Efficacy of Ultrasound-Guided Interscalene Brachial Plexus Block for Acute Post-Hepatectomy Shoulder Pain: A Randomized Controlled Trial

Objective: To investigate the efficacy of ultrasound-guided interscalene brachial plexus block in the treatment of shoulder pain following hepatectomy. Design: A randomized controlled trial. Methods: We conducted a single-center, randomized controlled trial. Forty-four patients with shoulder pain scores of at least 5 were randomly assigned to two groups: the treatment group, which received 0.5% ropivacaine (5mL) combined with dexamethasone (5 mg) (n=22), and the control group, which received normal saline (5mL) (n=22). The intervention was performed in the postanesthesia care unit after shoulder pain was identified by using the visual analogue scale. The shoulder pain was re-evaluated 15 minutes after intervention. The incidence of effective pain relief, defined as at least 75% reduction in pain intensity, was the primary outcome. Secondary outcomes included shoulder pain intensity within 2 days after surgery, the timing of the first rescue analgesia, total additional analgesic use, arterial oxygen saturation, intervention-related adverse reactions, and patient satisfaction regarding shoulder pain. Results: The incidence of effective pain relief was significantly higher in the treatment group compared to the control group (15 (68.2%) vs 2 (9.1%), P <0.001). The interscalene brachial plexus block not only prolonged the time to first analgesic request (P P <0.001), but also reduced the number of analgesic requests (P P <0.001). In the comparison between groups, arterial oxygen saturation was lower in the control group than that in the treatment group, attributed to the use of sufentanil for remedial analgesia (92.4% vs 94.5%, P =0.014). Conclusion: Interscalene brachial plexus block can effectively relieve post-hepatectomy shoulder pain without clinically significant hypoxemia.