Lidocaine priming reduces tourniquet pain during intravenous regional anesthesia: A preliminary study

Tourniquet pain often limits the use of intravenous regional anesthesia (IVRA). Intravenous (IV) lidocaine has been shown to be effective in the management of acute and neuropathic pains. We tested the hypothesis that a priming IV injection of lidocaine might have an analgesic effect on tourniquet pain during IVRA.

A prospective, randomized, double- blind study was conducted on 40 patients scheduled for carpal tunnel decompression. No sedation was given. Each patient received either 1 mg/kg of IV lidocaine (group L) or 0.1 mL/kg of IV isotonic saline (group control = C) 5 minutes before IVRA. Thereafter, they received 3 mg/kg of plain 0.5 % lidocaine into the isolated and exsanguinated arm. A double-cuffed tourniquet was used. Pain at the tourniquet and the surgical sites was assessed every 5 minutes using a linear visual analog scale (VAS) and a verbal rating scale (VRS) during the surgical procedure and the immediate postoperative period (60 minutes).

Demographic data and duration of proximal and distal tourniquet were similar in each group. Significant differences in the pain scales were observed for the distal tourniquet at tourniquet inflation time and 15 minutes after (P =.03 and.005, respectively) in the group L. For the proximal tourniquet, only the VRS was significantly improved (P =.03). No analgesic benefit was observed in the immediate postoperative period.

Priming IV lidocaine when compared with isotonic saline is effective in reducing tourniquet pain in IVRA.