Comparison of Liposomal Bupivacaine and Conventional Local Anesthetic Agents in Regional Anesthesia: A Systematic Review.

BACKGROUND Pain is one of the most common adverse events after surgery. Regional anesthesia techniques are effective for pain control but have limited duration of action. Liposomal bupivacaine is a long-acting formulation of bupivacaine. We conduct this systematic review to assess whether liposomal bupivacaine may prolong the analgesic duration of regional anesthesia compared to conventional local anesthetic agents. METHODS We systematically searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Google Scholar, Web of Science citation index, US clinical trials register, and recent conference abstracts for relevant studies. RESULTS We identified 13 randomized controlled trials that compared the use of liposomal bupivacaine to conventional local anesthetics in regional anesthesia. There were 5 studies on transversus abdominis plane (TAP) block, 3 of which reported longer duration of analgesia with liposomal bupivacaine. One study reported comparable analgesia with liposomal bupivacaine TAP block compared to TAP block catheter. There were 3 studies on brachial plexus block, 2 of which reported that liposomal bupivacaine may provide longer analgesia. Studies on other techniques did not report significantly longer analgesia with liposomal bupivacaine. CONCLUSIONS Currently, there is limited evidence suggesting that liposomal bupivacaine provides longer analgesia than conventional local anesthetics when used in regional anesthesia. The analyses of multiple studies on liposomal bupivacaine for TAP blocks and brachial plexus blocks have yielded conflicting results. As a result, no definitive conclusions can be drawn about its efficacy compared to plain bupivacaine.