This study states that Interscalene brachial plexus blocks are a common modality used to provide adjunctive pain relief with shoulder replacement surgery. In 2018, the Federal Drug Administration approved the use of liposomal bupivacaine (LB) for such nerve blocks. We sought to evaluate whether this formulation of bupivacaine would provide superior pain relief for shoulder replacement patients over standard bupivacaine alone. Our hypotheses were that in the LB cohort the average postoperative pain score over the first 72 hours would be significantly lower, time to block cessation would be longer, total opioid consumption would be lower, and the average patient satisfaction score regarding their pain management would be higher.

A randomized, double-blinded study was designed comparing primary shoulder replacement surgery after an interscalene block with 25 mL of 0.5% plain bupivacaine vs. 133 mg of LB with 7.5 mL of 0.5% and 7.5 mL of 0.25% plain bupivacaine. A total of 104 patients were included in the study, with an equal number in each study arm.

Reference link- https://www.jshoulderelbow.org/article/S1058-2746(20)30779-5/fulltext