The use of exparel (liposomal bupivacaine) to manage postoperative pain in unilateral total knee arthroplasty patients

Liposomal Bupivacaine Suspension Can Reduce the Length of Stay of Patients Undergoing Open Reduction and Internal Fixation of Mandibular Fracture

BACKGROUND

Poorly controlled postoperative pain results in prolonged length of stay (LOS). The use of liposome bupivacaine injectable suspension (LB) for postoperative pain control is a relatively recent practice.

PURPOSE

The purpose of this study was to investigate the following. In patients undergoing open reduction and internal fixation of mandibular fracture(s), does the use of LB reduce LOS compared with regular bupivacaine?

STUDY DESIGN, SETTING, SAMPLE

We implemented a retrospective cohort study of consecutive patients with mandibular fracture(s) presented to Grady Memorial Hospital in Atlanta, GA, from January 2021 to January 2022. Adult patients diagnosed with 1 or more isolated mandibular fracture(s) and treated by open reduction and internal fixation were included. We excluded patients with non-isolated mandibular fracture(s), isolated condyle, infected, previously treated fractures, and documented allergy to amide local anesthetics and/or its preservatives.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

Primary predictor variable was local anesthetic (regular bupivacaine alone or LB/regular bupivacaine).

MAIN OUTCOME VARIABLE(S)

Primary outcome variable was LOS, defined as the number of days from surgical procedure until discharge. Secondary outcome variables were number of opioid prescription refill(s) and postoperative pain at discharge, determined with visual analogue scale.

COVARIATES

The covariates were Demographics, American Society of Anesthesiologists classification, smoking, alcohol exposure, illicit drug use, etiology, location, laterality, number of fracture(s), surgical approach, and method of maxillomandibular fixation.

ANALYSES

Univariate and bivariate analyses were calculated. Statistical significance was P < .05.

RESULTS

Sixty-two subjects met the inclusion criteria (31 subjects in each group). The mean ages in LB/regular bupivacaine and regular bupivacaine alone groups were 33.3 (±12) and 35.1 (±15.6), respectively (P = .94), the mean LOS in days was 0.23 (±0.44) in LB/regular bupivacaine and 1.48 (±1.77) in regular bupivacaine alone (P= < .001), and the mean VAS pain scores for LB/regular bupivacaine and regular bupivacaine alone groups were 0.53 (±1.07) and 1.87 (±2.66), respectively (P = .02). Mean number of opioid prescription refill(s) was 0 in LB/regular bupivacaine and 1 in regular bupivacaine alone group, respectively (P = .01).

CONCLUSION AND RELEVANCE

The use of LB/regular bupivacaine for mandibular fracture(s) results in decrease in LOS and number of opioid refills compared to regular bupivacaine alone.

Comparing Apotel and Remifentanil for Multimodal Patient-Controlled Analgesia in Postoperative Pain Management Following Total Knee Arthroplasty Surgery: A Randomized Controlled Trial

Background

Total knee arthroplasty (TKA) is a standard surgical procedure for individuals with debilitating knee arthritis. Effective postoperative pain management is essential for successful recovery, although traditional opioid-based methods have limitations.

Objectives

This study aimed to compare the efficacy of Apotel and remifentanil patient-controlled analgesia in managing postoperative pain after TKA.

Methods

This double-blind, randomized, controlled clinical trial took place at Amir-al-Momenin and Qods Hospitals in Arak, Iran, spanning from June 2022 to September 2023. Sixty-two eligible patients scheduled for knee joint replacement were randomly assigned to receive either Apotel (Group A) or remifentanil (Group R) as part of multimodal analgesia administered via a pain pump for postoperative pain relief in TKA. The study assessed hemodynamic parameters, pain levels (measured using the Visual Analog Scale), analgesic duration, and narcotic consumption. Statistical analyses were performed using SPSS v.27 and Plotly.

Results

Subjects exhibited no statistically significant differences in age, gender distribution, duration of surgery, or anesthesia. The hemodynamic status assessment in the recovery room showed no significant differences in SPO2, PR, or MAP between the groups. However, remifentanil demonstrated superior effectiveness in reducing pain over 24 hours post TKA surgery compared to Apotel, as evidenced by lower average Visual Analog Scale (VAS) scores (P < 0.001), longer duration without the need for narcotic painkillers (P < 0.001), and lower cumulative opioid analgesic consumption in Group R (P < 0.001).

Conclusions

Remifentanil demonstrates superior pain control in a multimodal pain management approach compared to Apotel, providing sustained pain reduction over 24 hours post-surgery. Moreover, remifentanil offers longer-lasting pain relief and results in lower cumulative narcotic painkiller consumption compared to Apotel.

Highly Efficient Loading of Procaine on Water-Soluble Carbon Dots toward Long-Acting Anesthesia

Safe and efficient local anesthetic delivery carriers are crucial for long-term anesthesia and analgesics in clinical treatment. But currently, most of the local anesthetic carriers still have some disadvantages such as low drug-loading capacity, drug leakage, and potential side effects. Here, we report red-emissive carbon dots (Cys-CDs) synthesized by choosing cysteine and citric acid as precursors, which contain a large and intact sp2-domain with rich hydrophilic groups around the edge. The special structure of Cys-CDs is conducive to the efficient loading of procaine (PrC) via strong π-π stacking interactions. Based on the strong noncovalent interactions between them, the PrC loaded on Cys-CDs achieved slow release in vitro and had a long-lasting nerve blocking effect in vivo, which is 4-fold more than that of free PrC. More importantly, PrC/Cys-CDs do not cause any toxicity and inflammation during treatment owing to slow release of PrC and good water solubility of Cys-CDs, thus demonstrating the potential clinical application of CDs in long-lasting analgesia.

Local Periarticular Infiltration with Dexmedetomidine Results in Superior Patient Well-Being after Total Knee Arthroplasty Compared with Peripheral Nerve Blocks: A Randomized Controlled Clinical Trial with a Follow-Up of Two Years

BACKGROUND

This study aimed to compare local periarticular infiltration (LIA) with ultra-sound guided regional anesthesia (USRA) with ropivacaine and dexmedetomidine as an additive agent in primary total knee arthroplasty (TKA).

METHODS

Fifty patients were randomized into two groups in a 1:1 ratio. Patients in the LIA group received local periarticular infiltration into the knee joint. The USRA group received two single-shot USRA blocks. Functional outcomes and satisfaction (range of movement, Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Knee Score, and Forgotten Joint Score), including well-being, were analyzed preoperatively and at five days, six weeks, and one and two years postoperatively.

RESULTS

Functional outcomes did not significantly differ between the two groups at six weeks and one and two years after the implementation of TKA. A moderate correlation was observed in the LIA group regarding well-being and pain on day five. Six weeks postoperatively, the LIA group showed significantly superior well-being but worse pain scores. No differences between the groups in well-being and functional outcomes could be observed one and two years postoperatively.

CONCLUSION

Patients treated with LIA had superior postoperative well-being in the early postoperative phase of up to six weeks. Furthermore, LIA patients had similar functionality compared to patients treated with USRA but experienced significantly more pain six weeks postoperatively. LIA leads to improved short-term well-being, which is potentially beneficial for faster knee recovery. We believe that LIA benefits fast-track knee recovery with respect to improved short-term well-being, higher practicability, and faster application.

Nanoparticle biodistribution coefficients: A quantitative approach for understanding the tissue distribution of nanoparticles

The objective of this manuscript is to provide quantitative insights into the tissue distribution of nanoparticles. Published pharmacokinetics of nanoparticles in plasma, tumor and 13 different tissues of mice were collected from literature. A total of 2018 datasets were analyzed and biodistribution of graphene oxide, lipid, polymeric, silica, iron oxide and gold nanoparticles in different tissues was quantitatively characterized using Nanoparticle Biodistribution Coefficients (NBC). It was observed that typically after intravenous administration most of the nanoparticles are accumulated in the liver (NBC = 17.56 %ID/g) and spleen (NBC = 12.1 %ID/g), while other tissues received less than 5 %ID/g. NBC values for kidney, lungs, heart, bones, brain, stomach, intestine, pancreas, skin, muscle and tumor were found to be 3.1 %ID/g, 2.8 %ID/g, 1.8 %ID/g, 0.9 %ID/g, 0.3 %ID/g, 1.2 %ID/g, 1.8 %ID/g, 1.2 %ID/g, 1.0 %ID/g, 0.6 %ID/g and 3.4 %ID/g, respectively. Significant variability in nanoparticle distribution was observed in certain organs such as liver, spleen and lungs. A large fraction of this variability could be explained by accounting for the differences in nanoparticle physicochemical properties such as size and material. A critical overview of published nanoparticle physiologically-based pharmacokinetic (PBPK) models is provided, and limitations in our current knowledge about in vitro and in vivo pharmacokinetics of nanoparticles that restrict the development of robust PBPK models is also discussed. It is hypothesized that robust quantitative assessment of whole-body pharmacokinetics of nanoparticles and development of mathematical models that can predict their disposition can improve the probability of successful clinical translation of these modalities.

Ultrasound-Triggered on Demand Lidocaine Release Relieves Postoperative Pain

Safe and non-invasive on-demand relief is a crucial and effective treatment for postoperative pain because it considers variable timing and intensity of anesthetics. Ultrasound modulation is a promising technique for this treatment because it allows convenient timed and non-invasive controlled drug release. Here, we created an ultrasound-triggered lidocaine (Lido) release platform using an amino acid hydrogel functioning as three-dimensional (3D) scaffold material (Lido-PPIX@ER hydrogel). It allows control of the timing, intensity and duration of lidocaine (Lido) to relieve postoperative pain. The hydrogel releases Lido due to the elevated reactive oxygen species (ROS) levels generated by PPIX under ultrasound triggering. The Lido-PPIX@ER hydrogel under individualized ultrasound triggering released lidocaine and provided effective analgesia for more than 72 h. The withdrawal threshold was higher than that in the control group at all time points measured. The hydrogel showed repeatable and adjustable ultrasound-triggered nerve blocks in vivo, the duration of which depended on the extent and intensity of insonation. On histopathology, no systemic effect or tissue reaction was observed in the ultrasound-triggered Lido-PPIX@ER hydrogel-treated group. The Lido-PPIX@ER hydrogel with individualized (highly variable) ultrasound triggering is a convenient and effective method that offers timed and spatiotemporally controlled Lido release to manage postoperative pain. This article presents the delivery system for a new effective strategy to reduce pain, remotely control pain, and offer timed and spatiotemporally controlled release of Lido to manage postoperative pain.

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.

Liposomal Bupivacaine Infiltration Versus Bupivacaine Hydrochloride for the Management of Unilateral Total Knee Arthroplasty in Geriatric Patients at a 287-Bed Community Hospital

Introduction: Geriatric patients receiving total knee arthroplasty (TKA) are found to have similar postoperative complications, functional scores, and perioperative mortality, as compared to younger patients. Conversely, geriatric patients often have longer lengths of stay. Periarticular injection (PAI) of liposomal bupivacaine (LB) as part of the multimodal pain management strategy is thought to improve recovery, however, mixed comparative efficacy data exists for its use in TKA.2-5. Methods: A retrospective, chart review was conducted at a 287-bed community teaching hospital. Orthopedic surgical patients who received an infiltration with liposomal bupivacaine versus bupivacaine HCl for unilateral TKA were compared. Patients identified in the electronic medical record by Diagnosis Related Group (DRG) 470-major joint replacement or reattachment of lower extremity without major complication or comorbidity codes were utilized. Patients who meet the following criteria were included: age 65 and older who underwent a TKA between 8/1/2018 to 7/31/2019 were discharged to home. Patients who have contraindications or hypersensitivity to bupivacaine formulations or a history of opioid dependence were excluded. The primary outcome is to identify whether patients who received an infiltration with liposomal bupivacaine had a lower total opioid consumption during their hospital stay. Results: A total of 114 patients who had a DRG 470 code and were above the age of 65 years were studied. There was no statistically significant difference in mean total opioid consumption (oral morphine equivalents) between the bupivacaine HCl (n = 25) and liposomal groups (n = 85) respectively, 93.76 versus 83.72 mg; P = .569. In addition, patients in both groups had similar lengths of hospital stay, 2.5 versus 3 days; P = .529 and mean pain scores until discharge 3.7 versus 4.34 on VAS; P = .305. Conclusion: The results of this drug utilization evaluation do not support a strong clinical advantage with local infiltration of liposomal bupivacaine over bupivacaine HCl in geriatric patients undergoing primary TKA surgery at this institution. There was not a statistically significant difference in mean total opioid consumption between the 2 groups. Additionally, the use of non-opioid analgesics, mean pain scores, and hospital lengths of stay were similar in both groups.

Do local liposomal bupivacaine and interscalene nerve block provide similar pain control after shoulder arthroplasty? A dual-center randomized controlled trial

BACKGROUND

Interscalene nerve block (INB) has become a popular technique for shoulder anesthesia. However, INB is associated with complication rates as high as 20%. Local liposomal bupivacaine (LLB) is an alternative to INB that potentially offers extended pain control with fewer adverse effects.

METHODS

We conducted a dual-center randomized controlled trial of 108 participants who were treated with LLB (n = 54) or INB (n = 54) to control pain after shoulder arthroplasty. We assessed visual analog scale pain scores at 6-hour intervals from 6 to 96 hours postoperatively and at the first postoperative visit. We assessed opioid medication consumption intraoperatively and on days 1, 2, 3, and 4 postoperatively, as well as the duration of hospital and postanesthesia care unit (PACU) stays.

RESULTS

At 6 hours postoperatively, the mean visual analog scale pain score was lower in the INB group (2.9 ± 3.1) than in the LLB group (5.1 ± 2.9, P < .01). The INB group consumed less opioid medication during the first 24 hours postoperatively (18 ± 12 morphine milligram equivalents) than did the LLB group (36 ± 48 morphine milligram equivalents, P = .01). The PACU stay was shorter in the INB group (102 ± 53 minutes) compared with the LLB group (139 ± 77 minutes, P < .01).

CONCLUSIONS

Compared with LLB, INB provides better pain control immediately after shoulder arthroplasty as evidenced by shorter PACU stays, lower pain scores at 6 hours postoperatively, and less opioid medication consumption during the first 24 hours postoperatively. However, no differences in outcomes were observed between groups beyond 24 hours.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Adductor Canal Block vs Liposomal Bupivacaine Periarticular Injection in Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

This study compares postoperative pain scores and functional outcomes between liposomal bupivacaine peri-articular injection (LB-PAI) vs a single-shot adductor canal block (ACB) using bupivacaine HCl in patients undergoing primary total knee arthroplasty (TKA).

METHODS

This is a randomized controlled trial of 56 patients who were treated with TKA for arthritis. Patients were randomized to receive an intraoperative LB-PAI (n = 27) or preoperative ACB using bupivacaine HCl (n = 29). Both groups were otherwise given our institutional standard multimodal pain protocol. Data on Visual Analog Scale (VAS) pain scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, knee range of motion, postoperative ambulation distance, hospital length of stay, and opioid use were collected. The total cost of each intervention was compared at the conclusion of the study.

RESULTS

Age, gender, or body mass index was similar between groups. Compared to the ACB group, the LB-PAI group trended to lower average VAS pain scores on postoperative days 0, 1, and 2 (average difference [95% confidence interval] = -0.5 [-0.7, 1.7], -1.0 [-0.1, 2.0], -0.2 [-0.8, 1.3]), and identical average VAS pain scores on postoperative days 4 and 7. These differences and all postoperative outcome measures were not statistically significant at any time point. A single 266-milligram vial of liposomal bupivacaine costs $351, and a single-shot ACB costs $893 at our institution.

CONCLUSIONS

This randomized controlled trial shows similar postoperative pain control, functional outcomes, and opioid use between LB-PAI and a single-shot ACB in patients undergoing primary TKA. However, the single-shot ACB costs $542 more than the LB-PAI at our institution.

The Efficacy of Liposomal Bupivacaine for Opioid and Pain Reduction: A Systematic Review of Randomized Clinical Trials

Background The opioid crisis has prompted surgeons to search for alternative postoperative methods of analgesia. Liposomal bupivacaine is a long-acting local anesthetic formulation used for pain, potentially reducing opioid use. Evaluation of liposomal bupivacaine as a viable alternative for pain management is needed. The objective was to assess the efficacy of randomized clinical trials (RCTs) of liposomal bupivacaine in postoperative pain management and opioid consumption. Material and Methods The authors extracted RCTs comparing liposomal bupivacaine versus placebo or active comparators for postoperative pain or opioid reduction from PubMED/MEDLINE, Cochrane Library, and ClinicalTrials.gov. Exclusion criteria included nonhuman studies, non-RCTs, pooled studies, and inability to access full text. The following variables were abstracted: surgical specialty, number of subjects, pain and opioid outcomes, and authors' financial conflicts of interest. Results We identified 77 published RCTs, of which 63 studies with a total of 6770 subjects met inclusion criteria. Liposomal bupivacaine did not demonstrate significant pain relief compared to placebo or active agents in 74.58% of RCTs. Of the studies evaluating narcotic use, liposomal bupivacaine did not show a reduction in opioid consumption in 85.71% of RCTs. Liposomal bupivacaine, when compared to standard bupivacaine or another active agent, yielded no reduction in opioid use in 83.33% and 100.00% of studies, respectively. Clinical trials with a financial conflict of interest relating to the manufacturer of liposomal bupivacaine were significantly more likely to show pain relief (OR: 14.31 [95% CI, 2.8, 73.10], P = 0.0001) and decreased opioid consumption (OR: 12.35 [95% CI 1.40, 109.07], P = 0.0237). Of the 265 unpublished RCTs on ClinicalTrials.gov, 47.54% were withdrawn, terminated, suspended, or completed without study results available. Conclusions The efficacy of liposomal bupivacaine for providing superior postoperative pain control relative to placebo or another active agent is not supported by a majority of RCTs. Underreporting of trial results and bias due to underlying financial relationships amongst authors are two major concerns that should be considered when evaluating the available evidence.

A comparison of analgesic techniques for total knee arthroplasty: A network meta-analysis

STUDY OBJECTIVE

There is no established analgesic method for postoperative total knee arthroplasty. We comprehensively compared the analgesic methods for postoperative total knee arthroplasty.

DESIGN

A network meta-analysis of randomised controlled trials was used to compare 18 interventions, which were ranked by six outcome indices, to select the best modality.

SETTING

Postoperative recovery room and inpatient ward.

PATIENTS

98 randomised controlled trials involving 7452 patients (ASA I-III) were included in the final analysis.

INTERVENTIONS

Studies that included the use of at least one of the following 12 nerve block(fascia iliaca compartment block (FIB), FNB, cFNB, single femoral nerve block (sFNB), adductor canal block (ACB), sciatic nerve block (SNB), obturator nerve block (ONB), continuous posterior lumbar plexus block (PSOAS), FNB + SNB, ACB + LIA, FNB + LIA, PCA + FNB).

MEASUREMENTS

Pain intensity was compared using Visual Analogue Scale (VAS). Also, postoperative complications, function score, hospital length of stay, morphine consumption and patient satisfaction were measured.

MAIN RESULTS

For visual analogue scale scores, continuous femoral nerve block (FNB) and FNB + sciatic nerve block (SNB) were the the most effective interventions. For reducing postoperative complications, fascia iliaca compartment block, FNB, SNB, and obturator nerve block showed the best results. For reducing postoperative morphine consumption, adductor canal block (ACB) + local infiltration analgesia (LIA) and FNB + SNB were preferred. For function scores (range of motion, Timed-Up-and-Go test), ACB and LIA were optimal choices. For reducing hospital length of stay and patient satisfaction, ACB + LIA and FNB + LIA were best, respectively.

CONCLUSIONS

Peripheral nerve block, especially FNB and ACB, is a better option than other analgesic methods, and its combination with other methods can be beneficial. Peripheral nerve block is a safe and effective postoperative analgesia method. However, our findings can only provide objective evidence. Clinicians should choose the treatment course based on the individual patient's condition and clinical situation.

Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia

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.

EDITOR’S PERSPECTIVE

Clinical Effectiveness of Liposomal Bupivacaine Administered by Infiltration or Peripheral Nerve Block to Treat Postoperative Pain

The authors provide a comprehensive summary of all randomized, controlled trials (n = 76) involving the clinical administration of liposomal bupivacaine (Exparel; Pacira Pharmaceuticals, USA) to control postoperative pain that are currently published. When infiltrated surgically and compared with unencapsulated bupivacaine or ropivacaine, only 11% of trials (4 of 36) reported a clinically relevant and statistically significant improvement in the primary outcome favoring liposomal bupivacaine. Ninety-two percent of trials (11 of 12) suggested a peripheral nerve block with unencapsulated bupivacaine provides superior analgesia to infiltrated liposomal bupivacaine. Results were mixed for the 16 trials comparing liposomal and unencapsulated bupivacaine, both within peripheral nerve blocks. Overall, of the trials deemed at high risk for bias, 84% (16 of 19) reported statistically significant differences for their primary outcome measure(s) compared with only 14% (4 of 28) of those with a low risk of bias. The preponderance of evidence fails to support the routine use of liposomal bupivacaine over standard local anesthetics.

Pain management strategies in penile implantation

The opioid epidemic continues to be a serious public health concern. Many have pointed to prescription drug misuse as a nidus for patients to become addicted to opioids and as such, urologists and other surgical subspecialists must critically define optimal pain management for the various procedures performed within their respective disciplines. Controlling pain following penile prosthesis implantation remains a unique challenge for urologists, given the increased pain patients commonly experience in the postoperative setting. Although most of the existing urological literature focuses on interventions performed in the operating room, there are many studies that examine the role of preoperative adjunctive pain medicine in diminishing postoperative narcotic requirements. There are relatively few studies looking at postoperative strategies for managing pain in prosthetic surgery with follow-up past the immediate hospitalization. This review assess the various strategies employed for managing pain following penile implantation through the lens of the current state of the opioid crisis, thus examining how urologists can responsibly treat pain without contributing to the growing threat of opioid addiction.

HTX-011 Reduced Pain and Opioid Use After Primary Total Knee Arthroplasty: Results of a Randomized Phase 2b Trial

BACKGROUND

HTX-011 is an extended-release, dual-acting local anesthetic consisting of bupivacaine and low-dose meloxicam in a novel polymer that is administered by needle-free application during surgery. The active ingredients are released from the polymer by controlled diffusion over 72 hours.

METHODS

This phase 2b, double-blind, placebo-controlled and active-controlled trial enrolled patients undergoing primary unilateral total knee arthroplasty under general anesthesia. Two hundred thirty-two patients were randomized into 4 groups: HTX-011 400 mg bupivacaine/12 mg meloxicam, applied without a needle into the surgical site, the same dose of HTX-011 with a separate 50 mg ropivacaine injection into the posterior capsule, bupivacaine hydrochloride (HCl) 125 mg injection, and saline placebo injection. Only opioids were permitted for postoperative pain rescue. Primary and key secondary endpoints were mean area under the curve of pain intensity scores over 48 hours and 72 hours, respectively, for HTX-011 groups vs placebo.

RESULTS

Both HTX-011 groups had significantly reduced mean pain intensity vs placebo through 48 and 72 hours (both P < .001). Ropivacaine added a small initial benefit in the first 12 hours. Both HTX-011 groups also had decreased mean pain intensity vs bupivacaine HCl alone through 48 and 72 hours (P < .05). The HTX-011 groups had significantly earlier discharge readiness along with lower opioid consumption through 72 hours. HTX-011 alone or with ropivacaine was well-tolerated with a safety profile similar to controls.

CONCLUSION

Needle-free application of HTX-011 400 mg bupivacaine/12 mg meloxicam provided superior pain reduction through 72 hours after total knee arthroplasty compared with placebo and bupivacaine HCl alone.

Potential application of liposomal nanodevices for non-cancer diseases: an update on design, characterization and biopharmaceutical evaluation

Liposomes, lipid-based vesicular systems, have attracted major interest as a means to improve drug delivery to various organs and tissues in the human body. Recent literature highlights the benefits of liposomes for use as drug delivery systems, including encapsulating of both hydrophobic and hydrophilic cargos, passive and active targeting, enhanced drug bioavailability and therapeutic effects, reduced systemic side effects, improved cargo penetration into the target tissue and triggered contents release. Pioneering work of liposomes researchers led to introduction of long-circulating, ligand-targeted and triggered release liposomes, as well as, liposomes containing nucleic acids and vesicles containing combination of cargos. Altogether, these findings have led to widespread application of liposomes in a plethora of areas from cancer to conditions such as cardiovascular, neurologic, respiratory, skin, autoimmune and eye disorders. There are numerous review articles on the application of liposomes in treatment of cancer, which seems the primary focus, whereas other diseases also benefit from liposome-mediated treatments. Therefore, this article provides an illustrated detailed overview of liposomal formulations, in vitro characterization and their applications in different disorders other than cancer. Challenges and future directions, which must be considered to obtain the most benefit from applications of liposomes in these disorders, are discussed.

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).

Periarticular Ketorolac Improves Outcomes for Patients With Joint Replacements

BACKGROUND

Effective analgesia after joint replacement allows for earlier mobilization, decreased length of stay, and reduced opioid use. The injection of the surgical area with ketorolac (Toradol) prior to closure has changed pain management in joint replacement surgery.

PURPOSE

This retrospective research study examined the difference between patients who received periarticular injections of ketorolac versus those who did not. Postoperative outcomes were measured in the two groups.

METHODS

Between January 2012 and December 2014, a random sample of 161 patient charts was reviewed to compare length of stay, distance ambulated in the first physical therapy (PT) session, and amount of opioids consumed.

RESULTS

Ketorolac injected into the tissue prior to closure significantly impacted outcomes. Patients who received the injection had statistically significant shorter stays, ambulated further distances with their first PT session, and used fewer opioids on postoperative day 1.

CONCLUSION

Periarticular ketorolac injections reduce pain and improve outcomes, which reduces healthcare costs.

Efficacy of Adductor Canal Block With Liposomal Bupivacaine: A Randomized Prospective Clinical Trial

This study compared the postoperative analgesic efficacy of liposomal bupivacaine as a single-administration adductor canal block (ACB) vs periarticular injection (PAI) for pain control after total knee arthroplasty (TKA). From May 2016 to June 2017, a total of 70 unilateral TKA patients were randomized into 2 groups: PAI (extended-release bupivacaine 266 mg [20-mL vial] with 20 mL of 0.5% bupivacaine hydrochloride and normal saline to a total volume of 120 mL) and ACB (subsartorial saphenous nerve using extended-release bupivacaine 266 mg [20-mL vial]). All patents underwent spinal anesthesia with comprehensive preemptive and postoperative multi-modal pain protocol. All opioids administered were converted to morphine equivalents. Pain was recorded at 4 to 12 hours on the day of surgery, and on postoperative days 1, 2, and 3. Patients and investigators other than the surgeon and anesthesiologist were blinded to the study. The difference in pain scores between the PAI and ACB groups was not statistically significant during the first 12 hours (day 0) after surgery or on postoperative day 1 (5.31 vs 4.26, P=.091). However, on postoperative day 3, the mean pain score increased in the ACB group and decreased in the PAI group (4.8 vs 1.83, P=.037). There was no statistically significant difference between the 2 groups regarding the accumulative daily converted morphine equivalent consumption or total consumption. Although the PAI group demonstrated longer lasting pain relief than the ACB group for the duration of the study, other outcomes were similar between the 2 groups. [Orthopedics. 2020; 43(1):e47-e53.].

Recent research and development of local anesthetic-loaded microspheres

This review introduces the recent research and development in local anesthetic-loaded microsphere, as efficient microspheres formulation, the efficient microspheres: optimum preparation method, high loading efficiency, and ideal release rate.

Synergistic antibacterial effects of analgesics and antibiotics against Staphylococcus aureus

The local use of analgesics and antibiotics is common during the treatment of periprosthetic joint infection (PJI). The effect of nonantimicrobial drugs on antibacterial activity is underappreciated in clinical practice. This study focuses on the novel assessment of the combined antibacterial effects of commonly used analgesics and antibiotics against methicillin-sensitive Staphylococcus aureus (MSSA)-pathogen associated with most PJIs. We identified that bupivacaine/lidocaine and ketorolac/gentamicin combinations yielded fractional inhibitory concentration indices below 0.4, indicative of synergistic antibacterial effect. Time-kill curves were used for in-depth characterization of the synergy, and the obtained results demonstrated pronounced synergistic effects of bupivacaine/lidocaine and ketorolac/gentamicin combinations against MSSA.

Ambulation milestones in post-operative physical therapy after total knee arthroplasty: how can we improve short-term outcomes?

Introduction: Post-operative day (POD) 0 physical therapy (PT) after total knee arthroplasty (TKA) has been associated with improved outcomes such as shorter hospital length of stay (LOS), though patient performance is variable. The purpose of this study was to evaluate PT performance and determine whether this affected LOS or discharge to home.Methods: Retrospective review including 412 patients who underwent TKA over 1 year. Specific data assessed included details about demographics, surgery/recovery, PT, LOS, and discharge destination.Results: Overall, 88.8% (366/412) of patients received POD 0 PT. About 73.9% of patients who did not receive POD 0 PT were prevented from doing so by reasons that kept them off of the orthopedic inpatient floor. Patients who walked greater than 10 feet on POD 0 or 100 feet on POD 1 were significantly more likely to have a shorter LOS and more likely to be discharged to home.Discussion: Objective milestones of walking 10 feet on POD 0 and 100 feet on POD 1 were associated with improved short-term outcomes. These performance markers may be useful for stratifying which patients are meeting milestones for early discharge. Late arrival to inpatient floor had the strongest associations with inability to perform PT.

Comprehensive Comparison of Liposomal Bupivacaine with Femoral Nerve Block for Pain Control Following Total Knee Arthroplasty: An Updated Systematic Review and Meta-Analysis

To compare the efficacy of liposomal bupivacaine (LB) and femoral nerve block following total knee arthroplasty, we conducted this systematic review and meta-analysis. 11 trials with 2,908 patients were included in this study. The pooled data demonstrated that total morphine consumption equivalents during the hospital stay was significantly increased in FNB group. In addition, LB has significantly better outcome in view of the postoperative functional recovery, such as the odds of fall, the incidences of straight leg rise (SLR), the number of patients who can walk independently in the day of surgery,the ambulation distance at POD1, the number of patients discharged at POD1. Consistent with the faster functional recovery, liposomal bupivacaine shortens the length of hospital stay. However, there was no significant difference between LB and FNB in terms of Visual Analogue Score (VAS) during the hospital stay. All in all, liposomal bupivacaine has significantly better outcome in view of the postoperative functional recovery and the length of hospital stay compared with femoral nerve block following the total knee arthroplasty.

Evaluation of the Efficacy of Liposomal Bupivacaine in Total Joint Arthroplasty

BACKGROUND

Appropriate pain control is one of the cornerstones necessary to promote positive clinical outcomes. A new bupivacaine liposomal formulation was designed to extend its analgesic effect for up to 72-hours post-surgery, reportedly leading to significant opioid-sparing.

METHOD

Retrospective and prospective chart review conducted in a 178-bed academic institution between January 2013 to December 2013 and August 2014 to November 2014, in 115 patients that receive hip and knee arthroplasty. The primary outcome was the measurement of average daily pain score on post-operative days 1 and 2. Secondary outcomes included length of stay, overall opioid use post-surgery and pain control satisfaction using Press-Ganey® scores.

RESULTS

The average pain scores in the HCl group were 4.64 and 4.38 (Likert score: 0-10) for POD 1 and POD 2, compared to 4.72 POD 1 and 4.2 POD 2 in the liposome group (POD 1: p = 0.413; POD 2: p = 0.303). The difference in LOS for knee arthroplasty was statistically significant [HCl group: 1.94 days (± 0.66) versus liposome group: 2.27 days (±0.77) p-value = 0.038)] favoring the standard of care. For hip arthroplasty or bilateral knee arthroplasty the differences in LOS were not statistically significant (p = 0.052 and p = 0.484 respectively). 93% of the patients in the HCl group, pain was well controlled, versus 88.5% in the liposome group with similar oxycodone IR use among groups.

CONCLUSION

Liposome bupivacaine did not offer a notable benefit compared to the HCl formulation in our study.

The Efficacy of Liposomal Bupivacaine Over Traditional Local Anesthetics in Periarticular Infiltration and Regional Anesthesia During Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Since its Food and Drug Administration approval in 2011 as a local anesthetic for postsurgical analgesia, liposomal bupivacaine (LB) has been incorporated into the periarticular injection (PAI) of many knee surgeons. The slow release of this medication from vesicles should significantly extend the duration of its analgesic effect, but current evidence has not clearly demonstrated this benefit.

METHODS

We systematically searched electronic databases including PubMed, MEDLINE, Cochrane Library, EMBASE, ScienceDirect, and Scopus, as well as the Journal of Arthroplasty web page for relevant articles. All calculations were made using Review Manager 5.3.

RESULTS

We identified 42 studies that compared LB to an alternate analgesic modality. Seventeen of these studies were controlled trials that were included in meta-analysis. Significant differences were seen in pain scores with LB over a peripheral nerve block (mean difference = 0.45, P = .02) and LB over a traditional PAI (standard mean difference = -0.08, P = .004).

CONCLUSION

While LB may offer a statistically significant benefit over a traditional PAI, the increase in pain control may not be clinically significant and it does not appear to offer a benefit in reducing opioid consumption. However, there is no standardization among current studies, as they vary greatly in design, infiltration technique, and outcome measurement, which precludes any reliable summarization of their results. Future independent studies using a standardized protocol are needed to provide clear unbiased evidence.

Ultrasound-guided adductor canal block using levobupivacaine versus periarticular levobupivacaine infiltration after totalknee arthroplasty: a randomized clinical trial

BACKGROUND

Both postoperative pain control and range of motion are important in total knee arthroplasty (TKA). However, in the literature, there is little comparison of peripheral nerve blocks and periarticular infiltration techniques using levobupivacaine. The aim of our study was to measure pain with visual analogue scale (VAS) and knee range of motion (ROM) between in patients undergoing adductor canal block (ACB) for TKA using levobupivacaine compared to periarticular levobupivacaine infiltration (PAI-L).

DESIGN AND SETTING

Prospective randomized clinical trial in a university hospital.

METHODS

Patients aged 40-85 years who underwent unilateral TKA were included; 39 were treated withperiarticular infiltration using 40 ml (0.125 mg) of levobupivacaine (PAI-L group); and 40 were treated with ACB using 20 ml of 0.25% levobupivacaine (ACB-L group). Postoperative pain scores at rest and during active physical therapy were assessed using a VAS, along with knee ROM in flexion and extension. In addition, 100-foot walking time results, total morphine consumption and time of first analgesia requirement were recorded postoperatively.

RESULTS

VAS scores at rest and during active physical therapy and the total amount of morphine consumed were lower in the ACB-L group than in the PAI-L group (P < 0.05). In contrast, knee ROM in flexion and extension and 100-foot walking times were greater in the PAI-L group than in the ACB-L group (P < 0.05).

CONCLUSION

ACB-L was superior to PAI-L regarding pain treatment after TKA; however, PAI-L was superior to ACB-L regarding postoperative ROM and walking ability.

CLINICAL TRIAL REGISTRY

ACTRN-12618000438257.

Antimicrobial effect of anesthetic-eluting ultra-high molecular weight polyethylene for post-arthroplasty antibacterial prophylaxis

Despite being a relatively safe surgery, total joint replacement is often associated with two major complications-severe post-operative pain and periprosthetic joint infection. Local sustained delivery of therapeutics to the surgical site has a potential to address these complications more effectively than current clinical approaches. Given that several analgesics were shown to possess antibacterial activity, we propose here to use analgesic-loaded ultra-high molecular weight polyethylene (UHMWPE) as a delivery vehicle to provide antimicrobial effect after an arthroplasty. Three commonly used anesthetics, lidocaine, bupivacaine, and ropivacaine, were analyzed in order to reveal the drug with the highest antibacterial activity against methicillin-sensitive Staphylococcus aureus. Having shown highest antibacterial activity in the bacterial susceptibility tests, bupivacaine was chosen to be incorporated into UHMWPE to provide antibacterial properties. Bupivacaine-loaded UHMWPE possessed moderate dose-dependent antimicrobial properties, decreasing the S. aureus proliferation rate by up to 70%. Biofilm formation was also substanitally inhibited during the first 9 h of culture as quantified by bacterial counts and SEM. This proof-of-concept study is first of its kind to demonstrate that analgesic-loaded UHMWPE can be used as part of a multimodal antimicrobial therapy. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Periarticular Knee Injection With Liposomal Bupivacaine and Continuous Femoral Nerve Block for Postoperative Pain Management After Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Local periarticular infiltration (PAI) analgesia has emerged as an important component of multimodal approaches to treat total knee arthroplasty postoperative pain. Liposomal bupivacaine may provide prolonged analgesic duration when injected into the surrounding tissues. The purpose of this study was to compare the analgesic efficacy and serum bupivacaine levels of a continuous femoral nerve block (CFNB) with bupivacaine to PAI with liposomal bupivacaine.

METHODS

Sixty-five patients undergoing primary unilateral total knee arthroplasty were randomized into 2 groups: (1) CFNB and PAI with bupivacaine (CFNB group) or (2) PAI with bupivacaine:liposomal bupivacaine mixture at the end of surgery (LB group). The primary outcome was pain intensity at maximum knee flexion 24 hours following surgery. Secondary outcomes included pain intensities at rest and movement at timed intervals and serum bupivacaine levels.

RESULTS

Patients in the CFNB group experienced lower pain scores at maximum knee flexion at 24 hours (7.91; 95% confidence interval, 7.19-8.61) compared to the LB group (8.95; 95% confidence interval, 8.42-9.48; P = .02). The mean peak serum bupivacaine level in the LB group up to 72 hours was 0.55 μg/mL versus 1.4 μg/mL for CFNB group (P = .0008) with one patient in the CFNB group exceeding the reported minimum serum bupivacaine threshold for toxicity.

CONCLUSION

While similar pain control was observed on the day of surgery for both groups, patients with a CFNB experienced lower pain intensities during maximum knee flexion at 24 hours. Total serum concentrations in LB group remained below the toxicity threshold over the study period.

The efficacy of local liposomal bupivacaine infiltration on pain and recovery after Total Joint Arthroplasty: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Total Joint Arthroplasty (TJA) is gradually emerging as the treatment of choice for end-stage osteoarthritis. In the past, Perioperative liposomal bupivacaine treatment is still a controversial subject in TJA. Therefore, we write this systematic review and meta-analysis to evaluate the efficacy of liposomal bupivacaine on pain and recovery after TJA.

MATERIALS AND METHODS

Embase, Pubmed, and Cochrane Library were comprehensively searched. Randomized controlled trials (RCTs), cohort studies were included in our meta-analysis. Twelve studies that compared liposomal bupivacaine groups with placebo groups were included in our meta-analysis. The research was reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. RCTs were included in our meta-analysis.

RESULTS

Our study demonstrated that liposomal bupivacaine group was as effective as the placebo group in term of VAS score at 24 h (P = .09), 48 h (P = .97); Postoperative nausea (P = .72); and LOS (0.27). There was significant difference in terms of total morphine consumption at 24 h (P < .0001), 48 h (P = .0008).

CONCLUSION

Our meta-analysis demonstrated that liposomal bupivacaine has similar pain control and functional recovery after TJA which compared with the control group. However, we still need large sample size, high-quality studies to explore the relationship between complications and dose response to give the final conclusion.

Impact of treatment with liposomal bupivacaine on hospital costs, length of stay, and discharge status in patients undergoing total knee arthroplasty at high-use institutions

Aims: Post-surgical pain experienced by patients undergoing total knee arthroplasty (TKA) can be severe. Enhanced recovery after surgery programs incorporating multimodal analgesic regimens have evolved in an attempt to improve patient care while lowering overall costs. This study examined clinical and economic outcomes in hospitals using liposomal bupivacaine (LB) for pain control following TKA.Methods: This retrospective observational study utilized hospital chargemaster data from the Premier Healthcare Database from January 2011 through April 2017 for the 10 hospitals with the highest number of primary TKA procedures using LB. Within these hospitals, patients undergoing TKA who received LB were propensity-score matched in a 1:1 ratio to a control group not receiving LB. Outcomes included hospital length of stay (LOS), discharge status, 30-day same-hospital readmissions, total hospitalization costs, and opioid consumption; only patients with Medicare or commercial insurance as the primary payer for TKA were considered.Results: The study population included 20,907 Medicare-insured patients (LB = 10,411; control =10,496) and 12,505 patients with commercial insurance (LB = 6,242; control = 6,263). Overall, LOS was 0.6 days shorter with LB (p < 0.0001), and patients who received LB were 1.6-times more likely to be discharged home (p < 0.0001). Total hospitalization costs for the TKA procedure were lower with LB for patients with both Medicare (-$616; P < 0.0001) and commercial insurance (-$775; p < 0.0001). Opioid consumption was lower with LB in both payer populations (p < 0.0001). No significant differences for 30-day readmissions were found.Limitations: Costs were estimated using Premier charge-to-cost ratios and limited to goods and services recorded in the chargemaster. Findings from these 10 hospitals may not be representative of other US hospitals.Conclusions: In a sub-set of 10 US hospitals with the highest use of LB for TKA, LB use was associated with shorter hospital LOS, increased home discharge, lower total hospitalization costs, and decreased opioid use after TKA.

Liposomal bupivacaine mixture has similar pain relief and significantly fewer complications at less cost compared with indwelling interscalene catheter in total elbow arthroplasty

BACKGROUND

Postoperative pain control, short-term and long-term narcotic consumption, complication rates, and costs of indwelling interscalene catheter (ISC) were compared with a liposomal bupivacaine (LBC) mixture in patients undergoing primary total elbow arthroplasty.

METHODS

Forty-four consecutive patients were identified, the first 28 with an ISC and the later 16 with intraoperative LBC injection that also included ketorolac and 0.5% bupivacaine. Medical records were reviewed for visual analog scale scores for pain, oral morphine equivalent (OME) use, complications, and facility charges.

RESULTS

Average visual analog scale scores at 24 hours, 2 weeks, 6 weeks, and 12 weeks were not significantly different. Mean OME use was significantly greater in the LBC group at 24 hours but less at 12 weeks, although this difference was not statistically significant. Twelve anesthetic-related complications occurred in the ISC group (1 major and 11 minor); 10 patients (36%) had at least 1 complication. The major complication was respiratory failure requiring emergent tracheostomy. Minor complications included leaking pump/catheters, catheters inadvertently pulled out early, global hand paresthesias, forearm paresthesias, and pain at the catheter site. There were no anesthetic-related complications in the LBC group. The average charge for the LBC mixture was $327.10; charges for ISC, including equipment and anesthesia fees, were $1472.42.

CONCLUSIONS

An LBC mixture provides similar pain relief with fewer complications at a lower cost than indwelling ISC after total elbow arthroplasty. Although the OME use in the LBC group was almost double that of the ISC group at 24 hours, there was no difference at later time points.

Solid State Characterization of Ciprofloxacin Liposome Nanocrystals

Liposomes have been widely researched as drug delivery systems; however, the solid state form of drug inside the liposome, whether it is in solution or in a solid state, is often not studied. The solid state properties of the drug inside the liposomes are important, as they dictate the drug release behavior when the liposomes come into contact with physiological fluid. Recently, a new approach of making liposomal ciprofloxacin nanocrystals was proposed by the use of an additional freeze-thawing step in the liposomal preparation method. This paper aims to determine the solid state properties of ciprofloxacin inside the liposomes after this additional freeze-thawing cycle using cryo-TEM, small-angle X-ray scattering (SAXS), and cross-polarized light microscopy (CPLM). Ciprofloxacin precipitated in the ciprofloxacin hydrate crystal form with a unit cell dimension of 16.7 Å. The nanocrystals also showed a phase transition at 93 °C, which represents dehydration of the hydrate crystals to the anhydrate form of ciprofloxacin, verified by temperature-dependent SAXS measurements. Furthermore, the dependence of the solid state form of the nanocrystals on pH was investigated in situ, and it was shown that the liposomal ciprofloxacin nanocrystals retained their crystalline form at pH 6-10. Understanding the solid state attributes of nanocrystals inside liposomes provides improved understanding of drug dissolution and release as well as opening avenues to new applications where the nanosized crystals can provide a dissolution benefit.

Prospective Randomized Trial Comparing Femoral Nerve Block With Intraoperative Local Anesthetic Injection of Liposomal Bupivacaine in Total Knee Arthroplasty

BACKGROUND

Postoperative pain after total knee arthroplasty (TKA) may impact long-term results and incidence of complications. Femoral nerve block (FNB) provides excellent pain relief after TKA, although associated risks include weakness, delayed participation in therapy, and nerve injury. Liposomal bupivacaine (LB) is a potentially longer acting local anesthetic that may reduce postoperative pain.

METHODS

We performed a prospective, randomized, double-blind study of 373 TKA patients randomized to receive either an FNB (control group), or an intraoperative periarticular injection (PAI) with LB and a placebo saline FNB (experimental group). Patients were evaluated with visual analog scores for pain, range of motion, performance of straight leg raise (SLR), walking distance, and Short Form-12 up to 1 year postoperatively.

RESULTS

Twelve and 24 hours postoperatively, the control group had significantly lower pain scores (mean 3.24 vs 3.87; P = .02) and higher range of motion (84.54° vs 78°; P < .001). The patients receiving LB PAI were significantly more likely to perform a straight leg raise 12 hours postoperatively (73% vs 50%; P = .0003). Patients in the LB (experimental) group scored better in the physical function component of the Short Form-12 (-23 vs -27, P = .01) 3 months postoperatively.

CONCLUSION

While pain scores were slightly lower in the control group in the first 24 hours after TKA compared with LB PAI, the magnitude of the difference was small, and excellent pain relief was provided by both interventions. Use of LB PAI in TKA is a reasonable alternative to FNB, which avoids the additional weakness and other risk associated with FNB procedures.

Peripheral Nerve Blocks vs Periarticular Injections in Total Knee Arthroplasty

In patients undergoing surgery, optimal pain management is associated with improved perioperative outcomes, patient satisfaction with surgery, and a more rapid functional recovery. In recent years, the employment of multimodal pain management strategies has become increasingly widespread. In particular, there has been an explosion in the use of peripheral nerve blockade and periarticular injections in total knee arthroplasty. However, there is significant variability in the administration of either modality of anesthesia. As such, a critical evaluation of the current literature is warranted to elucidate the advantages and disadvantages of each technique with the ultimate goal of further refining current pain control strategies. In this symposium, we review each of these modalities and their association with pain management, narcotic consumption, length of hospital stay, and adverse events.

Do liposomal bupivacaine infiltration and interscalene nerve block provide similar pain relief after total shoulder arthroplasty: a systematic review and meta-analysis

OBJECTIVE

Controversy still exists regarding the efficiency and safety of liposomal bupivacaine (LB) vs interscalene nerve block (INB) for pain management after total shoulder arthroplasty (TSA). The aim of the present meta-analysis was to perform a relatively credible and overall assessment to compare the efficiency and safety of LB-based infiltration vs INB for pain management after TSA.

METHODS

The PubMed, Cochrane Library, Web of Science, and EMBASE were systematically searched. Only studies published up to March 2018 comparing LB vs INB for pain control after TSA were included. The primary outcome extracted from the studies was postoperative pain score at different periods. The secondary outcomes included total opioid consumption, length of hospital stay, and complications.

RESULTS

Seven studies with 707 patients were included in this study. No statistically significant difference was observed between the LB and INB groups in pain scores at 8 hours, 12 hours, 24 hours, postoperative day (POD) 1, and POD 2. The two groups also showed comparable total opioid consumption at POD 0, POD 1, POD 2, and length of hospital stay. The LB group had a significantly higher pain score at 4 hours (standard mean difference =0.65, 95% CI=0.07 to 1.24, P=0.03) but a lower occurrence rate of complications than did the INB group (OR =0.51, 95% CI=0.28 to 0.91, P=0.02).

CONCLUSION

This meta-analysis revealed that INB provides excellent analgesic effects within 4 hours after TSA, while patients treated with LB infiltration experienced significantly less occurrence rate of complications after TSA. In general, both approaches provide similar overall pain relief and have similar opioid consumption after TSA, with no significant difference in the length of hospital stay. Nevertheless, more high-quality randomized controlled trails with long-term follow-up are still required to make the final conclusion.

Levobupivacaine Thermogel for Long-acting Analgesia

The adequate management of analgesia, by pharmacological methods or not, is a great challenge. Local anesthetics are used for pain relief, mainly by parenteral, intramuscular, catheter, and other routes of administration. The use of in situ forming systems becomes an alternative for the control of pain. The present research investigates development of thermogels containing poloxamer and levobupivacaine. All formulations were prepared by the cold method; the compatibilities of the excipients were evaluated by DSC, rheology and viscosities, transition temperature, syringeability, release kinetics, and permeation. The compatibility of the tested excipients with the drug was initially observed; all formulations had a viscosity increase at 37°C. Different delivery rates were observed in both the release and permeation studies. The developed systems maintained the in vitro release of the drug for a long period, likely decreasing side effects in vivo and avoiding the need for supplementary analgesia by other routes.

Periarticular Ropivacaine Cocktail Is Equivalent to Liposomal Bupivacaine Cocktail in Bilateral Total Knee Arthroplasty

BACKGROUND

This study compares the effectiveness of 2 commonly used periarticular injection formulations: liposomal bupivacaine and bupivacaine (EXP) and ropivacaine, epinephrine, ketorolac, and clonidine (ROP) in patients undergoing bilateral total knee arthroplasty or unicompartmental knee arthroplasty.

METHODS

Twenty-six total knee arthroplasty patients (52 knees) and 3 unicompartmental knee arthroplasty patients (6 knees) undergoing simultaneous, bilateral arthroplasty were randomized to receive periarticular injections in a blinded fashion. Even birth year patients were selected for PAI of EXP in the right knee and ROP in the left knee. This was reversed for odd birth years. Visual analog scale pain scores for each knee and patient perceived difference in knee functional recovery were recorded during physical therapy, throughout the hospitalization.

RESULTS

There was no difference in visual analog scale pain scores between the EXP and ROP injected knees at any time point during the first 2 days after surgery. Postoperative pain scores averaged 41.9 mm (range 0-100 mm) for EXP and 43.1 mm (range 0-100 mm) for ROP. Patients were unable to detect a difference in the functional recovery between their knees on postoperative day 0, 1, or 2. No complications as a result of either periarticular injection occurred.

CONCLUSION

Periarticular injections of EXP and ROP are equally effective after knee arthroplasty and patients do not appreciate differences between knees as determined by pain score or perceived functional recovery during the first 2 days after bilateral knee arthroplasty. This study demonstrates that a liposomal bupivacaine injection does not add an incremental benefit for pain control compared to a less expensive injection formulation.

Liposomal Bupivacaine vs Plain Bupivacaine in Periarticular Injection for Control of Pain and Early Motion in Total Knee Arthroplasty: A Randomized, Prospective Study

BACKGROUND

The use of multimodal pain regimens has been shown to be an effective technique for the treatment of postoperative pain after total knee arthroplasty. Periarticular injections, of both short-acting and long-acting anesthetics, have emerged as an additional method of providing significant improvement in postoperative pain relief. The purpose of this study is to compare the efficacy of periarticular injection using long-acting vs short-acting preparations.

METHODS

A randomized, prospective study of 80 consecutive patients was performed comparing liposomal bupivacaine vs plain bupivacaine periarticular injection. The primary outcomes included pain relief, total narcotic usage, and completion of physical therapy goals, specifically range of motion.

RESULTS

No significant improvements were noted between liposomal bupivacaine and plain bupivacaine injection groups in overall pain reduction, range of motion, or total narcotic usage. At 24 hours, small statistically significant differences in physical therapy pain scores were noted with liposomal bupivacaine vs plain bupivacaine and control patients, but these differences did not persist at later time points. Both preparations demonstrated statistically significant improvements in range of motion when compared to historical controls, but no differences were noted between preparations.

CONCLUSION

Overall, minimal significant differences were noted between liposomal bupivacaine and plain bupivacaine at early and late time points. Both preparations of periarticular injection demonstrated superiority over control pain regimens but were relatively equivalent to one another in direct comparison.

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

Objective

Peripheral nerve blocks for postoperative analgesia have improved block success, but analgesia efficacy has been limited by the short duration of traditional local anesthetics. The results of randomized trials comparing liposome bupivacaine with conventional local anesthetic formulations (e.g., plain bupivacaine and ropivacaine) have generated conflicting results. This study was conducted to systematically review the effectiveness of analgesic efficacy of liposome bupivacaine infiltration at the surgical site versus plain local anesthetic bupivacaine or ropivacaine in patients undergoing surgery.

Methods

PRISMA statement guidelines were followed. A search of electronic databases National Library of Medicine's PubMed database, Cochrane Database of Systematic Reviews, Embase, and Google Scholar from January 2012 to September 2017 was performed. Among the 1,612 records identified, 9 randomized controlled trials involving 779 patients were eligible for data extraction and meta-analysis.

Results

Liposome bupivacaine did not reduce postsurgical pain at rest compared to plain local anesthetics at 24 and 48 hours after surgery. Moreover, liposome bupivacaine did not reduce postoperative opioid consumption at 24, 48, or 72 hours when compared to plain local anesthetics. Liposome bupivacaine did reduce postoperative nausea when compared to plain local anesthetics (P =<0.3). There was no significant difference in hospital length of stay between study groups, the use of plain bupivacaine or ropivacaine, or among orthopedic or nonorthopedic procedures. No manifestations of local anesthetic toxicity were reported.

Conclusions

Our results suggest that liposome bupivacaine does not have an analgesic advantage when compared to plain local anesthetics at the surgical site for patients undergoing surgical procedures.

Sustained-release lidocaine sheet for pain following tooth extraction: A randomized, single-blind, dose-response, controlled, clinical study of efficacy and safety

Background

We have synthesized a sustained-release lidocaine sheet (SRLS) using biodegradable polymers and previously demonstrated its safety and long-term analgesic effect in the normal mucous membrane of healthy human volunteers.

Objectives

The aim of this clinical study was to evaluate the efficacy, safety, and appropriate dose of the SRLS for pain following tooth extraction.

Design

Randomized, single-blind, dose-response, controlled, clinical study (Phase 1/2).

Methods

The patients in this trial were enrolled between January 2014 and December 2016. A total of 99 patients were randomly divided into 5 groups as follows: the Non-administration group received the conventional extraction; the Poly Lactic-co-Glycolic Acid (PLGA) 100 mg control group received the PLGA matrix without lidocaine; the SRLS 100 mg group received a single sheet of SRLS 100 mg; the SRLS 200 mg group received double sheets of SRLS 100 mg; and the SRLS 400 mg administration group received four sheets of SRLS 100 mg. A study drug was inserted into the defect socket after the extraction, and postoperative pain intensity, satisfaction with postoperative pain relief, adverse events, and postoperative supplemental analgesic rescue use (time, dose) were investigated by patient self-report.

Results

In total, 94 (94.9%) patients completed the study. There were no significant differences in postoperative pain intensity, satisfaction with postoperative pain relief, and postoperative supplemental analgesic rescue use among the 5 groups. There were no serious side effects, including a plasma concentration increase of lidocaine, attributable to the SRLS.

Conclusions

Administration of the SRLS at 100 mg may have clinical therapeutic potential for pain relief following tooth extraction. The safety of the SRLS for patients undergoing tooth extraction was demonstrated.

Trial registration

The University Hospital Medical Information Network UMIN000011945

A Summary of the Anatomy and Current Regional Anesthesia Practices for Postoperative Pain Management in Total Knee Arthroplasty

The planning and implementation of an effective postoperative pain management program depend on the surgical technique for total knee arthroplasty (TKA), the type of regional anesthesia, and the multimodal analgesia regimen. It is imperative to understand the surgical anatomy of TKA and the relevant nerve supply of the knee for optimum perioperative patient satisfaction with respect to pain management in the patient undergoing TKA. The commonly used regional techniques have their own specific benefits and limitations. The ideal postoperative pain management should be customized for a patient to achieve the goals of effective pain control, early ambulation, faster recovery, and discharge.