Liposomal bupivacaine interscalene blocks demonstrate a greater proportion of total shoulder arthroplasty patients with clinically tolerable pain: a retrospective quality improvement study of 491 patients

Abstract

Objective: To evaluate the effects of liposomal bupivacaine use for interscalene blocks on postoperative analgesia in total shoulder arthroplasty patients.

Methods: De-identified total or reverse total shoulder arthroplasty patients between 2018 and 2021 were analyzed. Patients were grouped into single shot interscalene block with liposomal bupivacaine (LB) with plain bupivacaine, other block (OB) with other local anesthetics (mepivacaine, ropivacaine, or plain bupivacaine), or no block (NB). The primary outcome was the proportion of patients with clinically tolerable pain scores (mean VAS ≤4) from 0 to 24 ​h in each group. Secondary outcomes included averaged visual analog pain scores (VAS) and opioid consumption measured in morphine milligram equivalents (MMEs) from 0 to 24 ​h. We also analyzed the proportion of patients with clinically tolerable pain, mean VAS, and opioid consumption from 0 to 72 ​h in those patients with at least a 3-day hospital length of stay.

Results: A total of 491 de-identified total shoulder arthroplasty patients, 285 liposomal bupivacaine group (LB), 178 other block group (OB), and 28 no block group (NB), were analyzed. The primary outcome showed a statistically significant different proportion of patients with clinically tolerable pain from 0 to 24 ​h in the LB group (69 ​%) vs. OB group (39 ​%) vs. NB group (11 ​%) (<0.001). Secondary outcomes included statistically significant differences in VAS (LB median ​= ​3.35, OB median ​= ​4.38, NB median ​= ​5.25 (p ​< ​0.001, <0.001)) and total MME opioid consumption (LB median ​= ​40, OB median ​= ​60, NB median ​= ​88 (p ​< ​0.001, 0.001)) between groups from 0 to 24 ​h. For patients who had hospital stays of at least 3 days, a significant association was found with having achieved clinically tolerable pain 0-72 ​h and the LB group (51 ​%) vs. OB group (21 ​%) vs. NB group (11 ​%) (P ​= ​0.006). However, there was no statistical difference in mean VAS or opioid consumption between these groups.

Conclusion: A greater proportion of total shoulder arthroplasty patients that received liposomal bupivacaine in interscalene block have clinically tolerable pain scores from 0 to 24 ​h, lower VAS, and lower MME consumption in patients following total shoulder arthroplasty.

Level of evidence: Level III - Clinical Study.

Keywords: Liposomal bupivacaine; Pain; Regional anesthesia; Total shoulder arthroplasty.