Effect of liposomal bupivacaine for the suprascapular nerve combined with axillary nerve block on postoperative analgesia in patients undergoing shoulder surgery: a randomized, observer-blinded trial

Abstract Background This study was conducted to explore whether liposomal bupivacaine for the suprascapular nerve combined with axillary nerve block can provide noninferior postoperative analgesia and reduced hemidiaphragmatic paralysis (HDP) versus traditional interscalene brachial plexus block in patients undergoing arthroscopic shoulder surgery. Methods Patients were divided into a suprascapular nerve and axillary nerve block group (SSANB group) and an interspinal brachial plexus block group (IBB group) via a random number table. The local anesthetic used was a mixture of 1.33% liposomal bupivacaine and 0.5% levobupivacaine hydrochloride injected in equal volume. The primary outcome measures included resting numerical rating scale (NRS) scores at 72 h after surgery and the incidence of HDP 30 min after block. Results Finally, 48 patients were included. The incidence rates of HDP in the SA and IB groups were 4% (1/25) and 78.3% (18/23), respectively, with statistical significance (P < 0.001). The motor block duration in group IB was significantly longer than that in group SA (30.57 ± 17.13 vs. 0.88 ± 4.40 h, P < 0.001). There were no significant differences in the NRS score at rest after surgery, opioid consumption, satisfaction with analgesia, sensory block duration, perioperative adverse effects, or neurological complications between the two groups (all P > 0.05). Conclusions Liposomal bupivacaine for the suprascapular nerve combined with axillary nerve block can provide long-term postoperative analgesia that is noninferior to traditional interscalene brachial plexus block and results in fewer HDP occurrences in patients undergoing arthroscopic shoulder surgery. Trial registration This study was registered at www.chictr.org.cn on June 28, 2024 (registration number: ChiCTR2400086331).