Comparison of the analgesic efficacy between the ultrasound-guided continuous costoclavicular brachial plexus block and ultrasound-guided continuous interscalene brachial plexus block: a randomized controlled non-inferiority trial

The continuous interscalene brachial plexus block (ISB) is widely used for regional anesthesia in shoulder surgeries. Although the continuous costoclavicular brachial plexus block (CCB) has been proposed, its comparative efficacy and safety remain unclear. This randomized, single-blind trial aimed to determine whether the CCB offers non-inferior postoperative analgesia compared to the ISB while mitigating hemidiaphragmatic paresis (HDP). patients underwent rotator cuff repair received continuous ISB or CCB followed by 0.2% ropivacaine infusion postoperatively. The primary outcome was the resting numerical rating scale (NRS) pain score 24 h postoperatively. Secondary outcomes included block-related parameters, dynamic and resting pain scores, HDP incidence, opioid consumption, rescue analgesia requirements, and satisfaction scores. Resting NRS scores at 24 h demonstrated the non-inferiority of the CCB compared to the ISB (2.41 ± 0.59 vs. 2.00 ± 0.81; mean difference: 0.41; 95% CI: 0.1-0.73). The CCB significantly reduced the incidence of early complete HDP (30 min post-block: 7.3% vs. 41.5%; P < 0.001), with no incidence of complete HDP at 24 h. The CCB had longer block times (19.2 ± 3.7 vs. 17.2 ± 3.6 min; P = 0.013) and sensory onet (24.0 [21.0-24.0] vs. 18.0 [18.0-21.0] min; P < 0.001). Total ropivacaine consumption, rescue analgesia, or satisfaction scores were comparable. The continuous CCB is non-inferior to the ISB in terms of postoperative analgesia after rotator cuff repair and substantially decreases the risk of HDP. These findings support the CCB as a clinically advantageous alternative for shoulder surgery analgesia.