Single-Injection Bupivacaine HCl Plus Either Single-Injection Liposomal Bupivacaine Interscalene Nerve Block or a Continuous Interscalene Nerve Block For Major Shoulder Arthroscopy

Once potential candidates are identified, charts will be reviewed for initial data collection and to determine if the patient meets inclusion criteria and is free of exclusion criteria. Eligible individuals will be approached in clinic or will be called one to four days before their scheduled procedure and introduced to the study. They will have the opportunity to have the consent and HIPPA forms emailed to them to review before making the decision to participate in the study.

After consent, subjects will be randomized and enrolled into the study. Subjects will be randomized into one of two arms: 1) Single-injection bupivacaine HCl plus a subsequent bupivacaine CISB, 2) Single-injection bupivacaine HCl plus liposomal bupivacaine included in the same injection. Subjects in the first arm will undergo catheter placement with ultrasound guidance by a regional anesthesiologist on the study team. A 20 mL single bolus ISB with 0.25% bupivacaine will be administered followed by catheter infusion of 0.125% bupivacaine at a rate of 5 mL/hour postoperatively by the elastomeric pump. Subjects in the second arm will be given a single injection Liposomal Bupivacaine ISB in the preoperative area by a regional anesthesiologist on the study team. The injectate will include liposomal bupivacaine 10 mL (133 mg) mixed with bupivacaine HCl 0.5% 10 mL.

Both groups will receive a standardized analgesic regimen which will include the following: preoperative acetaminophen 15mg/kg up to 1gm PO and gabapentin 600 mg PO; intraoperative dexamethasone 8mg IV, fentanyl 100 - 250 mcg IV, ketamine 30 -50mg IV, and ketorolac 0.5mg/kg up to 30mg IV at conclusion of surgery; fentanyl IV in PACU as necessary; postoperative regimen will include acetaminophen 15mg/kg up to 1gm PO q8hrs, ibuprofen 400 mg Q8 hrs and tramadol 50 mg q4hrs prn. For continued breakthrough postoperative pain unrelieved adequately by tramadol a patient may receive oxycodone 5mg PO every 4 hours as needed.

Subjects in both groups will receive baseline ASES Shoulder Score assessments before the block and procedure, and again in postoperative days 1-7. Additionally, a daily MBPI Short Form will be adminstered for the seven days post operation. The primary endpoint is to assess the median pain score on POD 1 using the MBPI Short form. Secondary endpoints include Cumulative Area Under Curve (AUC) median pain score on POD1-3, opioid consumption through POD3, satisfaction with pain treatment, block duration, success rate, amount of analgesia/sedation used for it; and adverse effects attributed to either the block or catheter, and functionality of the surgical arm.