Liposomal Bupivacaine Interscalene Nerve Block in Shoulder Arthroplasty

This is a prospective, single-blinded randomized clinical trial comparing outcomes in patients undergoing total shoulder arthroplasty (anatomic and reverse) who receive a peripheral nerve block with liposomal bupivacaine in combination with standard bupivacaine versus standard bupivacaine alone. Once consent is obtained, baseline characteristics will be recorded and patients will be randomized to intervention or control. Following surgery, patients will be followed until their 3-week post-operative visit. The primary outcome measure will be the mean difference in patient pain scores over the first 72 hours post-operatively between two groups. Secondary outcomes will include: (1) Total opioid consumption (as measured utilizing morphine intravenous equivalents) in first 72 hours and at 3 weeks (2) Patient perceived duration of block determined as the time patient perceives complete resolution of block (3) Patient satisfaction with pain control at 72 hours, 3 weeks post-operatively and patient reported outcome measures (SANE, SST, ASES, VR-12) at 3 weeks post-operatively.

Inclusion criteria

• All adult patients (>18 years of age)
• Patients undergoing standard or reverse total shoulder arthroplasty for the primary diagnoses of glenohumeral arthritis or cuff tear arthropathy
• Cognitively intact with the ability to give informed consent as outlined by our institutional review board.
• Patients must be capable of participating in the post-operative electronic survey and / or able to maintain a written diary of events

Exclusion criteria

• Non-elective cases
• Infection, tumor, trauma
• Weight < 50 kg
• Patients with any contraindications to regional anesthesia including allergy or hypersensitivity to amide-type local anesthetics
• Patients with allergy to any component of medication regimen e.g. amide- type local anesthetics, oxycodone, hydromorphone, fentanyl
• Chronic pain patients with history of chronic opioid use (defined as 20 mg morphine equivalent / day for greater than 30 days pre-operatively
• Concurrent painful physical condition that may require analgesic treatment that is not related to the shoulder surgery (chronic peripheral neuropathy, radiculopathy, or other neurologic disorder)
• Severe hepatic disease defined by clinical evidence of liver disease with abnormal liver function tests.
• Pregnancy
• Respiratory disease that contraindicates interscalene nerve block (elevated contralateral hemidiaphragm, contralateral pneumonectomy, or severe COPD with FEV1 < 50% predicted, and 02 dependence)