Temporary application of an additional forearm tourniquet reduces the dose of lidocaine for intravenous regional anesthesia

Abstract

Background Local anesthetic toxicity is a serious complication of intravenous regional anesthesia (IVRA). We investigated whether temporary application of an additional forearm tourniquet would permit the reduction of lidocaine dosage for IVRA without affecting the quality of the block. Patients and methods One hundred patients undergoing hand surgery under IVRA were randomized to receive ketorolac 10 mg with 40 ml of either 0.5% lidocaine (conventional group, N = 50) or 0.25% lidocaine and an additional simple forearm tourniquet applied for 5 min during and after administration of the local anesthetic (forearm group, N = 50). Results Surgical anesthesia occurred more rapidly in the forearm group (6.3 ± 1.4 vs. 8.4 ± 1.8 min in the conventional group, respectively; P P = 0.387). Time to the first analgesic requirement and the total postoperative analgesic consumption were similar in the studied groups. Significantly more patients in the conventional group experienced postoperative central nervous system manifestations than those in the forearm group (15 vs. three, respectively; P = 0.004). These manifestations were shorter lived in the forearm group (5 ± 2 vs. 16 ± 6 min, in conventional group; P < 0.0001). Conclusion Temporary application of an additional forearm tourniquet speeds the onset of IVRA and permits the use of half the dose of lidocaine, hence increasing the safety profile of the block.