Bone_1999_Reg.Anesth.Pain.Med_24_405

BACKGROUND AND OBJECTIVES The acetylcholinesterase inhibitor neostigmine has shown peripherally mediated analgesic action in recent preclinical and clinical studies. The present study investigates the effectiveness of adding neostigmine to a local anesthetic, mepivacaine, in patients receiving axillary brachial plexus block for upper extremity surgery. METHODS: In a double-blind, randomized study 34 patients were assigned to the treatment group: Neostigmine (NM) (500 microg) + mepivacaine (M) (500 mg) (NM, n = 17) as drugs for the plexus block, or to control group: mepivacaine (500 mg) + saline (0.9%, 1 mL) (M, n = 17). RESULTS: The onset and duration of sensory and motor block was similar in both groups. Patients receiving NM had significantly lower pain ratings [visual analogue scores (VAS): 14.7 +/- 9.9 vs 32.4 +/-23.5; P < .05] 24 hours after surgery, and a lower number of patients in the NM group needed supplemental analgesics during the first 24 hours postoperatively. No adverse events were recorded for either group.
CONCLUSIONS: Peripherally administered neostigmine improves postoperative analgesia in axillary brachial plexus block.