title: Dexmedetomidine Reduces Shivering during Mild Hypothermia in Waking Subjects.
abstract: OBJECTIVE
  Reducing body temperature can prolong tolerance to ischemic injury such as stroke or myocardial infarction, but is difficult and uncomfortable in awake patients because of shivering. We tested the efficacy and safety of the alpha-2-adrenergic agonist dexmedetomidine for suppressing shivering induced by a rapid infusion of cold intravenous fluids.
  
  
  METHODS
  Ten subjects received a rapid intravenous infusion of two liters of cold (4°C) isotonic saline on two separate test days, and we measured their core body temperature, shivering, hemodynamics and sedation for two hours. On one test day, fluid infusion was preceded by placebo infusion. On the other test day, fluid infusion was preceded by 1.0 μg/kg bolus of dexmedetomidine over 10 minutes.
  
  
  RESULTS
  All ten subjects experienced shivering on placebo days, with shivering beginning at a mean (SD) temperature of 36.6 (0.3)°C. The mean lowest temperature after placebo was 36.0 (0.3)°C (range 35.7-36.5°C). Only 3/10 subjects shivered on dexmedetomidine days, and the mean lowest temperature was 35.7 (0.4)°C (range 35.0-36.3°C). Temperature remained below 36°C for the full two hours in 6/10 subjects. After dexmedetomidine, subjects had moderate sedation and a mean 26 (13) mmHg reduction in blood pressure that resolved within 90 minutes. Heart rate declined a mean 23 (11) bpm after both placebo and dexmedetomidine. Dexmedetomidine produced no respiratory depression.
  
  
  CONCLUSIONS
  Dexmedetomidine decreases shivering in normal volunteers. This effect is associated with decreased systolic blood pressure and sedation, but no respiratory depression.
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Clifton W
authors.initials: CW
authors.lastname: Callaway
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America; Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Elmer
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Francis X
authors.initials: FX
authors.lastname: Guyette
authors.affiliation: Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Molyneaux
authors.affiliation: School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Kacey B
authors.initials: KB
authors.lastname: Anderson
authors.affiliation: School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Empey
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Stacy J
authors.initials: SJ
authors.lastname: Gerstel
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Kate
authors.initials: K
authors.lastname: Holquist
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Repine
authors.affiliation: Applied Physiology Laboratory, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors.forename: Jon C
authors.initials: JC
authors.lastname: Rittenberger
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D020927:Dexmedetomidine / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects / Q000627:therapeutic use*; D007036:Hypothermia, Induced / Q000379:methods; D008297:Male; D012768:Shivering / Q000187:drug effects*; D055815:Young Adult
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine