title: Lidocaine pretreatment with tourniquet versus lidocaine-propofol admixture for attenuating propofol injection pain: a randomized controlled trial.
abstract: OBJECTIVE
  Findings from studies investigating optimal techniques for attenuating propofol-related injection pain are inconsistent. In previous studies, lidocaine pretreatment using a tourniquet has been reported to be superior, inferior, or equivalent to a lidocaine-propofol admixture for reducing pain. This discordance could represent either no meaningful difference in the treatments or underlying methodological differences in the previous studies. We hypothesized that tourniquet-controlled pretreatment with lidocaine would be superior to lidocaine-propofol admixture for reducing propofol injection pain.
  
  
  METHODS
  This randomized controlled trial compared 3 groups-a control group (saline pretreatment/saline admixture; n = 50), a pretreatment group (lidocaine pretreatment/saline admixture; n = 51), and an admixture group (saline pretreatment/lidocaine admixture; n = 50). The primary outcome was verbal pain score after injection. The incidence of pain on injection was explored as a secondary outcome.
  
  
  RESULTS
  The median (interquartile range) verbal pain score after study solution injection were as follows-control group: 3 (0-6), pretreatment group: 0 (0-0), and admixture group: 0 (0-2). The pretreatment group had significantly lower pain scores when compared with the admixture group (P = 0.016), and both groups were superior to the control group. The pretreatment group had fewer subjects experiencing any injection pain than did the admixture group (20% vs. 44%, respectively; P = 0.024).
  
  
  CONCLUSIONS
  Tourniquet-controlled pretreatment with lidocaine is statistically superior to admixing lidocaine with propofol for reducing propofol injection pain intensity, but the clinical importance of this small effect is questionable. However, pretreatment more effectively eliminates injection pain.
authors: Department of Anesthesiology, Virginia Mason Medical Center, 1100 Ninth Avenue, Seattle, WA 98111, USA.
authors: Benjamin J
authors: BJ
authors: Walker
authors: Joseph M
authors: JM
authors: Neal
authors: Michael F
authors: MF
authors: Mulroy
authors: Juliette A
authors: JA
authors: Humsi
authors: Rachel C
authors: RC
authors: Bittner
authors: Susan B
authors: SB
authors: McDonald
mesh_terms: D000328:Adult; D000368:Aged; D019162:Anesthetics, Combined / Q000008:administration & dosage* / Q000009:adverse effects; D018686:Anesthetics, Intravenous / Q000008:administration & dosage* / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D015742:Propofol / Q000008:administration & dosage* / Q000009:adverse effects; D014111:Tourniquets; D016896:Treatment Outcome; D014861:Washington
chemical_list: D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008012:Lidocaine; D015742:Propofol