Comparison of anesthesia efficacy between subclavius muscle plane block and interscalene brachial plexus block for open reduction and internal fixation of clavicle fractures: study protocol for a randomized non-inferiority clinical trial.

BACKGROUND: Interscalene brachial plexus block (ISBPB) combined with supraclavicular nerve block or superficial cervical plexus block has been reported to be a reliable, efficacious anesthesia technique for clavicle fracture surgery. However, several serious adverse events impeded the development of this technique. Herein, we propose a novel nerve block technique-the subclavius muscle plane block (SMPB) combined with supraclavicular nerve block-that selectively targets the sensory nerves innervating the surgical region of the clavicle. We hypothesize that SMPB may achieve non-inferior anesthesia efficacy for clavicle surgery compared to ISBPB when combined with supraclavicular nerve block, with fewer complications.

METHODS: This study is a prospective, single-center, randomized, controlled, non-inferiority trial. A total of 76 patients scheduled for open reduction and internal fixation of clavicle fractures will be divided into two groups at random to receive either SMPB or ISBPB, combined with supraclavicular nerve block. The primary outcome will be to compare the proportion of patients not requiring sufentanil supplementation intraoperatively between the two groups. The secondary outcomes will include the pulmonary function before and 30 min after the block, onset time of anesthesia, block-related complications, conversion rate to general anesthesia, intraoperative sufentanil supplementation, surgery duration, intraoperative hemodynamic adverse events, first onset time of pain, first time to patient-controlled bolus, postoperative sufentanil consumption, Numerical Rating Scale scores for rest and dynamic pain at 3, 6, 12, and 24 h postoperatively, motor block grade at 3, 6, 12, and 24 h postoperatively, postoperative nausea and vomiting, metoclopramide dose, nerve injury, patient satisfaction score, and surgeon satisfaction score.

DISCUSSION: This study explores the SMPB as a novel anesthetic technique for clavicle surgery. Compared to ISBPB, SMPB may offer effective anesthesia while reducing complications regarding limb immobility and phrenic nerve paralysis, thus potentially enhancing patient safety, comfort, and postoperative recovery.

TRIAL REGISTRATION: Chinese Clinical Trial Register, ChiCTR2500096952. Registered on February 10, 2025.