title: Evident cognitive impairments in seemingly recovered patients after midazolam-based light sedation during diagnostic endoscopy.
abstract: OBJECTIVE
  Midazolam is a widely used sedative agent during colonoscopy, with cognitive toxicity. However, the potential cognitive hazard of midazolam-based light sedation has not been sufficiently examined. We aimed to examine the cognitive safety and vulnerability profile under midazolam light sedation, with a particular focus on individual variations.
  
  
  METHODS
  We conducted a prospective case-controlled study in an academic hospital. In total, 30 patients undergoing sedative colonoscopy as part of a health check-up were recruited. Neuropsychological testing on the full cognitive spectrum was evaluated at 15 minutes and 120 minutes after low-dose midazolam administration. The modified reliable change index (RCI) was used for intrapersonal comparisons and controlling for practice effects.
  
  
  RESULTS
  Midazolam affected psychomotor speed (48%), memory (40%), learning (32%), working memory (17%), and sustained attention (11%), while sparing orientation and the fluency aspect of executive function at the acute stage. Residual memory (10%) and learning (10%) impairments at 2 hours after administration were evidenced in some patients. The three object recall and digit symbol coding tests can serve as useful screening tools.
  
  
  CONCLUSIONS
  Midazolam-based light sedation induced selective cognitive impairments and prolonged cognitive impairments occurred in patients with advanced age. A longer observation time and further screening were recommended for patients due to their at risk state.
authors.affiliation: Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Neurology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan.
authors.forename: Yen-Hsuan
authors.initials: YH
authors.lastname: Hsu
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Feng-Sheng
authors.initials: FS
authors.lastname: Lin
authors.affiliation: Division of Clinical Psychology, Master of Behavioral Science, Department of Occupational Therapy, College of Medicine, Chang-Gung University, Taoyuan, Taiwan.
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Yang
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chih-Peng
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Psychiatry and Neurology, College of Medicine, National Taiwan University Hospital, Taipei, Taiwan; Neurobiological and Cognitive Science Center, National Taiwan University, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: huams@ntu.edu.tw.
authors.forename: Mau-Sun
authors.initials: MS
authors.lastname: Hua
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: wzsun@ntu.edu.tw.
authors.forename: Wei-Zen
authors.initials: WZ
authors.lastname: Sun
mesh_terms: D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects*; D001288:Attention; D016022:Case-Control Studies; D003071:Cognition; D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects*; D007858:Learning; D008297:Male; D008570:Memory, Short-Term; D008874:Midazolam / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D013624:Taiwan
chemical_list: D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D008874:Midazolam
keywords: cognitive function; endoscopy; midazolam; reliable change index