesthesia. Cardiovascular and respiratory parameters were monitored and bispectral index responses were registered. Statistical parametric maps and conventional regions of interest analysis were used to determine rGMR differences.
  
  
  RESULTS
  All subjects were unconsciousness at 1.0 MAC sevoflurane. Cardiovascular and respiratory parameters were constant over time. In the awake state, rGMR ranged from 0.24 to 0.35 mumol/g/min in the selected regions. Compared with the conscious state, total GMR decreased 56% in sevoflurane anaesthesia. In white and grey matter, GMR was averaged 42% and 58% of normal, respectively. Sevoflurane reduced the absolute rGMR in all selected areas by 48-71% of the baseline (P< or = 0.01), with the most significant reductions in the lingual gyrus (71%), occipital lobe in general (68%) and thalamus (63%). No increases in rGMR were observed.
  
  
  CONCLUSIONS
  Sevoflurane caused a global whole-brain metabolic reduction of GMR in all regions of the human brain, with the most marked metabolic suppression in the lingual gyrus, thalamus and occipital lobe.
authors.affiliation: Department of Neuroanaesthesiology, Aarhus University Hospitals, Noerrebrogade 44, 8000 Aarhus C, Denmark. lise.schlunzen@dadlnet.dk
authors.forename: L
authors.initials: L
authors.lastname: Schlünzen
authors.forename: N
authors.initials: N
authors.lastname: Juul
authors.forename: K V
authors.initials: KV
authors.lastname: Hansen
authors.forename: A
authors.initials: A
authors.lastname: Gjedde
authors.forename: G E
authors.initials: GE
authors.lastname: Cold
mesh_terms: D000328:Adult; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008738:Methyl Ethers / Q000494:pharmacology*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D000077149:Sevoflurane; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000077149:Sevoflurane; D005947:Glucose