title: Low-dose intramuscular dexmedetomidine as premedication: a randomized controlled trial.
abstract: BACKGROUND
  Dexmedetomidine-induced bradycardia or hypotension has recently attracted considerable attention because of potentially grave consequences, including sinus arrest and refractory cardiogenic shock. A route other than intravenous injection or a low dose may help minimize cardiovascular risks associated with dexmedetomidine. However, few studies have addressed the clinical effects of low-dose intramuscular dexmedetomidine as premedication.
  
  
  METHODS
  Forty American Society of Anesthesiologists physical status I adult patients undergoing suspension laryngoscopic surgery were randomized to receive intramuscular dexmedetomidine (1 µg·kg-1) or midazolam (0.02 mg·kg-1) 30 minutes prior to anaesthesia induction. The sedative, hemodynamic, and adjuvant anaesthetic effects of both premedications were assessed.
  
  
  RESULTS
  The levels of sedation (Observer's Assessment of Alertness/Sedation scales) and anxiety (visual analog score) at pre-induction, and the times to eye-opening and extubation, were not different between the groups. The heart rate response following tracheal intubation and extubation, and mean arterial pressure responses after extubation, were attenuated in the dexmedetomidine group compared to the midazolam group. No bradycardia or hypotension was noted in any patients. Propofol target concentrations at intubation and at start and completion of surgery were decreased in the dexmedetomidine group, whereas no difference in respective remifentanil levels was detected.
  
  
  CONCLUSIONS
  This study provides further evidence that dexmedetomidine premedication in low dose (1 μg·kg-1) by intramuscular route can induce preoperative sedation and adjuvant anaesthetic effects without clinically significant bradycardia or hypotension.
authors.affiliation: Department of Anaesthesiology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Yang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Anaesthesiology, Second Affiliated Hospital, Hebei Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Chaolei
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Anaesthesiology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Bin
authors.initials: B
authors.lastname: Luo
authors.affiliation: Department of Anaesthesiology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Shouzhang
authors.initials: S
authors.lastname: She
authors.affiliation: Department of Anaesthesiology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Lixin
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Anaesthesiology, Guangzhou First People's Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China (mainland).
authors.forename: Xiangcai
authors.initials: X
authors.lastname: Ruan
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D020927:Dexmedetomidine / Q000008:administration & dosage* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008874:Midazolam / Q000008:administration & dosage / Q000494:pharmacology; D008875:Middle Aged; D011292:Premedication
chemical_list: D018686:Anesthetics, Intravenous; D020927:Dexmedetomidine; D008874:Midazolam