Efficacy of Liposomal Bupivacaine Infiltration on the Management of Total Knee Arthroplasty

Abstract

Importance Liposomal bupivacaine is a novel extended-duration anesthetic that has recently been used for local infiltration in total knee arthroplasty (TKA). Athough liposomal bupivacaine is widely used, it is unknown if the benefits justify the cost in the veteran population at our institution. Objective To evaluate a change in practice: the effect of local infiltration of liposomal bupivacaine on perioperative outcomes in patients undergoing primary TKA. Design, Setting, and Participants A retrospective cohort study was conducted among patients who underwent primary TKA at a Veterans Affairs Medical Center before (March 3, 2013-March 2, 2014) and after (March 3, 2014-March 2, 2015) the implementation of liposomal bupivacaine for local infiltration in TKA. Intervention Drug utilization evaluation of liposomal bupivacaine for local infiltration in TKA. Main Outcomes and Measures Use of opioids after discharge from the postanesthesia care unit. Results Among 199 patients, those who received liposomal bupivacaine after primary TKA (mean [SD] age, 65.3 [6.9] years; 93 males and 5 females) had a reduced median opioid use in the first 24 hours after surgery compared with those who did not receive liposomal bupivacaine (mean [SD] age, 64.9 [8.4] years; 95 males and 6 females; [intravenous morphine equivalents, 12.50 vs 22.50 mg; P = .001]). The use of patient-controlled analgesia was also reduced among patients who received liposomal bupivacaine vs those who did not (49 vs 91; P < .001). A reduction in the use of antiemetics was observed in the first 24 hours after surgery (13 vs 34; P = .001) and in the postanesthesia care unit among those who received liposomal bupivacaine vs those who did not (4 vs 20; P = .001). The number of patients in the postanesthesia care unit with no pain was improved among those who received liposomal bupivacaine vs those who did not (44 vs 19; P < .001). Although median (interquartile range) pain scores in the postanesthesia care unit were improved among patients who received liposomal bupivacaine vs those who did not (4.0 [0.0-6.6] vs 5.5 [3.0-7.5]; P = .001), patients who received liposomal bupivacaine had greater median (interquartile range) pain scores 48 hours (5.5 [4.0-7.0] vs 5.0 [3.0-6.0]; P = .01), 72 hours (5.0 [4.0-6.0] vs 4.0 [2.0-6.0]; P = .002), and 96 hours (5.0 [3.0-6.5] vs 4.0 [1.0-5.0]; P = .003) after surgery than those who did not receive liposomal bupivacaine. There was no difference in the median length of stay between the 2 groups. Institutional cost savings was estimated at $27 000 per year. Conclusions and Relevance Local infiltration of liposomal bupivacaine reduces use of opioids in the first 24 hours after primary TKA. Similarly, reduction in antiemetic use and improved postoperative pain are also seen in the first 24 hours after surgery but are limited to this time frame. Furthermore, a positive institutional cost savings was observed.