Buprenorphine, Clonidine, Dexamethasone, and Ropivacaine for Interscalene Nerve Blockade: A Prospective, Randomized, Blinded, Ropivacaine Dose-Response Study

80 patients undergoing total shoulder arthroplasty (TSA) were randomized into one of the four groups for postoperative analgesia. Patients were allocated with either low-dose ropivacaine (0.1%), medium-dose ropivacaine (0.2%), or high-dose ropivacaine (0.375%) interscalene nerve block (ISB) plus perineural clonidine, dexamethasone, buprenorphine, or a control group with ISB with 0.375% ropivacaine and intravenous clonidine, dexamethasone, buprenorphine. Findings indicated that 0.375% or 0.2% ropivicaine plus perineural clonidine, dexamethasone, and buprenorphine demonstrated benefits regarding pain scores, as well as an opioid-sparing effect in the case of the high-dose group, compared to the control group. Low dose ISB of 0.1% ropivacaine with perineural additives is recommended to minimize motor blockade.