title: Dexmedetomidine combined with midazolam vs. dexmedetomidine alone for sedation during spinal anesthesia.
abstract: BACKGROUND
  Dexmedetomidine is a useful sedative agent for spinal anesthesia. However, it has been reported that dexmedetomidine decreases heart rate in a dose-dependent manner. In the current study, we compared the administration of a bolus dose of midazolam and bolus loading of dexmedetomidine over 10 min with the goal of identifying an additional method of sedation.
  
  
  METHODS
  Ninety patients classified as American Society of Anesthesiologists physical status I-II who were undergoing spinal anesthesia were divided into two groups. In the midazolam and dexmedetomidine combined group (group MD), 10 min after bolus loading of 0.05 mg/kg midazolam, 0.5 µg/kg/h dexmedetomidine was continuously infused. In the dexmedetomidine group (group D), 1 µg/kg dexmedetomidine was infused over 10 min, and then 0.5 µg/kg/h dexmedetomidine was continuously infused.
  
  
  RESULTS
  At 10 min, the sedation depth of the two groups was almost equal. In both groups, the bispectral index was within the optimal score range of 55-80 and the Ramsay Sedation Scale score was within the optimal range of 3-5. Satisfaction with sedation for both patient and surgeon did not differ between the two groups. At 10 min, heart rate was significantly lower (P < 0.010) in group D and mean blood pressure was significantly lower (P < 0.010) in group MD. The prevalence of bradycardia, hypotension, and hypoxia did not differ statistically between the two groups (P = 0.714, P = 0.089, P = 0.495, respectively).
  
  
  CONCLUSIONS
  Midazolam bolus and dexmedetomidine continuous infusion (the regimen of group MD) may be an additional sedation method for patients who have severe bradycardia.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Douk-Keun
authors.initials: DK
authors.lastname: Yoon
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Jong-Seouk
authors.initials: JS
authors.lastname: Ban
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Sang-Gon
authors.initials: SG
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Ji-Hyang
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Eunju
authors.identifier: 0000-0002-7299-4644
authors.initials: E
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Daegu Fatima Hospital, Daegu, Korea.
authors.forename: Jihyun
authors.identifier: 0000-0002-5373-3887
authors.initials: J
authors.lastname: An
keywords: Dexmedetomidine; Midazolam; Spinal anesthesia