title: Age-dependent relationship between bispectral index and sedation level.
abstract: OBJECTIVE
  To determine the relationship between bispectral index (BIS) and sedation.
  
  
  METHODS
  Prospective, observational clinical study.
  
  
  METHODS
  Intensive care unit of a public hospital in Japan.
  
  
  METHODS
  22 ASA physical status I, II, and III middle-aged (18-65 yrs) and elderly (>65 yrs) patients receiving postoperative sedation with midazolam.
  
  
  METHODS
  Patients were allocated to two groups: Group M was composed of middle-aged patients (<65 yrs) and Group H elderly patients (>65 yrs). Midazolam was administered at a bolus dose of 0.1 mg/kg, followed by a continuous dose of 0.04 mg/kg per hour, which was adjusted every two hours to achieve a target level of sedation at 3-6 on the Ramsay Sedation Scale (RSS); buprenorphine was administered at a constant rate (0.625 microg kg(-1) hr(-1)).
  
  
  METHODS
  BIS value, RSS, midazolam dose, body temperature (BT), heart rate, dopamine dose, and mean arterial pressure were recorded every two hours by an independent nurse. Data were analyzed using Spearman rank correlation and the Mann-Whitney U test.
  
  
  RESULTS
  BIS values decreased depending on depth of sedation; a significant correlation was noted between groups in RSS and BIS. The BIS values at levels of RSS 5 and 6 were significantly lower in Group H than Group M.
  
  
  CONCLUSIONS
  BIS correlated with sedation depth, with BIS scores in group H than group M at a deep sedation depth.
authors.affiliation: Department of Anesthesia, Nagasaki Rosai Hospital, Sasebo, Japan. kazy@plum.ocn.ne.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yamashita
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Terao
authors.forename: Chiaki
authors.initials: C
authors.lastname: Inadomi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takada
authors.forename: Makoto
authors.initials: M
authors.lastname: Fukusaki
authors.forename: Koji
authors.initials: K
authors.lastname: Sumikawa
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D016292:Procedural Sedation / Q000295:instrumentation / Q000379:methods; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives; D008297:Male; D008874:Midazolam; D008875:Middle Aged; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam