title: Which one is more efficient on propofol 2% injection pain? Magnesium sulfate or ondansetron: A randomized clinical trial.
abstract: BACKGROUND
  Painful sensation has been reported after propofol injection in most of the patients but no definite mechanism for this painful sensation has been proposed yet. The present randomized clinical trial compares analgesic effect of ondansetron, magnesium sulphate (MS) and placebo on patients after propofol 2% injection.
  
  
  METHODS
  The present randomized clinical trial with parallel design was performed on 90 patients American Society of Anesthesiologists I-II undergoing general anesthesia within vitrectomy operation with propofol induction. Subjects were randomly allocated into three groups with 30 patients each: (1) MS group (2) ondansetron group and (3) normal saline (NS) group as placebo group. Anesthesia induction and maintenance were the same between groups. Pain intensity of propofol injection in subjects was assessed by a four-point scale (none 0, mild 1, moderate 2 and severe 3) at four time intervals (5, 10, 20 and 25 s) after injection.
  
  
  RESULTS
  MS and ondansetron had significant impacts on pain reduction after propofol 2% injection in comparison with NS as placebo. Comparing two trial groups did not have any significant priority for analgesic impact.
  
  
  CONCLUSIONS
  Using ondansetron or MS had no priority on each other on declining propofol injection induced pain.
authors: Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran.
authors: Poupak
authors: P
authors: Rahimzadeh
authors: Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran.
authors: Seyed Hamid Reza
authors: SH
authors: Faiz
authors: Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran.
authors: Nasim
authors: N
authors: Nikoobakht
authors: Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran.
authors: Mohammad Reza
authors: MR
authors: Ghodrati
keywords: Magnesium sulfate; ondansetron; pain; propofol