title: The assessment of memory under total intravenous anesthesia.
abstract: OBJECTIVE
  In this study, we aimed to assess implicit and explicit memory in patients who had abdominal surgery under total intravenous anesthesia (TIVA) with propofol and remifentanil, in which anesthesia level was controlled by bispectral index (BIS) monitoring.
  
  
  METHODS
  Total intravenous anesthesia was administered to 60 adult patients, to obtain BIS levels of 40-60. Patients were randomly allocated to three groups according to tapes they listened to. Patients in the category group (CT) listened to a tape containing five animal names. Patients in the word recognition group (WM) listened to a tape containing five intermediate-frequency words, adapted into Turkish. Patients in the control group (CG) listened to sea sounds until the end of surgery. Two hours after surgery, tests were administered to each patient in the recovery room to assess memory.
  
  
  RESULTS
  There was a difference between the CT and CG groups in their Mini-Mental State Examination scores, all values were > 20. The results of the category and word recognition tests that were applied to assess implicit memory were not statistically different among the groups. There was no evidence of implicit memory in any of the patients. One patient remembered hearing 'the sound of water' as a proof of explicit memory. Eleven patients said they had dreamt.
  
  
  CONCLUSIONS
  Although no evidence of implicit memory under adequate anesthesia with TIVA was found, one patient showed explicit memory. Although adequate depth of anesthesia provided by BIS monitoring supports our implicit memory results, it does not explain the explicit memory results.
authors.affiliation: Department of Anesthesiology and Reanimation, Dokuz Eylul University Medical School, Istanbul, Turkey.
authors.forename: Gulistan
authors.initials: G
authors.lastname: Aktas
authors.forename: Elvan
authors.initials: E
authors.lastname: Sahin
authors.forename: Meltem
authors.initials: M
authors.lastname: Turkay Aydogmus
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Erkin
mesh_terms: D000328:Adult; D000768:Anesthesia, General / Q000523:psychology*; D000771:Anesthesia, Intravenous / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D011446:Prospective Studies