Abstract and Introduction
Abstract
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.
Introduction
Pain is one of the most common adverse events after surgery. It can be highly distressing for patients and has a significant impact on patient satisfaction.[1] Pain can prolong postanesthesia care unit (PACU) and hospital stay as well as slow postoperative recovery.[2] In addition, both pain and postoperative opioid use are associated with increased risk of complications, such as atelectasis and ileus. One way of managing postoperative pain while minimizing opioid consumption is using regional anesthesia. Regional anesthesia techniques (eg, brachial plexus block and transversus abdominis plane [TAP] block) have been shown in numerous studies to reduce postoperative pain and opioid requirements.
One of the main limitations, however, is that single-injection regional anesthesia techniques have limited duration of analgesia, with limited evidence for analgesic effects beyond 24 hours postoperatively. One alternatve is using catheter-based techniques, which continuously infuse local anesthetic to the target area. However, catheter-based regional anesthesia techniques are more technically challenging and resource intensive.
Liposomal bupivacaine is a lipid emulsion formulation, where bupivacaine is contained in biodegradable liposomes.[3] Liposomes confer the advantage of slowly losing integrity in vivo, which results in a sustained release of bupivacaine into surrounding tissue.[4] This mechanism prolongs analgesic duration, which varies depending on individual technique and anatomy, but has been reported to be as long as 72 hours.[5] As such, liposomal bupivacaine wound infiltration has demonstrated its clinical efficacy in prolonging the duration of analgesia and reducing opioid requirement.[6] In regional anesthesia, local anesthetic was deposited around the major nerve trunk and may achieve more effective anesthesia or analgesia. It therefore stands to reason that liposomal bupivacaine may also prolong the duration of analgesia with regional anesthesia. A 2016 Cochrane review identified 7 studies—most of which were incomplete study reports—and concluded that inadequate evidence to evaluate the efficacy of liposomal bupivacaine in regional anesthesia.[7] Since the publication of the above review, there have been several new studies on this topic. We therefore perform this systematic review to summarize the recent evidence on the use of liposomal bupivacaine compared to conventional local anesthetics for regional anesthesia.