Patients who received interscalene brachial plexus block plus soft tissue infiltration with Exparel when undergoing primary shoulder arthroplasty used significantly more narcotics postoperatively and had no significant reduction in pain scores in the early postoperative period compared with patients who received interscalene brachial plexus block alone, according to results published in The Journal of Bone and Joint Surgery.
“If your hospital already has a protocol where you use interscalene nerve blocks as a form of pain management after shoulder arthroplasty, then there is no value in adding liposomal bupivacaine injection during surgery to that strategy,” Surena Namdari, MD, MSc, of Rothman Orthopaedic Institute and co-author of the study, told Healio.com/Orthopedics.
Namdari and his colleagues randomly assigned 78 patients undergoing primary shoulder arthroplasty to receive an interscalene brachial plexus block either alone (n=39) or with Exparel (bupivacaine liposome injectable suspension, Pacira Pharmaceuticals Inc.). Morphine equivalent units consumed over the first 24 hours after surgery was the primary outcome variable used. Intraoperative narcotic administration and VAS scale for pain were the secondary outcomes.
Results showed the interscalene brachial plexus block alone and interscalene brachial plexus block plus bupivacaine liposome injectable suspension groups had no significant demographic differences. When reviewing results during the first 24 hours after surgery, results showed patients who received interscalene brachial plexus block plus bupivacaine liposome injectable suspension used more narcotics than patients who received interscalene brachial plexus block alone.
“The second key finding is that, if you look at their pain scores over the first 72 hours after surgery, they were no different,” Namdari said. “Both groups had the same pain scores, but one group used more narcotics. It is likely because they are using more narcotics to get to that same pain score.”
According to Namdari, the negative effect seen when bupivacaine liposome injection suspension was added to the blocks was surprising.
“Because the liposomal bupivacaine theoretically can last for 24 to 72 hours, we thought that we would see less narcotic utilization in that group, but we saw the opposite,” he said.
Consider other strategies
Since this study focused on the use of bupivacaine liposomal injectable suspension in shoulder replacement, Namdari noted the results are not applicable to other types of surgery.
Researchers should investigate some pain management strategies that are associated with better results after shoulder replacement, such as using an interscalene catheter, he said.
“One potential role which has recently obtained FDA approval is to use the liposomal bupivacaine as the medication that is being placed into the interscalene nerve block,” Namdari said. “It will be interesting to see whether using it in that manner will have a more beneficial impact.” – by Casey Tingle
Namdari S, et al. J Bone Joint Surg Am. 2018;doi:10.2106/JBJS.17.01416.
Surena Namdari, MD, MSc, can be reached at 925 Chestnut St., 5th Fl., Philadelphia, PA 19107; email: firstname.lastname@example.org.
Disclosure: Namdari reports he receives research funding from DePuy Synthes, Zimmer Biomet, Arthrex, Tornier and Integra Life Sciences; is a paid consultant for Don Joy Orthopaedics, Miami Device Solutions and DePuy Synthes; and receives royalties from Don Joy Orthopaedics, Miami Device Solutions and Elsevier.