Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia
Authors: David L Stahl
Tristan E Weaver
Faraj W Abdallah
Michael K Essandoh
Brendan Sheehy
Nasir Hussain
Richard Brull
Journal: Anesthesiology (2021)
Discipline: CLINICAL MEDICINE
Keywords: liposomal bupivacaine; peripheral nerve block; analgesia; effectiveness; randomized trials

Abstract:  Background: Liposomal bupivacaine is purported to extend analgesia of peripheral nerve blocks when administered perineurally. However, evidence of the clinical effectiveness of perineural liposomal bupivacaine is mixed. This meta-analysis seeks to evaluate the effectiveness of perineural liposomal bupivacaine in improving peripheral nerve block analgesia as compared with nonliposomal local anesthetics. Methods: The authors identified randomized trials evaluating the effectiveness of peripheral nerve block analgesic that compared liposomal bupivacaine with nonliposomal local anesthetics. The primary outcome was the difference in area under the receiver operating characteristics curve (AUC) of the pooled 24- to 72-h rest pain severity scores. Secondary outcomes included postoperative analgesic consumption, time to first analgesic request, incidence of opioid-related side effects, patient satisfaction, length of hospital stay, liposomal bupivacaine side effects, and functional recovery. AUC pain scores were interpreted in light of a minimal clinically important difference of 2.0 cm ¬∑ h. Results: Nine trials (619 patients) were analyzed. When all trials were pooled, AUC pain scores ¬± SD at 24 to 72 h were 7.6 ¬± 4.9 cm ¬∑ h and 6.6 ¬± 4.6 cm ¬∑ h for nonliposomal and liposomal bupivacaine, respectively. As such, perineural liposomal bupivacaine provided a clinically unimportant benefit by improving the AUC (95% CI) of 24- to 72-h pain scores by 1.0 cm ¬∑ h (0.5 to 1.6; P = 0.003) compared with nonliposomal bupivacaine. Excluding an industry-sponsored trial rendered the difference between the groups nonsignificant (0.7 cm ¬∑ h [-0.1 to 1.5]; P = 0.100). Secondary outcome analysis did not uncover any additional benefits to liposomal bupivacaine in pain severity at individual timepoints up to 72 h, analgesic consumption, time to first analgesic request, opioid-related side effects, patient satisfaction, length of hospital stay, and functional recovery. No liposomal bupivacaine side effects were reported. Conclusions: Perineural liposomal bupivacaine provided a statistically significant but clinically unimportant improvement in the AUC of postoperative pain scores compared with plain local anesthetic. Furthermore, this benefit was rendered nonsignificant after excluding an industry-sponsored trial, and liposomal bupivacaine was found to be not different from plain local anesthetics for postoperative pain and all other analgesic and functional outcomes. High-quality evidence does not support the use of perineural liposomal bupivacaine over nonliposomal bupivacaine for peripheral nerve blocks. 

Retracted: No

PubPeer comments:
 This paper seems to be part of a legal challenge brought by a drug manufacturer, described in this [press release](http: www.globenewswire.com news-release 2021 04 14 2210311 0 en Pacira-BioSciences-Seeks-Court-Injunction-to-Protect-Clinical-Integrity-of-EXPAREL-in-the-Face-of-Scientifically-Flawed-and-Misleading-Information-Published-in-Anesthesiology.html). Among other claims, the suit is described as alleging incomplete disclosures of conflicts of interest by the authors. From this paper: u201d**Competing Interests**. Dr. Essandoh is a consultant for Boston Scientific (Marlborough, Massachusetts) and S4 Medical (Cleveland, Ohio). Dr. Weaver is a consultant for Medtronic (Dublin, Ireland). The remaining authors declare no competing interests.  , 
 See also https: retractionwatch.com 2021 04 15 pharma-company-demands-retraction-damages-in-lawsuit-against-journal ,