Does addition of lidocaine to medium- and long-chain triglyceride propofol emulsions significantly reduce pain on injection?
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.


METHODS
The present study included 270 non-premedicated ASA I-II adult patients scheduledfor 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.
Department of Anesthesiology, Chaiyaphum Hospital, Chaiyaphum, Thailand. albkb@diamond.mahidol.ac.th
Banjong
B
Krobbuaban
Diregpoke
D
Siriwan
Sujarit
S
Kumkeaw
Malin
M
Tanomsat
Gaison
G
Jamjamrat
Kaewan
K
Thanetses
Surangrat
S
Kosittanasan
D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004655:Emulsions; D005260:Female; D006801:Humans; D015994:Incidence; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D010146:Pain / Q000517:prevention & control*; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D012307:Risk Factors; D014280:Triglycerides / Q000008:administration & dosage / Q000627:therapeutic use*
D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D004655:Emulsions; D014280:Triglycerides; D008012:Lidocaine; D015742:Propofol