title: Propofol-sodium thiopental admixture reduces pain on injection.
abstract: BACKGROUND
  Propofol injection associated with a high incidence of pain is well known. Propofol and sodium thiopental mixture has recently been reported to be used for cost saving and able to reduce pain on injection.
  
  
  METHODS
  This prospective, randomized, double blind trial was designed to compare the efficacy of different percentages of propofol and sodium thiopental mixture in minimizing propofol injection pain. 146 ASA class 1 patients were assigned to seven groups (pure propofol, pure sodium thiopental, and propofol premixed with 10%, 20%, 30%, 40%, and 50% of sodium thiopental). The intensity of pain was graded and recorded as severe, moderate, mild and no pain according to the response of the patients to the injection.
  
  
  RESULTS
  The intensity of injection pain was significantly greater for pure propofol than the others while it was not significantly different among the other groups in comparison.
  
  
  CONCLUSIONS
  Sodium thiopental, when added to propofol, can significantly reduce propofol injection pain. This attenuation effect was noted even with as low as 10 volume % of sodium thiopental.
authors.affiliation: Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou, Taoyuan, R.O.C.
authors.forename: Y C
authors.initials: YC
authors.lastname: Kau
authors.forename: R S
authors.initials: RS
authors.lastname: Wu
authors.forename: K S
authors.initials: KS
authors.lastname: Cheng
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D013874:Thiopental / Q000008:administration & dosage*
chemical_list: D018686:Anesthetics, Intravenous; D013874:Thiopental; D015742:Propofol