Effective Pain Management During Shoulder Replacement Surgery With Either Continuous Ropivacaine Interscalene Nerve Block or Local Infiltration With EXPAREL After Single Shot Injection Ropivacaine Interscalene Nerve Block

Shoulder replacement surgery is recognized as having the potential to cause a considerable amount of pain that may require opioid consumption for several days post-operatively. The side effects of opioids are numerous, and ropivacaine administered pre-operatively via interscalene nerve block, with a post-operative continuous ropivacaine infusion through an indwelling catheter (CINB) is a highly effective method for controlling pain and reducing opioid consumption and side effects. While CINB provides adequate post-operative analgesia, and may extend post-operative pain relief for up to 48 hours, there are some risks associated with CINB ranging from catheter tip withdrawal to more serious complications including catheter tip beakage, brachial plexus injury, and pulmonary complications. Local infiltration of liposomal bupivacaine (EXPAREL Pacira Pharmaceuticals, Inc., Parsippany, New Jersey) may provide longer-lasting pain relief when compared to single shot INB (SSINB), and reduce opioid consumption at 24 hours, 48 hours and 72 hours post-op. Studies have shown inconsistency in the effectiveness of EXPAREL, and one proposed reason is the method of administration. Clinicians experienced in their infiltration technique demonstrated greater improvement in pain-related outcomes. The first 48 hours post-op present the most likely opportunity for reducing narcotic administration, which increases the value of attempting to reduce opioid consumption during this period. The cost of EXPAREL LIA, is slightly less than the cost of CINB, and if pain control is comparable, may benefit the patient in reducing hospital costs. The purpose of this study is to examine the effectiveness of pain control of local infiltration of EXPAREL administration to ropivacaine administered via continuous interscalene nerve block (CINB) for postoperative pain relief following shoulder replacement. Effectiveness will be measured in opioid consumption and NRS pain intensity scores from 0-4h, 4-8h, 9-12h, 13-16h, 17-20, 21-24h, 48 hours and 72 hours post-op. Patient satisfaction with pain control; patient functional outcome; adverse events related to CINB, EXPAREL administration, and opioid consumption; and pain intensity scores from the time of surgery until post-operative day 10 (+/- 5 days) will also be examined.