title: Influence of dexmedetomidine on cognitive function in volunteers.
abstract: OBJECTIVE
  Some outpatient procedures are performed under sedation with dexmedetomidine, although the effect of dexmedetomidine on cognitive function remains unclear. This study investigated the effect of dexmedetomidine on cognitive function in healthy volunteers.
  
  
  METHODS
  Observation study in volunteers.
  
  
  METHODS
  University-affiliated teaching hospital.
  
  
  METHODS
  Six healthy volunteers.
  
  
  METHODS
  After infusion of a 6-μg/kg per hour loading dose of dexmedetomidine for 10 minutes, a maintenance infusion of 0.4 μg/kg per hour was administered for 4 hours.
  
  
  METHODS
  Cognitive function was evaluated before infusion (baseline) and at 2, 4, 6, and 8 hours after infusion. Cognitive function, response speed, accuracy, and consistency were measured by CogHealth. Depth of sedation was evaluated at 1-hour intervals by evaluating the Bispectral Index. Data are presented as the change from baseline.
  
  
  RESULTS
  The Bispectral Index value was significantly lower from 10 minutes to 6 hours after infusion versus the pre-infusion value. Response speed was also significantly lower at 2 hours and 4 hours after infusion (92 ± 8%, P< .0001; 93 ± 6%, P< .0001), as was consistency (96 ± 7%, P= .0009; 96 ± 5%, P= .0003). Response accuracy was unaltered by the infusion.
  
  
  CONCLUSIONS
  Dexmedetomidine slightly reduced response speed and consistency, but did not affect response accuracy. Cognitive function was restored to pre-administration values 2 hours after the infusion of dexmedetomidine was discontinued.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School Kohasu, oko-cho, Nankoku, Kochi, 783-8505, Japan. Electronic address: yatabe@kochi-u.ac.jp.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yatabe
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School Kohasu, oko-cho, Nankoku, Kochi, 783-8505, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Tamura
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School Kohasu, oko-cho, Nankoku, Kochi, 783-8505, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School Kohasu, oko-cho, Nankoku, Kochi, 783-8505, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Yokoyama
mesh_terms: D000328:Adult; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine
keywords: Cognitive function; Dexmedetomidine; Volunteer