title: Bispectral Index Scale variations in patients diagnosed with brain death.
abstract: BACKGROUND
  Brain death (BD) is defined as the total irreversible loss of brain stem function. According to the Greek legislation, BD diagnosis is based on clinical criteria that test brain stem function. Bispectral Index Scale (BIS), a parameter derived from a mathematical analysis of the electroengephalogram depicts brain activity. The aim of our study was to record BIS alterations in brain-dead patients.
  
  
  METHODS
  Thirty-five brain dead patients according to the clinical criteria were included in this study. All patients were hemodynamically stable, normothermic, and normocapnic, free of oxygenation disturbances and electrolyte abnormalities. Continuous BIS monitoring (BIS XP, A-2000, Aspect Medical Systems, Newton, Mass, USA) was performed in all patients for periods ranging from 24 to 36 hours.
  
  
  RESULTS
  BIS values were 0 for the majority of the study period in all patients. However, in 23 patients the BIS value exceeded 30 for more than 30 minutes. This increase could not be attributed to any external stimulation.
  
  
  CONCLUSIONS
  BIS is a noninvasive, easily interpreted method to monitor cerebral activity. According to our results, BIS could be helpful in BD confirmation but cannot replace the valid clinical tests, which are consistent with Greek legislation for this diagnosis.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, AHEPA University Hospital, Thessaloniki, Greece. bfyntan@yahoo.com
authors.forename: B
authors.initials: B
authors.lastname: Fyntanidou
authors.forename: V
authors.initials: V
authors.lastname: Grosomanidis
authors.forename: Z
authors.initials: Z
authors.lastname: Aidoni
authors.forename: G
authors.initials: G
authors.lastname: Thoma
authors.forename: M
authors.initials: M
authors.lastname: Giakoumis
authors.forename: E
authors.initials: E
authors.lastname: Kiurzieva
authors.forename: C
authors.initials: C
authors.lastname: Skourtis
mesh_terms: D000328:Adult; D001833:Body Temperature Regulation; D001921:Brain / Q000503:physiopathology*; D001926:Brain Death / Q000175:diagnosis* / Q000503:physiopathology; D058256:Brain Waves; D056805:Consciousness Monitors; D004569:Electroencephalography / Q000295:instrumentation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors