title: Effect of a 0.5% dilution of propofol on pain on injection during induction of anesthesia in children.
abstract: BACKGROUND
  Pain on injection of propofol in children has been reported to be as high as 30-80%. The reason for the pain is assumed to be the aqueous phase of the propofol emulsion. Therefore, for the first time, this study tested the hypothesis that dilution of propofol to a 0.5% emulsion might reduce the incidence of pain during propofol injection.
  
  
  METHODS
  The study design was prospective, monocenter, double-blind, and randomized. Sixty-four children aged 2-6 yr were scheduled to receive 0.5% or 1.0% propofol in a medium-chain-triglyceride/long-chain-triglyceride emulsion. Incidence and intensity of pain were assessed by spontaneous expressions of pain and withdrawal of the arm. In a subgroup of 21 children, serum triglyceride levels were measured before and 3 and 20 min after induction. Adverse events were recorded.
  
  
  RESULTS
  Amounts of propofol required until loss of eyelash reflex were 4.40+/-1.01 mg/kg for 0.5% propofol and 4.31+/-0.86 mg/kg for 1.0% propofol. Percentages of children who showed at least one pain reaction were 23.3% in the 0.5% propofol group and 70.0% in the 1.0% propofol group (P<0.001). Serum triglycerides were higher in the 0.5% propofol group 3 and 20 min after injection (251.7 vs. 148.8 mg/dl; P=0.001 and 135.5 vs. 75.5 mg/dl; P=0.03). Adverse events or complications did not occur.
  
  
  CONCLUSIONS
  Dilution of propofol to a 0.5% medium-chain-triglyceride/long-chain-triglyceride emulsion reduced pain effectively during injection in children aged 2-6 yr. Cumulative doses until 4-5 mg/kg propofol led to moderate increases of triglyceride levels and did not result in significant adverse events.
authors.affiliation: Department of Anesthesia and Intensive Care Medicine, Hospital Leverkusen, and University of Rostock, Rostock, Germany. soltesz@klinikum-lev.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Soltész
authors.forename: Malte
authors.initials: M
authors.lastname: Silomon
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gräf
authors.forename: Thomas
authors.initials: T
authors.lastname: Mencke
authors.forename: Sabiha
authors.initials: S
authors.lastname: Boulaadass
authors.forename: Gerd P
authors.initials: GP
authors.lastname: Molter
mesh_terms: D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D004655:Emulsions; D005260:Female; D006801:Humans; D007267:Injections / Q000009:adverse effects*; D008297:Male; D010146:Pain / Q000517:prevention & control*; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D014280:Triglycerides / Q000008:administration & dosage
chemical_list: D004655:Emulsions; D014280:Triglycerides; D015742:Propofol