The analgesic efficacy of liposomal bupivacaine compared with bupivacaine hydrochloride for the prevention of postoperative pain: a systematic review and meta-analysis with trial sequential analysis

Surgeon-administered regional nerve blocks during radical cystectomy: a feasibility study

OBJECTIVE

To describe the technique for surgeon-administered, ultrasound-guided transversus abdominis plane (SU-TAP) blocks performed during radical cystectomy as a component of multimodal, perioperative pain management.

METHODS

Retrospective, case series of patients receiving SU-TAP blocks just prior to incision for RC. TAP blocks were performed by the surgeon with a standard technique using US guidance to instill an anesthetic solution. The primary outcome was opioid consumption at the intervals of 0-12, 12-24, 24-36, and 36-48 h postoperatively. Opioid consumption was reported as oral morphine milligram equivalents (MME). Secondary outcomes included time to perform SU-TAP blocks, and safety of block procedure.

RESULTS

34 patients were included. During the median length of stay of 4 days (interquartile range [IQR] 3-7), only 30/34 (88%) of patients required opioids within the first 12 h post-op, decreasing to 38% by 48 h post-op. The median consumption decreased in the first 48 h from 21 MMEs (IQR 9-38) to 10 MMEs (IQR 8-15) at the 0-12 and 36-48 h intervals, respectively. The median time to perform block procedure was 6 min (IQR 4-8 min) and there were no safety events related to the SU-TAP blocks. Limitations include no comparative arm for opioid consumption.

CONCLUSION

Our data suggest that urologists may feasibly perform US-guided TAP blocks as a practical, efficient, and safe method of regional anesthesia. SU-TAP blocks should be considered in ERAS protocols for RC. Future comparative studies on opioid consumption compared to local infiltration and alternative block techniques are warranted.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part I): guidelines for preparing the review protocol

Comprehensive resources exist on how to plan a systematic review and meta-analysis. The objective of this article is to provide guidance to authors preparing their systematic review protocol in the fields of regional anesthesia and pain medicine. The focus is on systematic reviews of healthcare interventions, with or without an aggregate data meta-analysis. We describe and discuss elements of the systematic review methodology that review authors should prespecify, plan, and document in their protocol before commencing the review. Importantly, authors should explain their rationale for planning their systematic review and describe the PICO framework-participants (P), interventions (I),comparators (C), outcomes (O)-and related elements central to constructing their clinical question, framing an informative review title, determining the scope of the review, designing the search strategy, specifying the eligibility criteria, and identifying potential sources of heterogeneity. We highlight the importance of authors defining and prioritizing the primary outcome, defining eligibility criteria for selecting studies, and documenting sources of information and search strategies. The review protocol should also document methods used to evaluate risk of bias, quality (certainty) of the evidence, and heterogeneity of results. Furthermore, the authors should describe their plans for managing key data elements, the statistical construct used to estimate the intervention effect, methods of evidence synthesis and meta-analysis, and conditions when meta-analysis may not be possible, including the provision of practical solutions. Authors should provide enough detail in their protocol so that the readers could conduct the study themselves.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part II): guidelines for performing the systematic review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia.

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

Trends of liposomal bupivacaine utilization in major lower extremity total joint arthroplasty in the USA: a population-based study

INTRODUCTION

Liposomal bupivacaine has been marketed for the achievement of long-acting local or regional anesthesia after major lower extremity total joint arthroplasty. However, it is comparatively expensive and controversy remains regarding its ability to decrease healthcare costs. With mounting evidence suggesting non-superiority in efficacy, compared with plain bupivacaine, we sought to investigate trends in liposomal bupivacaine use and identify changes in practice.

METHODS

We identified adult patients from the Premier Healthcare Database who underwent elective total joint arthroplasty between 2012 and 2021. Prevalence and trends of liposomal bupivacaine utilization were compared on the individual patient and hospital levels. Log-rank tests were performed to assess the influence of location, teaching status, or hospital size on time to hospital-level liposomal bupivacaine termination.

RESULTS

Among 103,165 total joint arthroplasty cases, liposomal bupivacaine use increased between 2012 and 2015 (from 0.4% to 22.8%) and decreased by approximately 1%-3% annually thereafter (15.7% in 2021). Liposomal bupivacaine was ever used in approximately 60% of hospitals. Hospital-level initiation of liposomal bupivacaine use peaked in 2014 and decreased thereafter (from 32.8% in 2013 to 4.3% in 2021), while termination rates increased (from 1.4% in 2014 to 9.9% in 2019). Non-teaching hospitals and those located in the South and West regions were more likely to retain liposomal bupivacaine longer than teaching or Midwest/Northeast hospitals, respectively (p=0.023 and p=0.014).

DISCUSSION

Liposomal bupivacaine use peaked around 2015 and has been declining thereafter on individual patient and hospital levels. How these trends correlate with health outcomes and expenditures would be a strategic target for future research.

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part II): Guidelines for Performing the Systematic Review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia .

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part I): Guidelines for Preparing the Review Protocol

Comprehensive resources exist on how to plan a systematic review and meta-analysis. The objective of this article is to provide guidance to authors preparing their systematic review protocol in the fields of regional anesthesia and pain medicine. The focus is on systematic reviews of health care interventions, with or without an aggregate data meta-analysis. We describe and discuss elements of the systematic review methodology that review authors should prespecify, plan, and document in their protocol before commencing the review. Importantly, authors should explain their rationale for planning their systematic review and describe the PICO framework-participants (P), interventions (I), comparators (C), outcomes (O)-and related elements central to constructing their clinical question, framing an informative review title, determining the scope of the review, designing the search strategy, specifying the eligibility criteria, and identifying potential sources of heterogeneity. We highlight the importance of authors defining and prioritizing the primary outcome, defining eligibility criteria for selecting studies, and documenting sources of information and search strategies. The review protocol should also document methods used to evaluate risk of bias, quality (certainty) of the evidence, and heterogeneity of results. Furthermore, the authors should describe their plans for managing key data elements, the statistical construct used to estimate the intervention effect, methods of evidence synthesis and meta-analysis, and conditions when meta-analysis may not be possible, including the provision of practical solutions. Authors should provide enough detail in their protocol so that the readers could conduct the study themselves.

Peripheral Nerve Blocks for Cesarean Delivery Analgesia: A Narrative Review

Effective postoperative analgesia using multimodal approach improves maternal and neonatal outcomes after cesarean delivery. The use of neuraxial approach (local anesthetic and opioids) and intravenous adjunctive drugs, such as nonsteroidal anti-inflammatory drugs and acetaminophen, currently represents the standard regimen for post-cesarean delivery analgesia. Peripheral nerve blocks may be considered in patients who are unable to receive neuraxial techniques; these blocks may also be used as a rescue technique in selected patients. This review discusses the relevant anatomy, current evidence, and advantages and disadvantages of the various peripheral nerve block techniques. Further research is warranted to compare the analgesic efficacy of these techniques, especially newer blocks (e.g., quadratus lumborum blocks and erector spinae plane blocks). Moreover, future studies should determine the safety profile of these blocks (e.g., fascial plane blocks) in the obstetric population because of its increased susceptibility to local anesthetic toxicity.

Crystallization of short-acting and intermediate-acting local anesthetics when mixed with adjuvants: a semiquantitative light microscopy analysis

INTRODUCTION

The addition of adjuvants to short-acting local anesthetics (LA) is common practice in clinical routine to speed up block onset and decrease pain on injection. In a previous study, we observed the development of microscopic crystal precipitations after bupivacaine or ropivacaine were mixed with adjuvants; this follow-up study is intended to clarify whether crystallization (A) also occurs in short-acting or intermediate-acting LA-adjuvant mixtures, (B) changes over time, and (C) is associated with the solutions' pH.

METHODS

Lidocaine 2%, prilocaine 2%, mepivacaine 2%, procaine 2% and chloroprocaine 2% were individually mixed with clonidine, dexamethasone, dexmedetomidine, epinephrine, fentanyl, morphine or sodium bicarbonate 8.4% in clinically established ratios. For each mixture, we measured initial pH and recorded crystallization patterns at 0, 15, 30 and 60 min using a standardized, semiquantitative light microscopy approach.

RESULTS

Lidocaine 2% and mepivacaine 2% plus sodium bicarbonate 8.4%, and mepivacaine 2% plus dexamethasone developed delayed grade 5 crystallization over 1 hour. Prilocaine-based, procaine-based and chloroprocaine-based mixtures showed much less pronounced crystallization, with a maximum of grade 2. Initial pH and grade of crystallization showed weak monotonic relationships at time points t0, t15 and t30 (ρ=-0.17, 0.31 and 0.32, (all p>0.05)) and a moderate relationship time point t60 (ρ=0.57 (p=0.0003)) CONCLUSIONS: Our study revealed high grades of crystallization in lidocaine/mepivacaine-bicarbonate and mepivacaine-dexamethasone mixtures, although these were previously considered safe for local, perineural or neuraxial use. Our findings cast particular doubt on the safety of preparing these formulations for later use.

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 adjuvants added to local anaesthetics for single-injection upper extremity peripheral regional anaesthesia: A systematic review with network meta-analysis of randomised trials

BACKGROUND

Peripheral regional anaesthesia is frequently used for upper extremity surgery. To prolong the duration of analgesia, adjuvants can be added to single-injection local anaesthetics. Despite attempts to compare several adjuvants in pairwise meta-analyses, a comprehensive comparison is still missing.

OBJECTIVE

The objective of this network meta-analysis was to determine the effectiveness of adjuvants in upper extremity peripheral nerve blocks.

DESIGN

A systematic review of randomised controlled trials with network meta-analyses.

DATA SOURCES

A literature search in Embase, CENTRAL, MEDLINE and Web of Science was performed up to March 2023.

ELIGIBILITY CRITERIA

Randomised trials comparing different adjuvants injected perineurally in peripheral upper extremity nerve blocks were eligible. Frequentist network meta-analysis was conducted using a random effects model with physiological saline as the comparator. The primary endpoint was the ratio of means (ROM) of the duration of analgesia.

RESULTS

The review included 242 randomised controlled trials with a total of 17 391 patients. Twenty-eight adjuvants were compared in the largest networks. Most network estimations consisted of a high proportion of direct evidence. Fourteen adjuvants increased the duration of analgesia significantly by the following factors, ROM [95% confidence interval (CI)]: dexamethasone 1.95 (1.79 to 2.13), buprenorphine 1.83 (1.51 to 2.24), butorphanol 1.84 (1.41 to 2.39), potassium chloride 1.89 (1.15 to 3.11), dexmedetomidine 1.70 (1.59 to 1.81), sufentanil 1.70 (1.27 to 2.29), ketorolac 1.68 (1.24 to 2.27), midazolam 1.55 (1.24 to 1.94), tramadol 1.52 (1.32 to 1.75), nalbuphine 1.50 (1.30 to 1.72), morphine 1.43 (1.09 to 1.88), magnesium sulfate 1.42 (1.20 to 1.67), clonidine 1.36 (1.24 to 1.50) and fentanyl 1.23 (1.08 to 1.40). Inconsistency in network meta-analysis was substantial. Overall side effect rates were low with all adjuvants.

CONCLUSION

The best interventions to prolong the duration of analgesia were dexamethasone, followed by dexmedetomidine, opioids, electrolytes, ketorolac and midazolam. There are general concerns about the quality of underlying studies and the risk of publication bias.

TRIAL REGISTRATION

PROSPERO 2018 CRD42018115722.

The postoperative analgesic efficacy of liposomal bupivacaine versus long-acting local anaesthetics for peripheral nerve and field blocks: A systematic review and meta-analysis, with trial sequential analysis

BACKGROUND

Liposomal bupivacaine is claimed by the manufacturer to provide analgesia for up to 72 h postoperatively.

OBJECTIVES

To compare the postoperative analgesic efficacy of liposomal bupivacaine versus long-acting local anaesthetics for peripheral nerve or field blocks.

DESIGN

A systematic review and meta-analysis with trial sequential analysis.

DATA SOURCES

MEDLINE, Embase and Web of Science, among others, up to June 2022.

ELIGIBILITY CRITERIA

We retrieved randomised controlled trials comparing liposomal bupivacaine versus bupivacaine, levobupivacaine or ropivacaine for peripheral nerve and field blocks after all types of surgery. Our primary endpoint was rest pain score (analogue scale 0 to 10) at 24 h. Secondary endpoints included rest pain score at 48 and 72 h, and morphine consumption at 24, 48 and 72 h.

RESULTS

Twenty-seven trials including 2122 patients were identified. Rest pain scores at 24 h were significantly reduced by liposomal bupivacaine with a mean difference (95% CI) of -0.9 (-1.4 to -0.4), I2  = 87%, P  < 0.001. This reduction in pain scores persisted at 48 h and 72 h with mean differences (95% CI) of -0.7 (-1.1 to -0.3), I2  = 82%, P  = 0.001 and -0.7 (-1.1 to -0.3), I2  = 80%, P  < 0.001, respectively. There were no differences in interval morphine consumption at 24 h ( P  = 0.15), 48 h ( P  = 0.15) and 72 h ( P  = 0.07). The quality of evidence was moderate.

CONCLUSIONS

There is moderate level evidence that liposomal bupivacaine reduces rest pain scores by 0.9 out of 10 units, when compared with long-acting local anaesthetics at 24 hours after surgery, and by 0.7 up to 72 hours after surgery.

Incidence of postoperative administration of opioids in dogs undergoing a tibial plateau leveling osteotomy after intra-operative liposomal bupivacaine administration with or without morphine epidural

OBJECTIVE

To determine the influence of two intraoperative pain management protocols on the need for additional opioids in patients receiving an epidural and periarticular liposomal bupivacaine (PLB) vs. PLB alone in the 12-24 h period after undergoing a TPLO.

STUDY DESIGN

Retrospective study.

ANIMALS

One hundred seventy-four dogs with cranial cruciate ligament tears presenting for TPLO.

METHODS

Medical records of dogs presenting for a unilateral or bilateral cranial cruciate ligament tear who had a TPLO performed were reviewed for signalment, weight, body condition score, and peri-operative pain management protocol. Dogs were divided into two groups: those who received an epidural and PLB, and those who received only PLB. Post-operative opioid administration was recorded for each group.

RESULTS

Patients who received an epidural and PLB received fewer postoperative opioids. There were 36% fewer opioid injections administered to dogs who received epidurals compared to dogs who did not receive epidurals (IRR) (95% CI) = 0.64 (0.45-0.92), P = 0.02). BCS was not a significant predictor of the post-operative opioid requirement (IRR (95% CI) = 1.3 (0.75-2.4), P = 0.38). When adjusting for BCS as a possible confounder, there were 39% fewer opioid injections in dogs who received epidurals than dogs without (IRR (95% CI) = 0.61 (0.42-0.88), P = 0.009).

CONCLUSIONS

The incidence of postoperative opioid administration was significantly diminished in patients receiving both an epidural and PLB.

CLINICAL SIGNIFICANCE

Administration of an epidural in addition to infiltration of PLB significantly decreased the incidence of postoperative opioid administration in dogs undergoing a TPLO.

Evaluation of the effects of bupivacaine combined with sugammadex on the duration of the nociceptive blockade in sciatic nerve blocks: a controlled, double-blind animal study

BACKGROUND

Animal and other experimental studies have demonstrated increased block time and quality when α- and β-cyclodextrin drugs are combined with local anesthetics. However, to our knowledge, no study has utilized γ-cyclodextrins in such a combination. In the present study, we used an animal model to evaluate the effects of different doses of the combined administration of γ-cyclodextrin (sugammadex) and bupivacaine on the duration of sciatic nerve blocks in rats.

METHODS

Sciatic nerve blocks were performed with a 0.20 ml mixture in all groups. For the non-experimental groups, this mixture consisted of 0.2 ml saline (Sham group), 0.2 ml sugammadex (Group S), or 0.16 ml bupivacaine 0.5% and 0.04 ml saline (Group B). For the experimental groups, 0.16 ml bupivacaine 0.5% was administered along with 0.01 ml sugammadex and 0.03 ml saline (Group BS1), 0.02 ml sugammadex and 0.02 ml saline (Group BS2), or 0.04 ml sugammadex (Group BS4). Proprioception, nociception, and motor function were evaluated until the sciatic block was completely reversed.

RESULTS

Motor, proprioceptive, and nociceptive blockades occurred within 5 min in all experimental groups. In Group BS4, the duration of the motor, proprioceptive, and nociceptive blockades was significantly increased compared with the other experimental groups. However, in Groups BS1 and BS2, only the duration of the nociceptive blockade was significantly increased.

CONCLUSIONS

The combined administration of sugammadex and bupivacaine for sciatic nerve blocks in rats led to a significant increase in the duration of motor, proprioceptive, and nociceptive blockades.

Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called 'adjuvants' are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.

Measures to prolong duration of sensory block after regional anaesthesia

PURPOSE OF REVIEW

The duration of single-injection regional anaesthesia is limited due to the inherent pharmacological properties of local anaesthetics. The ideal duration of a regional anaesthesia block lasting for the first 24 h postoperatively can be stated, while a residual analgesic effect thereafter is desirable.The aim of this review is to present current options to prolong the duration of action of single-injection peripheral regional anaesthesia in the ambulatory setting. Secondly, this review outlines and discusses the latest evidence regarding the clinical use of adjuvants and sustained-release local anaesthetics.

RECENT FINDINGS

Extended-release formulations of local anaesthetics such as liposomal bupivacaine have been developed to prolong regional anaesthesia up to 96 h. Recent studies, however, show that the actual effects remain far behind expectations and that the efficacy is only marginally better than bupivacaine hydrochloride.Adjuvants to local anaesthetics have been studied extensively with heterogenous results. Dexamethasone and alpha-2 agonists range among the most effective measures to prolong single-injection nerve blocks.Continuous nerve blocks and catheter techniques may prolong regional anaesthesia very effectively, but are less cost-effective regarding block procedure, postoperative care and handling logistical issues especially in ambulatory surgery.

SUMMARY

In conclusion, adjuvants are the recommended measure to prolong regional anaesthesia where needed. With good evidence supporting it, dexamethasone is the most effective adjuvant, followed by dexmedetomidine. Both have few side effects and a favourable safety profile. However, a preferable duration of analgesia lasting for the first 24 h postoperatively is still not reliably achievable.

Sternotomy Wound Infiltration With Liposomal Versus Plain Bupivacaine for Postoperative Analgesia After Elective Cardiac Surgery

OBJECTIVES

Poor pain control after cardiac surgery can be associated with postoperative complications, longer recovery, and development of chronic pain. The authors hypothesized that adding liposomal bupivacaine (LB) to plain bupivacaine (PB) will provide better and long-lasting analgesia when used for wound infiltration in median sternotomy.

STUDY DESIGN

Prospective, randomized, and double-blinded clinical trial.

SETTING

Single institution, tertiary care university hospital.

PARTICIPANTS

Adult patients who underwent elective cardiac surgery through median sternotomy.

INTERVENTIONS

A single surgeon performed wound infiltration of LB plus PB or PB into the sternotomy wound, chest, and mediastinal tube sites.

MEASUREMENTS AND MAIN RESULTS

Patients were followed up for 72 hours for pain scores, opioid consumption, and adverse events. Sixty patients completed the study for analysis (LB group [n = 29], PB group [n = 31]). Patient characteristics, procedural variables, and pain scores measured at specific intervals from 4 hours until 72 hours postoperatively did not reveal any significant differences between the groups. Mixed-model regression showed that the trend of mean pain scores at movement in the LB group was significantly (p = 0.01) lower compared with the PB group. Opioid consumption over 72 hours was not significantly different between the 2 groups (oral morphine equivalents; median [interquartile range], 139 [73, 212] mg in LB v 105 [54, 188] mg in PB, p = 0.29). Recovery characteristics and adverse events were comparable.

CONCLUSIONS

LB added to PB for sternotomy wound infiltration during elective cardiac surgery did not significantly improve the quality of postoperative analgesia.

Mepivacaine Versus Bupivacaine in Adult Surgical Patients: A Meta-analysis, Trial Sequential Analysis of Randomized Controlled Trials

PURPOSE

Evidence supporting the choice between mepivacaine and bupivacaine is inconclusive. This meta-analysis aims to determine whether mepivacaine can reach a similar effect to bupivacaine after surgeries.

DESIGN

A meta-analysis, trial sequential analysis of randomized controlled trials (RCTs).

METHODS

RCTs were identified in PubMed, EMBASE (Ovid), Medline (Ovid), and Cochrane Library using a controlled vocabulary (MeSH) and keywords. There were no date and language restrictions. We strictly included RCTs comparing mepivacaine with bupivacaine. The primary outcome was motor function recovery time. Secondary outcomes included postoperative analgesic requirement, transient neurologic symptoms (TNS), pain score at 24 hours, length of stay (LOS), duration of analgesia, complications, and patient satisfaction. A trial sequential analysis (TSA) was performed for motor function recovery time, postoperative analgesic requirement, and TNS.

FINDINGS

Seven RCTs with a total of 672 patients were included. Return of motor function was quicker in patients who received mepivacaine than in those who received bupivacaine (weighted mean differences [WMD] = -2.23 minutes; 95% confidence intervals [CI], -3.58 to -0.88; P = .02; I² = 97.08%; TSA adjusted CI -17.52 to -10.9). Postoperative analgesic requirement was significantly more with mepivacaine (risk ratio [RR] = 3.23; 95% CI, 1.37-7.62; P = .01; I² = 55.11%; TSA adjusted CI 5.73-63.27). Duration of analgesia (WMD = -8.83 hours; 95% CI, -11.75 to -7.90; P < .001; I² = 0%) and LOS (WMD = -3.95 hours; 95% CI, -4.83 to -3.07; P < .001; I² = 0%) in group mepivacaine was significantly shorter compared with bupivacaine. There were no differences for TNS (RR = 3.90; 95% CI, 0.94-16.22; P = .062; I² = 72.23%), postoperative pain score (standard mean differences [SMD] = 0; 95% CI, -0.10 to 0.10; P = .972; I² = 0%), complications (RR = 1; 95% CI, 0.70-1.43; P = .998; I² = 0%), and satisfaction (RR = 0.97; 95% CI, 0.85-1.11; P = .40; I² = 45%) between bupivacaine and mepivacaine.

CONCLUSIONS

Mepivacaine appears to yield a faster return of motor function and shorter LOS compared with bupivacaine. and may be more popular in short-stay and outpatient surgery. However, the results of TSA indicate that more high-quality trials are needed to confirm the true effects.

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.

Comparing bupivacaine alone to liposomal bupivacaine plus bupivacaine in interscalene blocks for total shoulder arthroplasty: a randomized, non-inferiority trial

Introduction

Interscalene brachial plexus blocks are a commonly performed procedure to reduce pain following total shoulder arthroplasty. Liposomal bupivacaine has been purported to prolong the duration of brachial plexus blocks for up to 72 hours; however, there has been controversy surrounding the analgesic benefits of this drug. Our hypothesis was that an interscalene block performed with bupivacaine alone would be non-inferior to a combination of liposomal bupivacaine and bupivacaine with respect to opioid consumption following total shoulder arthroplasty.

Methods

Subjects presenting for primary total shoulder arthroplasty were randomized in a 1:1 ratio to an ultrasound-guided, single-injection interscalene block with either a combination of liposomal bupivacaine and bupivacaine (LB group) or bupivacaine without additive (Bupi group). The primary outcome of this study was 72-hour postoperative cumulative opioid consumption (in oral morphine equivalents) with a non-inferiority margin of 22.5 mg. Secondary outcomes included pain scores, patient satisfaction with analgesia and patient reported duration of sensory block.

Results

Seventy-six subjects, 38 from the Bupi group and 38 from the LB group, completed the study. Analysis of the primary outcome showed a 72-hour cumulative geometric mean oral morphine equivalent consumption difference of 11.9 mg (95% CI −6.9 to 30.8) between groups (calculated on the log scale). This difference constitutes approximately 1.5 tablets of oxycodone over 3 days. No secondary outcomes showed meaningful differences between groups.

Discussion

Interscalene brachial plexus blocks performed with bupivacaine alone did not demonstrate non-inferiority compared to a mixture of liposomal bupivacaine plus bupivacaine with regards to 72-hour cumulative opioid consumption following total shoulder arthroplasty. However, the difference between groups did not appear to be clinically meaningful.

Repurposing of parenterally administered active substances used to treat pain both systemically and locally

Pain is a constant in our lives. The efficacy of drug therapy administered by the parenteral route is often limited either by the physicochemical characteristics of the drug itself or its adsorption-distribution-metabolism-excretion (ADME) mechanisms. One promising alternative is the design of innovative drug delivery systems that can improve the pharmacokinetics |(PK) and/or reduce the toxicity of traditionally used drugs. In this review, we discuss several products that have been approved by the main regulatory agencies (i.e., nano- and microsystems, implants, and oil-based solutions), highlighting the newest technologies that govern both locally and systemically the delivery of drugs. Finally, we also discuss the risk assessment of the scale-up process required, given the impact that this approach could have on drug manufacturing. Teaser: The management of pain by way of the parenteral route can be improved using complex drug delivery systems (e.g., micro- and nanosystems) which require high-level assessment and shorten the regulatory pathway.

Clinical care pathways for ambulatory total shoulder arthroplasty

PURPOSE OF REVIEW

Total shoulder arthroplasty (TSA) is growing in popularity and is increasingly done on an ambulatory basis. This review examines recent developments in anesthesia and analgesia for ambulatory shoulder surgery. Pathway components are discussed and a sample pathway is described.

RECENT FINDINGS

Adoption of pathways for shoulder surgery improves patient experience by reducing pain, opioid use, and side effects while improving patient satisfaction. Long-acting nerve blockade using adjuvants like dexamethasone provide long-lasting analgesia without rebound pain. Peripheral nerve blockade provides better analgesia than peri-articular injection of local anesthetic. There are multiple approaches to nerve blockade for shoulder surgery to consider, including interscalene, superior trunk, supraclavicular, and anterior suprascapular nerve blocks. Multimodal analgesia should include acetaminophen and nonsteroidal anti-inflammatory drugs, but routine gabapentinoids should not be used.

SUMMARY

Anesthesiologists should lead the way to create and implement pathways for ambulatory total shoulder arthroplasty, incorporating appropriate patient selection, patient education, long-lasting nerve blockade, and multimodal analgesia.

[Liposomal bupivacaine-No breakthrough in postoperative pain management]

One of the main limitations concerning the use of local anesthetics is due to their restricted duration of action. In recent years, liposomal formulations with prolonged release kinetics have been developed to extend the pharmacological duration of action of the 1‑stage peripheral regional anesthesia (single-shot procedure) and thus bring about a longer duration of action. The focus here is particularly on achieving postoperative freedom from pain for at least 24 h (or even better 48 h) and thus early mobilization of patients using on-demand medication causing (at most) minor local sensory blockade without causing motor impairments (at least that is the ideal). Therefore, methods of utilizing slow-release drugs as seen in liposomal carrier systems have experienced increasing scientific attention in the last few years. A common modern pharmacological example with a theoretically significantly longer duration of action is liposomal bupivacaine, an amide local anesthetic. Due to a multivesicular liposome structure, the retarded release of the active component bupivacaine HCl leads to a theoretical pharmacological effectiveness of up to 72 h. Previous studies consistently showed a safety profile comparable to conventional bupivacaine HCl. Liposomal bupivacaine has been approved by the U.S. Food and Drug Administration (FDA) under the trade name Exparel© (Pacira Pharmaceuticals, Parsippany, NJ, USA) since 2011; however, its use is currently limited to local wound infiltration, transverse abdominis plane (TAP) blocks, and interscalene nerve blocks of the brachial plexus. In 2020, the European Medicines Agency (EMA) also approved the use of liposomal bupivacaine for blockade of the brachial plexus or the femoral nerve and as a field block or for wound infiltration to treat postoperative pain. So far, studies on the clinical effectiveness of liposomal bupivacaine have been very heterogeneous and there have been no conclusive meta-analyses with sufficient rigor or significance. Recent systematic reviews and meta-analyses, combining the results of clinical studies regarding the analgesic efficiency of liposomal bupivacaine in different fields of application, consistently refuted any benefit of clinical relevance provided by the liposomal formulation. There is currently sufficient evidence to now end the ongoing debate around liposomal bupivacaine. The aim of this work is to give the reader a current, evidence-based overview of this substance.

Interscalene Brachial Plexus Block with Liposomal Bupivacaine versus Standard Bupivacaine with Perineural Dexamethasone: A Noninferiority Trial

BACKGROUND

The interscalene nerve block provides analgesia for shoulder surgery. To extend block duration, provide adequate analgesia, and minimize opioid consumption, the use of adjuvants such as dexamethasone as well as the application of perineural liposomal bupivacaine have been proposed. This randomized, double-blinded, noninferiority trial hypothesized that perineural liposomal bupivacaine is noninferior to standard bupivacaine with perineural dexamethasone in respect to average pain scores in the first 72 h after surgery.

METHODS

A total of 112 patients undergoing ambulatory shoulder surgery were randomized into two groups. The liposomal bupivacaine group received a 15-ml premixed admixture of 10 ml of 133 mg liposomal bupivacaine and 5 ml of 0.5% bupivacaine (n = 55), while the bupivacaine with dexamethasone group received an admixture of 15 ml of 0.5% standard bupivacaine with 4 mg dexamethasone (n = 56), respectively. The primary outcome was the average numerical rating scale pain scores at rest over 72 h. The mean difference between the two groups was compared against a noninferiority margin of 1.3. Secondary outcomes were analgesic block duration, motor and sensory resolution, opioid consumption, numerical rating scale pain scores at rest and movement on postoperative days 1 to 4 and again on postoperative day 7, patient satisfaction, readiness for postanesthesia care unit discharge, and adverse events.

RESULTS

A liposomal bupivacaine group average numerical rating scale pain score over 72 h was not inferior to the bupivacaine with dexamethasone group (mean [SD], 2.4 [1.9] vs. 3.4 [1.9]; mean difference [95% CI], -1.1 [-1.8, -0.4]; P < 0.001 for noninferiority). There was no significant difference in duration of analgesia between the groups (26 [20, 42] h vs. 27 [20, 39] h; P = 0.851). Motor and sensory resolutions were similar in both groups: 27 (21, 48) h versus 27 (19, 40) h (P = 0.436) and 27 [21, 44] h versus 31 (20, 42) h (P = 0.862), respectively. There was no difference in opioid consumption, readiness for postanesthesia care unit discharge, or adverse events.

CONCLUSIONS

Interscalene nerve blocks with perineural liposomal bupivacaine provided effective analgesia similar to the perineural standard bupivacaine with dexamethasone. The results show that bupivacaine with dexamethasone can be used interchangeably with liposomal bupivacaine for analgesia after shoulder surgery.

EDITOR’S PERSPECTIVE

Novel Local Anesthetics in Clinical Practice: Pharmacologic Considerations and Potential Roles for the Future

The treatment of pain, both acute and chronic, has been a focus of medicine for generations. Physicians have tried to develop novel ways to effectively manage pain in surgical and post-surgical settings. One intervention demonstrating efficacy is nerve blocks. Single-injection peripheral nerve blocks (PNBs) are usually preferred over continuous PNBs, since they are not associated with longer lengths of stay. The challenge of single injection PNBs is their length of duration, which at present is a major limitation. Novel preparations of local anesthetics have also been studied, and these new preparations could allow for extended duration of action of anesthetics. An emerging preparation of bupivacaine, exparel, uses a multivesicular liposomal delivery system which releases medication in a steady, controlled manner. Another extended-release local anesthetic, HTX-011, consists of a combination of bupivacaine and low-dose meloxicam. Tetrodotoxin, a naturally occurring reversible site 1 sodium channel toxin derived from pufferfish and shellfish, has shown the potential to block conduction of isolated nerves. Neosaxitoxin is a more potent reversible site 1 sodium channel toxin also found in shellfish that can also block nerve conduction. These novel formulations show great promise in terms of the ability to prolong the duration of single injection PNBs. This field is still currently in development, and more researchers will need to be done to ensure the efficacy and safety of these novel formulations. These formulations could be the future of pain management if ongoing research continues to prove positive effects and low side effect profiles.

Day-One Pain Reductions after Hip and Knee Replacement when Buprenorphine-Clonidine-Dexamethasone is added to Bupivacaine Nerve/Plexus Blocks: A Randomized Clinical Trial

OBJECTIVE

To compare pain outcome reports of patients undergoing hip or knee replacement who received single-injection nerve/plexus blocks with plain bupivacaine (BPV) to patients who received injections of buprenorphine-clonidine-dexamethasone (BCD) admixed with BPV.

DESIGN

Prospective, parallel arms, randomized, double-blind trial.

SETTING

A single Veterans hospital.

SUBJECTS

98 Veterans, scheduled for total hip or knee replacement surgery, with spinal as the primary anesthetic.

METHODS

Participants were randomized to BPV-BCD or plain BPV groups. They underwent nerve/plexus blocks in the L2-L4 and L4-S3 distributions in advance of joint replacement surgery. The primary outcome was change in pain from baseline during the post-operative day assessed by the total pain score in the short-form McGill Pain Questionnaire-v2 (SF-MPQ-2). Secondary outcomes were pain during movement, pain interference, range of motion, mobility, and quality of recovery.

RESULTS

On post-operative day one, the SF-MPQ-2 total score for the BPV-BCD group demonstrated greater pain reduction compared to the plain BPV group (mean difference 1.8 points, 95% CI 0.6 to 3.0, P = 0.003). The BPV-BCD group also had larger reductions in pain during movement in the surgical joint and less pain interference, along with increased range of hip and knee flexion, compared to the plain BPV group. Outcomes of mobility and quality of recovery were not different between groups.

CONCLUSIONS

Preoperative BPV-BCD blocks in the L2-L4 and L4-S3 nerve distributions for hip and knee replacements led to less pain on post-operative day one and increased knee and hip range of motion, compared to plain BPV blocks.