Superior Trunk Block Catheter Versus Single-shot Superior Trunk Block With Intravenous Dexmedetomidine for Shoulder Arthroplasty

During surgery, dexmedetomidine will be administered. After intravenous administration of 2 mcg/kg for 30 minutes, 0.5 mcg/kg/hr will be administered until the end of surgery. After surgery, a single-shot superior trunk block will be performed under ultrasound guidance. 15 mL of 0.5% ropivacaine with 1:200,000 epinephrine will be administered.

During surgery, an equivalent volume of the placebo solution was administered in a similar manner as dexmedetomidine. The superior trunk block catheter will be inserted under ultrasound guidance using 15 mL of 0.5% ropivacaine after the operation and utilize patient-controlled analgesia infusion pump with a 300 mL reservoir of ropivacaine 0.2%, and programmed the pump to deliver 5 mL per hour with an optional patient-controlled analgesia bolus of 4 mL at 30-minute lockout intervals. Patients were typically discharged home on POD 1, and block was continued until reservoir completion.