Infraclavicular plexus block: Multiple injection versus single injection

Background and Objectives: This prospective, randomized, and multicentered study was undertaken to evaluate the success rate of coracoid infraclavicular nerve block performed with a nerve stimulator when either 1 or 3 motor responses were sought. Methods: Eighty patients who presented for elbow, forearm, or wrist surgery were randomly allocated to one of the following groups: in group I (single stimulation), 30 ml, local anesthetic (LA) was injected after locating only 1 of the median, ulnar, or radial motor responses. In group 2 (multistimulation), 3 responses were located: musculocutaneous, median or ulnar, and radial response, corresponding, respectively, to the lateral, medial, and posterior cords. A total of 10 mL LA was injected on each response. Bupivacaine 0.5% and lidocaine 2% with epinephrine 1:200,000 (1:1 vol) were used as the LA mixture. Sensory and motor blocks were tested by a blinded observer. Results: Block duration was slightly increased in the multistimulation group (P = .004). The onset time of sensory and motor block was faster in each nerve distribution, particularly in the radial, musculocutaneous, and antebrachial nerves. The success of anesthesia increased in the multistimulation group. The success rate of the block, without any additional block, sedation, or general anesthesia, increased from 40% in the single stimulation group to 72.5% in the multistimulation group (P < .0001). If the brachial and antebrachial cutaneous nerves were not included in the evaluation, success rate reached 87.5%. Conclusion: We conclude that by performing an infraclavicular block with stimulation of all 3 cords of the brachial plexus, the success rate is higher than when only a single stimulation is used.