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.

Efficacy of lidocaine on preventing incidence and severity of pain associated with propofol using in pediatric patients

“…However, the potential mechanism of the injection pain associated with the using of propofol was still unclear. The insolubility and the application of emulsion was once thought to be the culprit of the injection pain, thus, the alteration in concentration, [29] infusion rate, [30] and the research about the water-soluble propofol prodrugs [31] had been considered by clinical scientists. Actually, it should be admitted that the pharmacological interventions played an important role in reducing the propofol injection pain in current clinical anesthesia.…”

Prevention of propofol-induced pain in children: pretreatment with small doses of ketamine

“…Physical and pharmacological approaches have been proposed to reduce propofol injection pain. These attempts include pretreatment or premixture of propofol with lidocaine [4,9], ketamine [3,4], thiopental sodium [10], N 2 O [11], opioid [12] , cooling [13], diluting the propofol solution [14], or changing the propofol formulation [15]. However, none of these strategies is very effective in eliminating the pain completely.…”

Pain on propofol injection: Causes and remedies

“…Dilution of propofol to 0.5% in MCT/LCT produced less pain in children between 2 and 6 years, but there was an increase in triglyceride levels in blood. [8]…”