title: A randomised controlled trial of dexmedetomidine for suspension laryngoscopy.
abstract: We randomly allocated 80 patients to intravenous dexmedetomidine (0.25, 0.5, or 1 μg.kg(-1) ) or placebo 15 min before anaesthetic induction. Dexmedetomidine 0.5 and 1.0 μg.kg(-1)  significantly reduced the mean (95% CI) propofol effect-site concentrations by 0.83 (0.63-1.03) μg.ml(-1) , p = 0.001 and 1.29 (1.12-1.46) μg.ml(-1) , p = 0.0003 at intubation, by 1.05 (0.85-1.25 μg.ml(-1) , p = 0.0006 and 1.33 (1.15-1.51) μg.ml(-1) , p = 0.0002 when surgery started, and by 0.59 (0.39-0.79) μg.ml(-1) , p = 0.030 and 0.72 (0.57-0.87) μg.ml(-1) , p = 0.004 on completion of surgery, respectively. Patients' tracheas were extubated sooner after 0.5 and 1.0 μg.kg(-1)  dexmedetomidine, by 5.36 (2.39-8.32) min, p = 0.009 and 7.37 (3.24-11.51) min p = 0.003, respectively. Tachycardic responses to intubation were present in five placebo patients and no dexmedetomidine patients. Bradycardia was treated after dexmedetomidine in six patients: five after 1.0 μg.kg(-1) ; and one after 0.25 μg.kg(-1) . Single-dose dexmedetomidine can reduce anaesthetic requirements, with both desirable and undesirable haemodynamic effects.
authors.affiliation: Department of Anesthesiology, First Municipal People's Hospital of Guangzhou, Affilliated Hospital of Guangzhou Medical College, Guangzhou, China.
authors.forename: C
authors.initials: C
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: She
authors.forename: L
authors.initials: L
authors.lastname: Xu
authors.forename: X
authors.initials: X
authors.lastname: Ruan
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000758:Anesthesia; D000768:Anesthesia, General; D000771:Anesthesia, Intravenous; D001919:Bradycardia / Q000453:epidemiology; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects; D007262:Infusions, Intravenous; D007828:Laryngoscopy / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009407:Nerve Block; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use; D015742:Propofol; D000077208:Remifentanil; D018401:Sample Size; D013610:Tachycardia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D010880:Piperidines; D020927:Dexmedetomidine; D000077208:Remifentanil; D015742:Propofol