title: The effects of intravenous dexmedetomidine on spinal anesthesia: comparision of different dose of dexmedetomidine.
abstract: BACKGROUND
  In this prospective, randomized, double-blind, placebo-controlled trial, we tried to find out appropriate amounts of single-dose dexmedetomidine to prolong the duration of spinal anesthesia in a clinical setting.
  
  
  METHODS
  Sixty patients who were scheduled for unilateral lower limb surgery under spinal anesthesia were randomized into three groups receiving normal saline (control group, n = 20) or 0.5 or 1.0 ug/kg dexmedetomidine (D-0.5 group, n = 20; D-1, n = 20) intravenously prior to spinal anesthesia with 12 mg of bupivacaine. The two-dermatome pinprick sensory regression time, duration of the motor block, Ramsay sedation score (RSS), and side effects of dexmedetomidine were assessed.
  
  
  RESULTS
  The two-dermatome pinprick sensory regression time (57.6 ± 23.2 vs 86.5 ± 24.3 vs 92.5 ± 30.7, P = 0.0002) and duration of the motor block (98.8 ± 34.1 vs 132.9 ± 43.4 vs 130.4 ± 50.4, P = 0.0261) were significantly increased in the D-0.5 and D-1 groups than in the control group. The RSS were significantly higher in the D-0.5 and D-1 groups than in the control group. However, there were no patients with oxygen desaturation in dexmedetomidine groups. The incidences of hypotension and bradycardia showed no differences among the three groups.
  
  
  CONCLUSIONS
  Both 0.5 and 1.0 ug/kg of dexmedetomidine administered as isolated boluses in the absence of maintenance infusions prolonged the duration of spinal anesthesia.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Mi Hyeon
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Jae Houn
authors.initials: JH
authors.lastname: Ko
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Mi Hwa
authors.initials: MH
authors.lastname: Cheung
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Young Ryong
authors.initials: YR
authors.lastname: Choi
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Choi
keywords: Bupivacaine; Dexmedetomidine; Spinal anesthesia