title: Signal persistence of bispectral index and state entropy during surgical procedure under sedation.
abstract: BACKGROUND
  Bispectral index (BIS) and state entropy (SE) are prone to artifacts, especially due to electrocautery (EC). We compared the incidence of artifacts in BIS and SE during surgery under local anesthesia and sedation.
  
  
  METHODS
  28 females undergoing breast surgery under local anesthesia and sedation were studied. Simultaneous BIS and SE measurements were recorded every 10 seconds. Artifact was defined as a failure of the device to display a numerical value while the electrodes remained appropriately attached to the patient's forehead. Ratio of artifact to good signal was compared between BIS and SE in the presence or absence of EC use.
  
  
  RESULTS
  7679 data points were collected from 28 patients. Overall, artifact incidence was similar in BIS and SE (6.2% and 6.3%, resp.). In the presence of EC (1370 data points), BIS had significantly more artifact compared to SE (18.6% versus 6.4%, P < 0.0001). Without EC (6309 data points), BIS had significantly less artifact compared to SE (4.1% versus 7.3%, P < 0.0001).
  
  
  CONCLUSIONS
  BIS and SE were comparable for incidence of artifacts in patients under sedation. Use of EC lead to more artifact in BIS than SE. Conversely, BIS had fewer artifacts than SE when there was no EC use.
authors.affiliation: Department of Anesthesiology, University of Illinois at Chicago, 1740 West Taylor Street, Suite 3200W, Chicago, IL 60612, USA.
authors.forename: Chanannait
authors.initials: C
authors.lastname: Paisansathan
authors.forename: Mukadder D
authors.initials: MD
authors.lastname: Ozcan
authors.forename: Qaiser S
authors.initials: QS
authors.lastname: Khan
authors.forename: Verna L
authors.initials: VL
authors.lastname: Baughman
authors.forename: Mehmet S
authors.initials: MS
authors.lastname: Ozcan
mesh_terms: D000328:Adult; D004566:Electrodes; D019277:Entropy; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D013514:Surgical Procedures, Operative
chemical_list: D006993:Hypnotics and Sedatives