Does Addition of Lidocaine to Medium- and Long-Chain Triglyceride Propofol Emulsions Significantly Reduce Pain on Injection?
Banjong Krobbuaban MD*, Siriwan Diregpoke BN*, Sujarit Kumkeaw BN*, Malin Tanomsat BN*, Gaison Jamjamrat BN*, Kaewan Thanetses BN*, Surangrat Kosittanasan BN*
Affiliation : * Department of Anesthesiology, Chaiyaphum Hospital, Chaiyaphum
Background : Propofol formulated with medium- and long-chain triglycerides (MCT/LCT) causes less pain on
injection than standard Propofol, but the incidence of pain persists between 28 and 67 percent. Such a broad
range begs the question so the authors wanted to clarify whether the addition of lidocaine to medium- and
long-chain triglyceride emulsion propofol results in any clinically significant lessening of pain on injection.
The authors conducted a randomized, prospective, double-blinded study to compare the injection pain felt
following the administration of propofol-MCT/LCT (Propofol-®Lipuro) to propofol-MCT/LCT plus 20 mg
lidocaine for the induction of anesthesia.
Material and Method: The present study included 270 non-premedicated ASA I-II adult patients scheduled for
elective surgery under general anesthesia. Patients were allocated randomly into two groups to receive either
propofol-MCT/LCT alone or propofol-MCT/LCT plus 20 mg lidocaine. The study solution was injected at 1
mL/second by one anesthesiologist and patients graded any associated pain using a four-point scale.
Results : The overall incidence of pain on injection was 31/133 (23%) in the propofol-MCT/LCT plus lidocaine
group vs. 45/135 (33%) in the propofol-MCT/LCT alone group. The difference in the incidence of pain on
injection between groups failed to achieve statistical significance (p = 0.23) and no significant difference in
intensity of pain between the two study groups occurred.
Conclusions: The authors concluded that the addition of lidocaine (20 mg) to the propofol-MCT/LCT does
not significantly reduce the incidence or severity of the pain on injection.
Keywords : Anesthesia, Pain on injection, Propofol
