title: The effects of ketamine and rocuronium on the A-Line auditory evoked potential index, Bispectral Index, and spectral entropy monitor during steady state propofol and remifentanil anesthesia.
abstract: BACKGROUND
  The authors studied the effects of ketamine and rocuronium on the Bispectral Index, A-Line auditory evoked potential index, state entropy, and response entropy during a calculated steady state anesthesia with propofol and remifentanil.
  
  
  METHODS
  After ethics committee approval, 42 patients were allocated to four groups. Baseline measurements were performed after implementing a calculated steady state anesthesia with propofol and remifentanil. The control group received no additional medication. The ketamine group received a bolus and continuous infusion of ketamine. The rocuronium group received a bolus of rocuronium. The rocuronium-ketamine group received both. All data were stored during 15 min after baseline. After inspection of the raw data, the authors conducted an explorative statistical analysis.
  
  
  RESULTS
  No significant changes were found in the control group for any of the monitors. Mean values decreased in the rocuronium group for the A-Line auditory evoked potential index, Bispectral Index, and response entropy, but not for state entropy. In the ketamine group, the A-Line auditory evoked potential index and Bispectral Index did not change significantly, but state and response entropy increased. In the rocuronium-ketamine group, the A-Line auditory evoked potential index and Bispectral Index did not decrease as found in the rocuronium group. Response and state entropy increased significantly.
  
  
  CONCLUSIONS
  The response of all monitors after ketamine administration is not affected by simultaneous administration of rocuronium. Interpretation of all studied indices must be done cautiously while taking into account the clinical setting during measurement.
authors.affiliation: Department of Anesthesiology, University Hospital, Ghent, Belgium. hugo.vereecke@ugent.be
authors.forename: Hugo E M
authors.initials: HE
authors.lastname: Vereecke
authors.forename: Ann L
authors.initials: AL
authors.lastname: Vanluchene
authors.forename: Eric P
authors.initials: EP
authors.lastname: Mortier
authors.forename: Karel
authors.initials: K
authors.lastname: Everaert
authors.forename: Michel M R F
authors.initials: MM
authors.lastname: Struys
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000732:Androstanols; D000771:Anesthesia, Intravenous; D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004562:Electrocardiography / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D019277:Entropy; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005260:Female; D006801:Humans; D007649:Ketamine; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D003473:Neuromuscular Nondepolarizing Agents; D010100:Oxygen / Q000097:blood; D010880:Piperidines; D015742:Propofol; D000077208:Remifentanil; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology; D000077123:Rocuronium
chemical_list: D000732:Androstanols; D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines; D007649:Ketamine; D000077208:Remifentanil; D010100:Oxygen; D000077123:Rocuronium; D015742:Propofol