Determination of the Optimal Volume of 0.5% Bupivacaine Liposome in Single-Injection Interscalene Brachial Plexus Block: A Bayesian Phase I/II Trial

Determination of the Optimal Volume of 0.5% Bupivacaine Liposome in Single-Injection Interscalene Brachial Plexus Block: A Bayesian Phase I/II Trial

This single-center, prospective, single-arm, Bayesian phase I/II clinical trial evaluates the incidence of HDP following ISB in shoulder arthroscopy and determines the optimal volume of a single injection of liposomal bupivacaine.

Based on the ISB being the optimal nerve block for post-arthroscopic shoulder surgery analgesia and the potent analgesic effect of bupivacaine liposomes, this study aims to explore the optimal volume of a single ISB injection of bupivacaine liposomes in shoulder arthroscopy using the Bayesian Optimal Interval Design, with the goal of achieving the same analgesic effect while minimizing the incidence and duration of HDP to the greatest extent.

Inclusion Criteria:

• Patients aged 18 years and above;
• ASA classification I-III;
• Undergoing arthroscopic rotator cuff repair, capsular tightening, acromioplasty, synovectomy,.

Exclusion Criteria:

• History of pulmonary disease;
• Abnormal coagulation function or coagulation disorders;
• History of local anesthetic allergy;
• Infection, lesion, or history of cervical disease at the block site;
• Pregnancy;
• Refusal to participate in the study or inability to communicate;
• Long-term use of opioids;
• Body mass index >35 kg/m2;
• History of nerve injury, paralysis, or paresis.