title: Risk factors for the occurrence of electroencephalogram abnormalities during induction of anesthesia with sevoflurane in nonepileptic patients.
abstract: BACKGROUND
  The aim of this prospective study was to determine the risk factors of epileptiform discharge during induction with sevoflurane in healthy adult patients.
  
  
  METHODS
  Forty adult patients with American Society of Anesthesiologists physical status I were randomly allocated to one of four groups. Group A: Patients breathed 8% sevoflurane in oxygen (8 l/min) via a prefilled circuit. End-tidal sevoflurane was maintained at 4%. Tracheal intubation was performed at the third minute after cisatracurium injection. Group B: The anesthesia protocol was similar, but a vital capacity technique was performed. Group C: Patients were anesthetized as in group A but were hyperventilated. Group D: Patients were anesthetized as in group A, but end-tidal sevoflurane was maintained at 2%. An electroencephalogram was recorded before and during induction up to 11 min after the start of induction. Statistical analysis was performed with Statview 5.0 (SAS Institute Inc., Cary, NC) for multivariate analysis.
  
  
  RESULTS
  Twelve patients experienced epileptiform discharges. Risk factors were female sex (odds ratio, 12.60; 95% confidence interval, 1.46-135), delay to the occurrence of beta waves (odds ratio, 0.92; 95% confidence interval, 0.86-0.99), and end-tidal sevoflurane (odds ratio, 8.78; 95% confidence interval, 1.12-69). Epileptiform discharges were not associated with significant hemodynamic or Bispectral Index variations.
  
  
  CONCLUSIONS
  Induction with sevoflurane may result in epileptiform electroencephalographic activity. Only electroencephalographic monitoring allows the diagnosis. Risk factors are mainly female sex, short delay to onset of anesthesia, and high alveolar sevoflurane concentration. Induction with high sevoflurane concentration is controversial mainly in women.
authors.affiliation: Département d'anesthésie réanimation 4, France. benjamin.julliac@chu-bordeaux.fr
authors.forename: Benjamin
authors.initials: B
authors.lastname: Julliac
authors.forename: Dominique
authors.initials: D
authors.lastname: Guehl
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chopin
authors.forename: Pierre
authors.initials: P
authors.lastname: Arne
authors.forename: Pierre
authors.initials: P
authors.lastname: Burbaud
authors.forename: François
authors.initials: F
authors.lastname: Sztark
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Cros
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D002245:Carbon Dioxide / Q000097:blood; D003071:Cognition / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000009:adverse effects*; D012307:Risk Factors; D000077149:Sevoflurane; D012727:Sex Characteristics
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane