Liposome Bupivacaine Compared to Plain Local Anesthetics to Reduce Postsurgical Pain: An Updated Meta-Analysis of Randomized Controlled Trials

The Benefits of Local Anesthesia Used in Mastectomy Without Reconstruction

BACKGROUND

The opioid epidemic has driven renewed interest in local anesthesia to reduce postoperative opioid use. Our objective was to determine if local anesthesia decreased hospital pain scores, oral morphine equivalents (OME), length of stay (LOS), and nausea/vomiting.

METHODS

Single institution retrospective study of females who underwent mastectomy without reconstruction.

RESULTS

Overall, 712 patients were included; 63 (8.8%) received bupivacaine (B), 512 (72%) liposomal bupivacaine (LB), and 137 (19%) no local. 95% were discharged on POD1. Liposomal bupivacaine use increased from 2014 to 2019. Additional factors associated with use of local regimen were surgeon and extent of axillary surgery. Fewer patients used postop opioids during their hospital stay if any local was used compared to none (76 vs 88%; 0.003). Compared to none, local had shorter mean PACU LOS (95 vs 87 min; P = .02), lower mean intraoperative-OME (96 vs 106; P < .001), and lower mean postoperative OME/hr (1.4 vs 1.8 P = .001). Multivariable analysis (MVA) showed lower OME/hr with LB compared to B and none (P = .002); this translates to 22 mg and 30 mg of oxycodone in a 24-hr period, respectively. MVA showed lower POD1 pain scores with LB relative to none (P = .049). Local did not impact nausea/emesis.

CONCLUSION

Local anesthesia was superior to no local in several measures. However, a consistent benefit of a specific local anesthetic agent was not demonstrated (LB vs B). A prospective study is warranted to determine the optimal local regimen for this cohort and further inform clinical relevance.

Liposomal Bupivacaine in Dentistry and Oral and Maxillofacial Surgery. A Review of Human and Veterinary Literature

This article reviews the human and veterinary literature regarding liposome encapsulated bupivacaine use in dentistry and oral and maxillofacial surgery. The purpose of this review is to present available information on this local anesthetic in a manner that will allow veterinary dentists and oral and maxillofacial surgeons to use evidence-based information when considering incorporating liposomal bupivacaine into their practice. The twelve human clinical studies and three veterinary reports that met the literature search criteria do not support the use of liposomal bupivacaine in veterinary dentistry and oral and maxillofacial surgery.

Comparison of in vitro and in vivo Toxicity of Bupivacaine in Musculoskeletal Applications

The recent societal debate on opioid use in treating postoperative pain has sparked the development of long-acting, opioid-free analgesic alternatives, often using the amino-amide local anesthetic bupivacaine as active pharmaceutical ingredient. A potential application is musculoskeletal surgeries, as these interventions rank amongst the most painful overall. Current literature showed that bupivacaine induced dose-dependent myo-, chondro-, and neurotoxicity, as well as delayed osteogenesis and disturbed wound healing in vitro. These observations did not translate to animal and clinical research, where toxic phenomena were seldom reported. An exception was bupivacaine-induced chondrotoxicity, which can mainly occur during continuous joint infusion. To decrease opioid consumption and provide sustained pain relief following musculoskeletal surgery, new strategies incorporating high concentrations of bupivacaine in drug delivery carriers are currently being developed. Local toxicity of these high concentrations is an area of further research. This review appraises relevant in vitro, animal and clinical studies on musculoskeletal local toxicity of bupivacaine.

Pain management after laparoscopic appendectomy: Comparative effectiveness of innovative pre-emptive analgesia using liposomal bupivacaine

BACKGROUND

Laparoscopic appendectomy is standard of care for appendicitis in the US. Pain control that limits opioids is an important area of research given the opioid epidemic. This study examined post-appendectomy inpatient opioid use and pain scores following intraoperative use of liposomal bupivacaine (LB) versus non-liposomal bupivacaine.

METHODS

This was a retrospective cohort study of 155 adults who underwent laparoscopic appendectomy for acute appendicitis. Patients were divided into four cohorts based on the analgesia administered: (i) bupivacaine hydrochloride (BH)± epinephrine; (ii) undiluted LB; (iii) LB diluted with normal saline; and (iv) LB diluted with BH.

RESULTS

Baseline demographic/clinical attributes, intra-operative findings, and post-operative pain scores were equivalent across cohorts. Post-operative pre-discharge opioid use was higher in the BH vs. LB cohorts (mean 60.4 vs. 46.0, 35.5, and 30.4 morphine milligram equivalents, respectively; p < 0.001).

CONCLUSIONS

Pre-emptive analgesia with LB during laparoscopic appendectomy can reduce inpatient opioid use without significantly increasing post-operative pain scores.

Biodegradable Antimicrobial Agent/Analgesic/Bone Morphogenetic Protein-Loaded Nanofibrous Fixators for Bone Fracture Repair

Purpose

Postoperative infection and pain management are of great concern to orthopedic surgeons. Although there are several protocols available to deal with these aspects, they are fraught with complications, such as cartilage damage, cardiovascular and neurological intoxication, and systemic adverse responses. Therefore, it is necessary to develop safe and effective perioperative protocols. In the current study, antimicrobial agents/analgesics/growth factor-embedded biodegradable hybrid fixators (polycaprolactone fixator + poly[lactide-co-glycolide] sheath-core structured nanofibers) for bone fracture repair were designed.

Methods

The biodegradable hybrid fixators were fabricated using solution-extrusion three-dimensional printing and electrospinning. In vitro, the characteristics of the hybrid fixators were examined. Additionally, the release of the incorporated vancomycin, ceftazidime, lidocaine, and bone morphogenetic protein-2 (BMP-2) was evaluated. The in vivo efficacy including drug-eluting properties, fracture repair, and pain management of the biomolecule-loaded nanofibrous fixators was investigated in rabbit rib-fracture models.

Results

The nanofibrous fixators released vancomycin, ceftazidime, and lidocaine in a sustained manner under both in vitro and in vivo conditions and protected BMP-2 from burst release. The implantation of these hybrid fixators around the fractured rib significantly improved animal activities and bone union, indicating that the inclusion of analgesic in the fixator effectively reduced postsurgical pain and thereby helped in recovery.

Conclusion

The novel biomolecule-loaded nanofibrous hybrid fixators resulted in excellent therapeutic outcomes. These fixators may be effective in the repair of rib fractures in clinical settings and may help mitigate surgical complications, such as infection, nonunion, and intolerable postoperative pain.

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

BACKGROUND/IMPORTANCE

Liposomal bupivacaine (LB) is a prolonged release formulation of conventional bupivacaine designed for prolonging local or peripheral regional single injection anesthesia. To this day, the benefit of the new substance on relevant end points is discussed controversial.

OBJECTIVE

The objective was to determine whether there is a difference in postoperative pain scores and morphine consumption between patients treated with LB and bupivacaine hydrochloride in a systematic review and meta-analysis.

EVIDENCE REVIEW

Randomized controlled trials (RCT) were identified in Embase, CENTRAL, MEDLINE and Web of Science up to May 2020. Risk of bias was assessed using Cochrane methodology. Primary end points were the mean pain score difference and the relative morphine equivalent (MEQ) consumption expressed as the ratio of means (ROM) 24 and 72 hours postoperatively.

FINDINGS

23 RCTs including 1867 patients were eligible for meta-analysis. The mean pain score difference at 24 hours postoperatively was significantly lower in the LB group, at -0.37 (95% CI -0.56 to -0.19). The relative MEQ consumption after 24 hours was also significantly lower in the LB group, at 0.85 (0.82 to 0.89). At 72 hours, the pain score difference was not significant at -0.25 (-0.71 to 0.20) and the MEQ ratio was 0.85 (0.77 to 0.95).

CONCLUSION

The beneficial effect on pain scores and opioid consumption was small but not clinically relevant, despite statistical significance. The effect was stable among all studies, indicating that it is independent of the application modality.

Local anaesthetic adjuncts for peripheral regional anaesthesia: a narrative review

Moderate-to-severe postoperative pain persists for longer than the duration of single-shot peripheral nerve blocks and hence continues to be a problem even with the routine use of regional anaesthesia techniques. The administration of local anaesthetic adjuncts, defined as the concomitant intravenous or perineural injection of one or more pharmacological agents, is an attractive and technically simple strategy to potentially extend the benefits of peripheral nerve blockade beyond the conventional maximum of 8-14 hours. Historical local anaesthetic adjuncts include perineural adrenaline that has been demonstrated to increase the mean duration of analgesia by as little as just over 1 hour. Of the novel local anaesthetic adjuncts, dexmedetomidine and dexamethasone have best demonstrated the capacity to considerably improve the duration of blocks. Perineural dexmedetomidine and dexamethasone increase the mean duration of analgesia by up to 6 hour and 8 hour, respectively, when combined with long-acting local anaesthetics. The evidence for the safety of these local anaesthetic adjuncts continues to accumulate, although the findings of a neurotoxic effect with perineural dexmedetomidine during in-vitro studies are conflicting. Neither perineural dexmedetomidine nor dexamethasone fulfils all the criteria of the ideal local anaesthetic adjunct. Dexmedetomidine is limited by side-effects such as bradycardia, hypotension and sedation, and dexamethasone slightly increases glycaemia. In view of the concerns related to localised nerve and muscle injury and the lack of consistent evidence for the superiority of the perineural vs. systemic route of administration, we recommend the off-label use of systemic dexamethasone as a local anaesthetic adjunct in a dose of 0.1-0.2 mg.kg^-1 for all patients undergoing surgery associated with significant postoperative pain.

Liposomes for Intra-Articular Analgesic Drug Delivery in Orthopedics: State-of-Art and Future Perspectives. Insights from a Systematic Mini-Review of the Literature

Background and objectives: Liposomal structures are artificial vesicles composed of one or several lamellae of phospholipids which surround an inner aqueous core. Given the amphoteric nature of phospholipids, liposomes are promising systems for drug delivery. The present review provides an updated synthesis of the main techniques for the production of liposomes for orthopedic applications, focusing on the drawbacks of the conventional methods and on the advantages of high pressure techniques. Materials and Methods: Articles published in any language were systematically retrieved from two major electronic scholarly databases (PubMed/MEDLINE and Scopus) up to March 2020. Nine articles were retained based on the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) guidelines. Results: Liposome vesicles decrease the rate of inflammatory reactions after local injections, and significantly enhance the clinical effectiveness of anti-inflammatory agents providing controlled drug release, reducing toxic side effects. Conclusions: This review presents an update on the improvement in musculoskeletal ailments using liposome treatment.

Postoperative analgesic efficacy of modified continuous transversus abdominis plane block in laparoscopic colorectal surgery: a triple-blind randomized controlled trial

BACKGROUND

The optimal opioid-sparing analgesic regimen following laparoscopic colorectal surgery (LCS) remains uncertain. We sought to determine the efficacy of low-dose bupivacaine infusion via surgeon-inserted modified continuous transversus abdominis plane (mcTAP) catheters after LCS.

METHODS

A parallel-group, placebo-controlled, randomized single-centre trial was conducted between April 2017 and February 2018. Block-of-four randomization and allocation concealment by sequentially-numbered, opaque sealed envelopes were used. Patients, surgeons and assessors were blinded. Fifty-two patients were randomized to receive either 0.2% bupivacaine or saline through mcTAP catheters. A 5 ml bolus followed by a 72 h infusion at 2 ml/h was started, with patient-controlled fentanyl analgesia and oral paracetamol given on demand. Primary outcomes were fentanyl consumptions in the first 24 h, second 24 h, and third 24 h following surgery. Secondary outcomes were pain numeric rating scores, recovery outcomes and complications.

RESULTS

Twenty-five patients in the bupivacaine group and 26 in the control group were analysed. Patients in the bupivacaine group required significantly less fentanyl overall (106.1 vs 484.5 mcg, p < 0.001) and at all time points (first 24 h: 61.0 vs 324.3 mcg, p < 0.001; second 24 h: 36.3 vs 119.0 mcg, p = 0.033; third 24 h: 8.8 vs 41.2, p = 0.030) when compared to placebo. Significantly lower pain scores at rest at 6 h (2.32 vs 4.0, p = 0.002), and 12 h (1.80 vs 3.08, p = 0.011) and on coughing at 6 h (4.56 vs 5.84, p = 0.019), 12 h (3.76 vs 4.96, p = 0.009), and 24 h (3.44 vs 4.24, p = 0.049) as well as significantly lower opioid-related complications such as nausea or vomiting (9 (36%) vs 1 (4%), p = 0.005) were observed in the bupivacaine group. There were no major block-related complications, and recovery outcomes were similar in both groups.

CONCLUSIONS

McTAP block reduces postoperative fentanyl consumption and pain scores after LCS, highlighting its role as a safe and useful opioid-sparing analgesia.

REGISTRATION NUMBER

TCTR20150831001 (Thai Clinical Trials Registry). Full trial protocol can be assessed at https://www.clinicaltrials.in.th/ .

The effect of ultrasound-guided erector spinae plane block on postsurgical pain: a meta-analysis of randomized controlled trials

Background

The effect of erector spinae plane block has been evaluated by clinical trials leading to a diversity of results. The main objective of the current investigation is to compare the analgesic efficacy of erector spinae plane block to no block intervention in patients undergoing surgical procedures.

Methods

We performed a quantitative systematic review of randomized controlled trials in PubMed, Embase, Cochrane Library, and Google Scholar electronic databases from their inception through July 2019. Included trials reported either on opioid consumption or pain scores as postoperative pain outcomes. Methodological quality of included studies was evaluated using Cochrane Collaboration’s tool.

Results

Thirteen randomized controlled trials evaluating 679 patients across different surgical procedures were included. The aggregated effect of erector spinae plane block on postoperative opioid consumption revealed a significant effect, weighted mean difference of − 8.84 (95% CI: − 12.54 to − 5.14), (P < 0.001) IV mg morphine equivalents. The effect of erector spinae plane block on post surgical pain at 6 h compared to control revealed a significant effect weighted mean difference of − 1.31 (95% CI: − 2.40 to − 0.23), P < 0.02. At 12 h, the weighted mean difference was of − 0.46 (95% CI: − 1.01 to 0.09), P = 0.10. No block related complications were reported.

Conclusions

Our results provide moderate quality evidence that erector spinae plane block is an effective strategy to improve postsurgical analgesia.

The Effect of Intraoperative Methadone Compared to Morphine on Postsurgical Pain: A Meta-Analysis of Randomized Controlled Trials

Methods

We performed a quantitative systematic review of randomized controlled trials in PubMed, Embase, Cochrane Library, and Google Scholar electronic databases. Meta-analysis was performed using the random effects model, weighted mean differences (WMD), standard deviation, 95% confidence intervals, and sample size. Methodological quality was evaluated using Cochrane Collaboration's tool.

Results

Seven randomized controlled trials evaluating 337 patients across different surgical procedures were included. The aggregated effect of intraoperative methadone on postoperative opioid consumption did not reveal a significant effect, WMD (95% CI) of −0.51 (−1.79 to 0.76), (P=0.43) IV morphine equivalents. In contrast, the effect of methadone on postoperative pain demonstrated a significant effect in the postanesthesia care unit, WMD (95% CI) of −1.11 (−1.88 to −0.33), P=0.005, and at 24 hours, WMD (95% CI) of −1.35 (−2.03 to −0.67), P < 0.001.

Conclusions

The use of intraoperative methadone reduces postoperative pain when compared to morphine. In addition, the beneficial effect of methadone on postoperative pain is not attributable to an increase in postsurgical opioid consumption. Our results suggest that intraoperative methadone may be a viable strategy to reduce acute pain in surgical patients.

The Role of Exparel Plus Meloxicam for Postoperative Pain Management

PURPOSE OF REVIEW

Acute postoperative pain reduction is a major target against the opioid crisis. While opioids have traditionally been the mainstay for postoperative analgesia, current practice has focused on a multimodal approach to pain control, including ultrasound-guided blocks with longer acting local anesthetic agents.

RECENT FINDINGS

Non-steroidal anti-inflammatory drugs (NSAIDs), such as meloxicam, are an important class of medications utilized to manage pain in the perioperative period. An additional treatment used in perioperative or postoperative pain relief is Exparel, a bupivacaine (sodium channel blocker) liposomal injectable suspension with a 3-4-day duration of action. The long-acting mechanism and formulation of Exparel consistently has demonstrated decreased opioid use and pain scores in patients undergoing many different surgical procedures. A concern is that pH negatively alters the efficacy of bupivacaine, as in cases of inflamed tissue and acidic fluid pH. For this reason, a combination medication with both meloxicam and bupivacaine has been developed, which normalizes pH and has anti-inflammatory and anti-pain conduction properties. Clinical studies demonstrate that this combination agent can be extremely beneficial in treating postoperative pain. This manuscript summarizes the newest developments with regard to liposomal bupivacaine and the non-steroidal meloxicam, their roles in effective treatment of postoperative pain, contraindications, special considerations of using these medications, and future considerations. HTX-011 pairs up a new extended-release formulation of the local anesthetic bupivacaine with meloxicam, a well-established non-steroidal anti-inflammatory drug (NSAID).

Tetramethylpyrazine attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells through regulating apoptosis, autophagy and oxidative damage

Background: Bupivacaine (BUP) acts as a local anesthetic, which is extensively used for clinical patients but could generate neurotoxicity in neurons. Tetramethylpyrazine (TET) exhibits strong neuron protective effects against neurotoxicity. Hence, we investigate the effect of TET on BUP-induced neurotoxicity in SH-SY5Y cells.

Methods: CCK-8 assay was used to detect cell proliferation in SH-SY5Y cells. In addition, Western blotting was used to examine Bax, Bcl-2, active caspase 3, LC3II, Beclin 1 and p-62 protein levels in cells. Moreover, ELISA assay was used to detect the levels of total glutathione (GS), superoxide dismutase (SOD) and malondialdehyde (MDA) in cells.

Results: In this study, we found that TET attenuated the neurotoxicity of BUP on SH-SY5Y cells. Meanwhile, TET alleviated BUP-induced apoptosis in SH-SY5Y cell via decreasing the expressions of active caspase-3 and Bax and increasing the expression of Bcl-2. In addition, monodansylcadaverine staining assay and Western blotting results confirmed that TET induced autophagy in SH-SY5Y cells via increasing the LC3II/I and Beclin 1 levels. Furthermore, TET attenuated BUP-induced oxidative damage in SH-SY5Y cells via upregulation of the levels of total GS and SOD and downregulation of the level of MDA. Interesting, the protective effects of TET against BUP-induced neurotoxicity in SH-SY5Y cells were reversed by autophagy inhibitor 3-methyladenine (3MA).

Conclusion: These data indicated that TET may play a neuroprotective role via inhibiting apoptosis and inducing autophagy in SH-SY5Y cells. Therefore, TET may be a potential agent for the treatment of human neurotoxicity induced by BUP.

Application of TAP Block in Laparoscopic Urological Surgery: Current Status and Future Directions

PURPOSE OF REVIEW

Amid the opioid crisis, postoperative pain management is a major challenge for practitioners. Recent pain management guidelines emphasize the importance of using regional anesthesia as part of opioid-sparing multimodal analgesia. This report aims to review recent evidence regarding the utilization of transversus abdominis plane (TAP) block in minimally invasive urologic surgery.

RECENT FINDINGS

TAP block has been shown to improve early and late pain at rest, and to reduce opioid consumption after minimally invasive surgery. These benefits have indirectly reduced the incidence of postoperative delirium, pneumonia, urinary retention, and falls. Compared to epidural analgesia, TAP block provides similar pain control, has a lower incidence of hypotension, and is associated with a shorter length of stay. Few studies focus specifically on the outcomes of TAP block in minimally invasive urologic surgery. TAP block decreases postoperative pain and reduces opioid consumption without increasing complications. TAP block should be integrated as an indispensable component in enhanced recovery after surgery protocols.