Analgesic efficacy of liposomal bupivacaine for surgical site infiltration: a single-outcome meta-analysis (the best we could do)

Lessons learnt in evidence-based perioperative pain medicine: changing the focus from the medication and procedure to the patient

Over time, the focus of evidence-based acute pain medicine has shifted, from a focus on drugs and interventions (characterized by numbers needed to treat), to an appreciation of procedure-specific factors (characterized by guidelines and meta-analyses), and now anesthesiologists face the challenge to integrate our current approach with the concept of precision medicine. Psychometric and biopsychosocial markers can potentially guide clinicians on who may need more aggressive perioperative pain management, or who would respond particularly well to a given analgesic intervention. The challenge will be to identify an easily assessable set of parameters that will guide perioperative physicians in tailoring the analgesic strategy to procedure and patient.

Analgesic Effectiveness of Liposomal Bupivacaine versus Plain Local Anesthetics for Abdominal Fascial Plane Blocks: A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

Liposomal bupivacaine is reported to prolong the duration of analgesia when used for abdominal fascial plane blocks compared to plain local anesthetics; however, evidence from randomized trials is mixed. This meta-analysis aims to compare the analgesic effectiveness of liposomal bupivacaine to plain local anesthetics in adults receiving abdominal fascial plane blocks.

METHODS

Randomized trials comparing liposomal bupivacaine and plain (nonliposomal) local anesthetics in abdominal fascial plane blocks were sought. The primary outcome was area under the curve rest pain between 24 to 72 h postoperatively. Secondary outcomes included rest pain at individual timepoints (1, 6, 12, 24, 48, and 72 h); analgesic consumption at 0 to 24, 25 to 48, and 49 to 72 h; time to analgesic request; hospital stay duration; and opioid-related side effects. Data were pooled using the Hartung-Knapp-Sidik-Jonkman random effects method.

RESULTS

Sixteen trials encompassing 1,287 patients (liposomal bupivacaine, 667; plain local anesthetics, 620) were included. The liposomal bupivacaine group received liposomal bupivacaine mixed with plain bupivacaine in 10 studies, liposomal bupivacaine alone in 5 studies, and both preparations in 1 three-armed study. No difference was observed between the two groups for area under the curve pain scores, with a standardized mean difference (95% CI) of -0.21 cm.h (-0.43 to 0.01; P = 0.058; I2 = 48%). Results were robust to subgroup analysis based on (1) potential conflict of interest and (2) mixing of plain local anesthetics with liposomal bupivacaine. The two groups were not different for any of the day 2 or day 3 secondary outcomes.

CONCLUSIONS

This systematic review and meta-analysis suggests similar analgesic effectiveness between liposomal bupivacaine and plain local anesthetics when used for fascial plane block of the abdominal wall. The authors' analysis does not support an evidence-based preference for liposomal bupivacaine compared to plain local anesthetics for abdominal fascial plane blocks.

EDITOR’S PERSPECTIVE

Free academic discourse and the law: the case of liposomal bupivacaine

Liposomal bupivacaine has been the topic of intense academic debate over the past years culminating in an industry-initiated libel lawsuit against the American Society of Anesthesiologists and various other defendants. In this Daring Discourse, we first aim to provide a general overview of main themes in the ongoing controversy: (1) between-study heterogeneity, (2) the high number of negative high-quality reviews and meta-analyses, (3) publication bias in the context of an active role of industry and (4) difference between statistical and clinical significance. We then discuss the contents of the lawsuit, its potential implications and what the recent resolution of this lawsuit means for the future of research and the academic discourse on liposomal bupivacaine.

The effect of liposomal bupivacaine for surgical wound infiltration: A meta‐analysis of randomised controlled trials

Liposomal bupivacaine (LB) has consistently been considered a potential analgesic for surgical wound infiltration. However, the evidence of its analgesic effectiveness remains unclear. In this meta-analysis, we attempted to identify the potential clinical role of LB wound infiltration in different surgical procedures. Randomised controlled trials (RCTs) comparing LB with non-liposomal local anaesthetics and placebos were retrieved from six electronic databases. The primary outcome was cumulative morphine equivalent consumption within 24, 48, and 72 hours after surgery. Approximately 2659 patients from 22 studies were included in the meta-analysis. Compared to the control, LB-wound infiltration did not reduce the postoperative morphine consumption at 24 hours (weighted mean difference [WMD], -0.60 mg; 97.5% confidence interval [CI], -2.78 to 1.59 mg; P = 0.54), 48 hours (WMD, -1.00 mg; 97.5% CI, -3.23 to 1.24; P = 0.32) or 72 hours (WMD, 0.50 mg; 97.5% CI, -0.67 to 1.67; P = 0.33). Similarly, secondary outcome analysis did not reveal any additional benefits of LB in any other pain-related outcomes. LB was not associated with any adverse effects. Overall, LB does not appear to improve the postoperative analgesic, rehabilitation, or safety outcomes. Current evidence does not support the routine use of LB for wound infiltration following surgical procedures.