The optimal effective concentration of lidocaine to reduce pain on injection of propofol

J Clin Anesth. 1999 Jun;11(4):296-300. doi: 10.1016/s0952-8180(99)00040-9.


Study objective: To determine the optimal concentration of lidocaine that reduces pain on injection of a propofol-lidocaine mixture.

Design: Prospective, randomized, double-blinded, clinical investigation.

Setting: Medical center, university teaching hospital.

Patients: 240 ASA physical status I and II female outpatients, aged 21 to 65 years, undergoing dilation and curettage with propofol for anesthesia induction.

Interventions: Patients were randomized to one of four groups in double-blinded fashion. In Group A (control), patients were given propofol containing normal saline; in Group B, Group C, and Group D, patients received propofol containing 0.05% lidocaine (Group B), propofol containing 0.1% lidocaine (Group C), and propofol containing 0.2% lidocaine (Group D) for induction.

Measurements and main results: The incidence of pain on injection of propofol was significantly decreased in Group C and Group D (8.3% and 10.0%, respectively) in comparison to the control group (91.7%) (p < 0.001). Although the result in Group B (76.7%) was better than that in the control group, the difference was not statistically significant. No significant difference was seen between Group C and Group D.

Conclusions: The optimal effective concentration of lidocaine, which decreased the incidence of pain caused by propofol injection, was 0.1% in the currently studied population.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anesthetics, Intravenous / administration & dosage*
  • Anesthetics, Intravenous / adverse effects
  • Anesthetics, Local / administration & dosage*
  • Dilatation and Curettage
  • Double-Blind Method
  • Female
  • Humans
  • Incidence
  • Injections, Intravenous / adverse effects
  • Lidocaine / administration & dosage*
  • Middle Aged
  • Pain / prevention & control*
  • Propofol / administration & dosage*
  • Propofol / adverse effects
  • Prospective Studies


  • Anesthetics, Intravenous
  • Anesthetics, Local
  • Lidocaine
  • Propofol