Do local liposomal bupivacaine and interscalene nerve block provide similar pain control after shoulder arthroplasty? A dual-center randomized controlled trial

Background: Interscalene nerve block (INB) has become a popular technique for shoulder anesthesia. However, INB is associated with complication rates as high as 20%. Local liposomal bupivacaine (LLB) is an alternative to INB that potentially offers extended pain control with fewer adverse effects. Methods: We conducted a dual-center randomized controlled trial of 108 participants who were treated with LLB (n = 54) or INB (n = 54) to control pain after shoulder arthroplasty. We assessed visual analog scale pain scores at 6-hour intervals from 6 to 96 hours postoperatively and at the first postoperative visit. We assessed opioid medication consumption intraoperatively and on days 1, 2, 3, and 4 postoperatively, as well as the duration of hospital and postanesthesia care unit (PACU) stays. Results: At 6 hours postoperatively, the mean visual analog scale pain score was lower in the INB group (2.9 ± 3.1) than in the LLB group (5.1 ± 2.9, P < .01). The INB group consumed less opioid medication during the first 24 hours postoperatively (18 ± 12 morphine milligram equivalents) than did the LLB group (36 ± 48 morphine milligram equivalents, P = .01). The PACU stay was shorter in the INB group (102 ± 53 minutes) compared with the LLB group (139 ± 77 minutes, P < .01). Conclusions: Compared with LLB, INB provides better pain control immediately after shoulder arthroplasty as evidenced by shorter PACU stays, lower pain scores at 6 hours postoperatively, and less opioid medication consumption during the first 24 hours postoperatively. However, no differences in outcomes were observed between groups beyond 24 hours.