The Effect of Preoperative Interscalene Block Using Low-Dose Mepivacaine on the Postoperative Pain after Shoulder Arthroscopic Surgery

ABSTRACT

BACKGROUND: Shoulder arthroscopic surgery is frequently associated with severe postoperative pain, which can be difficult to manage without the use of high-dose opioids. Although an interscalene brachial plexus block (ISBPB) can be used to provide anesthesia for shoulder arthroscopic surgery, its effect using low-dose mepivacaine on postoperative pain management has not been reported. We hypothesized that ISBPB using a low-dose mepivacaine can provide effective postoperative analgesia for shoulder arthroscopic surgery without the need for high-dose opioids and act as a significant motor or sensory block. METHODS: This study examined a total of 40 patients, who underwent shoulder arthroscopic surgery, and received ISBPB with 10 ml of normal saline (group NS; n = 20) or 10 ml of 1% mepivacaine with epinephrine 1200,000 (group MC; n = 20). The block was performed preoperatively. The postoperative pain score, opioid consumption, and side effect were recorded. RESULTS: The visual analog scale scores were significantly lower in group MC than in group NS at 120 minutes after shoulder arthroscopic surgery (1.9 +/- 1.0 versus 4.0 +/- 1.4). Group MC showed significantly lower fentanyl consumption after shoulder arthroscoic surgery than group NS (27 +/- 32.6 versus 79 +/- 18.9microgram). The degree of motor and sensory block after surgery was minimal. CONCLUSIONS: ISBPB using low-dose mepivacaine reduced the level of postoperative pain and fentanyl consumption without significant side effects. ISBPB using low-dose mepivacaine is a useful analgesic technique for shoulder arthroscopic surgery.