Evolving Role of Local Anesthetics in Managing Postsurgical Analgesia

A new long-acting analgesic formulation for postoperative pain management

Local anesthetics (LA), as part of multimodal analgesia, have garnered significant interest for their role in delaying the initiation of opioid therapy, reducing postoperative opioid usage, and mitigating both hospitalization duration and related expenses. Despite numerous endeavors to extend the duration of local anesthetic effects, achieving truly satisfactory long-acting analgesia remains elusive. Drawing upon prior investigations, vesicular phospholipid gels (VPGs) emerge as promising candidates for extended-release modalities in small-molecule drug delivery systems. Therefore, we tried to use the amphiphilicity of phospholipids to co-encapsulate levobupivacaine hydrochloride and meloxicam, two drugs with different hydrophilicity, to obtain a long-term synergistic analgesic effect. Initially, the physicochemical attributes of the formulation were characterized, followed by an examination of its in vitro release kinetics, substantiating the viability of extending the release duration of the dual drugs. Sequentially, in vivo investigations encompassing pharmacokinetic profiling and assessment of analgesic efficacy were undertaken, revealing a prolonged release duration of up to 120 h and attainment of optimal postoperative analgesia. Subsequently, inquiries into the mechanism underlying synergistic analgesic effects and safety evaluations pertinent to the delivery strategy were pursued. In summation, we successfully developed a promising formulation to achieve long-acting analgesia.

A review of local anesthetic-induced heart toxicity using human induced pluripotent stem cell-derived cardiomyocytes

Local anesthetic (LA) cardiotoxicity is one of the main health problems in anesthesiology and pain management. This study reviewed the reported LA-induced cardiac toxicity types, risk factors, management, and mechanisms, with attention to the use of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in heart toxicity research. Important scientific databases were searched to find relevant articles. We briefly assessed the reported cardiotoxic effects of different types of LA drugs, including ester- and amide-linked LA agents. Furthermore, cardiotoxic effects and clinical manifestations, strategies for preventing and managing LA-induced cardiotoxic effects, pharmacokinetics, pharmacodynamics, and sodium channel dynamics regarding individual variability and genetic influences were discussed in this review. The applications and importance of hiPSC-CMs cellular model for evaluating the cardiotoxic effects of LA drugs were discussed in detail. This review also explored hiPSC-CMs' potential in risk assessment, drug screening, and developing targeted therapies. The main mechanisms underlying LA-induced cardiotoxicity included perturbation in sodium channels, ROS production, and disorders in the immune system response due to the presence of LA drugs. Furthermore, drug-specific characteristics including pharmacokinetics and pharmacodynamics are important determinants after LA drug injection. In addition, individual patient factors such as age, comorbidities, and genetic variability emphasize the need for a personalized approach to mitigate risks and enhance patient safety. The strategies outlined for the prevention and management of LA cardiotoxicity underscore the importance of careful dosing, continuous monitoring, and the immediate availability of resuscitation equipment. This comprehensive review can be used to guide future investigations into better understanding LA cardiac toxicities and improving patient safety.

Sustained release local anesthetics for pain management: relevance and formulation approaches

This review attempted to ascertain the rationale for the formulation of sustained-release local anesthetics and summarize the various formulation approaches designed to date to achieve sustained and localized local analgesic effects. The incidence of pain, which is the concern of patients as well as health care professionals, is increasing due to accidents, surgical procedures, and other diseases. Local anesthetics can be used for the management of moderate to severe acute and chronic pain. They also allow regional analgesia, in situations where the cause and source of the pain are limited to a particular site or region, without the need for loss of consciousness or systemic administration of other analgesics thereby decreasing the risk of potential toxicities. Though they have an interesting antipain efficacy, the short duration of action of local anesthetics makes the need for their multiple injections or opioid adjuvants mandatory. To overcome this problem, different formulations are being designed that help achieve prolonged analgesia with a single dose of administration. Combination with adjuvants, liposomal formulations, lipid-based nanoparticles, thermo-responsive nanogels, microspheres, microcapsules, complexation with multivalent counterions and HP-β-CD, lipid-based nanoparticles, and bio-adhesive films, and polymeric matrices are among the approaches. Further safety studies are required to ensure the safe and effective utilization of sustained-release local anesthetics. Moreover, the release kinetics of the various formulations should be adequately established.

Identifying risk factors for chronic postsurgical pain and preventive measures: a comprehensive update

INTRODUCTION

Chronic postsurgical pain (CPSP) is a prevalent condition that can diminish health-related quality of life, cause functional deficits, and lead to patient distress. Rates of CPSP are higher for certain types of surgeries than others (thoracic, breast, or lower extremity amputations) but can occur after even uncomplicated minimally invasive procedures. CPSP has multiple mechanisms, but always starts as acute postsurgical pain, which involves inflammatory processes and may encompass direct or indirect neural injury. Risk factors for CPSP are largely known but many, such as female sex, younger age, or type of surgery, are not modifiable. The best strategy against CPSP is to quickly and effectively treat acute postoperative pain using a multimodal analgesic regimen that is safe, effective, and spares opioids.

AREAS COVERED

This is a narrative review of the literature.

EXPERT OPINION

Every surgical patient is at some risk for CPSP. Control of acute postoperative pain appears to be the most effective approach, but principles of good opioid stewardship should apply. The role of regional anesthetics as analgesics is gaining interest and may be appropriate for certain patients. Finally, patients should be better informed about their relative risk for CPSP.

Safety and Efficacy of Liposomal Bupivacaine Supraclavicular Nerve Blocks in Open Treatment of Distal Radius Fractures: A Perioperative Pain Management Protocol

INTRODUCTION

Distal radius fractures (DRFs) are common fractures requiring surgical fixation. The literature varies regarding opioid prescribing habits, opioid consumption, and postoperative pain scores. We hypothesized that the preoperative administration of a liposomal bupivacaine (LB) supraclavicular nerve block would be safe and effective in controlling postoperative pain.

METHODS

A standardized pain management protocol was implemented at a single institution from July 2021 to March 2022 for patients undergoing open reduction internal fixation of DRF. Protocol elements included a preoperative LB supraclavicular nerve block and a multimodal postoperative pain regimen. Primary clinical outcomes included postoperative pain scores and number of opioid tablets consumed.

RESULTS

Twenty patients underwent a newly implemented protocol. The average age was 56 years. Mean number of oxycodone 5-mg tablets consumed was 4.1 (median, 2.5), and mean visual analog scale pain score at first postoperative appointment was 2.8. There were no incidences of missed acute carpal tunnel postoperatively. When compared with an institutional historical control (n = 189), number of opioid pills prescribed was reduced by 60% (21.4 vs 8.6 tablets, P < 0.0001), and no patients had unscheduled health care contact because of uncontrolled pain (22% vs 0%, P < 0.016).

CONCLUSIONS

Liposomal bupivacaine supraclavicular nerve blocks are safe and effective in the treatment of postoperative pain after open reduction internal fixation of DRF. Patients consumed <5 oxycodone tablets on average, which is less than many recommend prescribed quantities (>20-30 tablets). Patients had low pain scores (2.8/10) at the first postoperative follow-up. To our knowledge, this is the first study demonstrating the utility of LB in this clinical setting.

A Systematic Review of Non-Opioid Pain Management in Chiari Malformation (Type 1) Patients: Current Evidence and Novel Therapeutic Opportunities

Chiari Malformation Type I (CM) includes a range of cranial abnormalities at the junction of the skull with the spine, with common symptoms including pain and headaches. Currently, CM pain is managed medically through anti-inflammatory drugs, muscle relaxants, and opioids, while surgical management includes posterior fossa decompression. Given the adverse effects of opioid use, and an ongoing opioid epidemic, there is a need for safe, non-opioid alternatives for clinical pain management. This systematic review was performed to provide an update on the current literature pertaining to the treatment of CM pain with non-opioid alternatives. A literature search was performed in June 2022 utilizing the PubMed and Google Scholar databases, and articles were identified that included information regarding non-opioid pain management in CM patients. A total of 90 articles were obtained from this search, including 10 relevant, drug-specific studies. Two independent reviewers selected and included all relevant articles based on the chosen search criteria to minimize bias risk. Currently available treatments for neurosurgical pain management include anticonvulsants, corticosteroids, NSAIDs, anti-inflammatory drugs, NMDA receptor antagonists, local anesthetics, nerve blocks, scalp blocks, and neuromuscular blocks. While more information is needed on the use of non-opioid pain management, the present literature provides potential evidence of its efficacy amongst the CM patient population, on account of the success that non-opioid pain management has demonstrated within other neurological pain syndromes. Further research into non-pharmacological pain management would also benefit the CM population and could be generalized to related conditions.

Safety and technical success of diphenhydramine as an alternative local anaesthetic agent for radiology procedures

AIM

To evaluate retrospectively the safety and technical success of subcutaneous diphenhydramine as an alternative local anaesthetic for radiology procedures.

MATERIALS AND METHODS

Between January 2000 and April 2021, 84 image-guided procedures were performed in 81 adult patients (mean age 61 years, 86% female) using 1% injectable diphenhydramine as a local anaesthetic. Indications were history of severe allergy to "-caine" local anaesthetics in 76 (90%) patients and recent administration of bupivacaine liposomal injectable suspension in eight (10%) patients. Twelve of the 84 (14%) procedures were performed with concomitant moderate sedation. Patient characteristics, procedural techniques, and clinical outcomes were reviewed. Early and delayed (30-day) complications were classified as either related to local diphenhydramine injection or to the procedure itself. Procedure-related complications were gradated using the Clavien-Dindo system.

RESULTS

Percutaneous biopsy was the most frequently performed procedure (57/84, 67%). Fifty-nine (70%) of the 84 procedures were ultrasound guided. The most common procedural site was the breast (34/84, 40%). All procedures were technically successful. There were two minor injection-related complications related to post-procedural pain. A single minor procedure-related complication involved a patient requiring hospital admission for post-renal biopsy related haematuria.

CONCLUSION

Injectable diphenhydramine appears to be a safe and effective local anaesthetic alternative in patients with "-caine" class contraindications undergoing radiology procedures. A future prospective trial would be useful to assess the safety profile in an large cohort of patients.

An analysis of post-operative pain and narcotic use following robotic assisted laparoscopic prostatectomy for same day discharge

Robotic assisted laparoscopic prostatectomy (RALP) has become the primary surgical modality in the treatment of prostate cancer. Most patients are discharged on postoperative day one. Same-day discharge is emerging as a potential new standard. We sought to establish factors correlating with post-operative pain after RALP procedures to design a same-day discharge protocol. We retrospectively reviewed 150 of recently performed RALP procedures from March 2020 to January 2021. Patient demographics and intra-operative variables were compared to Numeric Rating Scale (NRS) pain scores and total morphine milliequivalents (MME) at 2 h, 8 h, and averaged over the patient's admission post-operatively or first 48 h, whichever occurred first. We performed univariable and multivariable logistic regression to assess correlations with postoperative pain and narcotic use. NRS average > 3 or any MME given at 2 h postoperatively was significantly associated with continued post-operative pain averaged over admission (r_s = 0.32, 0.38, respectively; p < 0.001). MME given was also associated with longer operative time and negative related to body mass index. No other demographic data or intraoperative variables such as diabetes or pneumoperitoneum pressure were correlated with worsened post-operative pain scores > 3 or narcotic use. Local bupivacaine dose was also not associated with improved post-operative pain scores or narcotic use at 8 h (p = 0.98, 0.13). These findings suggest that patients with adequate postoperative pain control at 2 hours may be discharged same day from a pain control perspective. Further clinical evaluation regarding the role of local anesthetic use in RALPs is warranted.

A randomized controlled trial evaluating the effects of transversus abdominis plane block with compound lidocaine hydrochloride injection on postoperative pain and opioid consumption and gastrointestinal motility in patients undergoing gynecological laparotomy

Introduction

Incorporation of transversus abdominis plane (TAP) block into multimodal analgesia has been emphasized in Enhanced Recovery protocols (ERPs). However, benefit is limited in clinical practice. A potential explanation is the short duration of analgesia of standard local anesthetics. Herein, this randomized, double-blind, controlled trial evaluated whether TAPB with long-acting compound lidocaine hydrochloride injection reduces postoperative pain.

Methods

164 patients undergoing elective gynecological laparotomy under sevoflurane anesthesia randomly received ultrasound-guided TAP block with either saline, or ropivacaine, or compound lidocaine before anesthesia induction. The postoperative pain intensity (primary outcome) was evaluated by pain 11-point numerical rating scale. We also recorded sufentanil consumptions, time to first flatus, side-effects and hospital stay after surgery.

Results

We reported that pain scores at rest at postoperative 3h in group 0.375% ropivacaine was lower than that in group saline [mean 2.4 (SD 1.2) vs. 3.0 (1.0), p = 0.036]. Compared with saline, 0.4% and 0.6% compound lidocaine caused lower pain scores at rest at postoperative 12h [2.8 (0.9) vs. 2.1 (0.9) and 2.0 (0.9), p = 0.016 and p = 0.006]. Sufentanil usage for the first postoperative 48h was lower in group 0.6% compound lidocaine than group saline [24.2 (5.4) vs. 45.6 (7.5) µg, p  < 0.001]. Time to first flatus and hospital stay after surgery was shortest and the incidence of postoperative nausea was lowest in patients receiving 0.6% compound lidocaine.

Conclusion

TAP block with 0.6% compound lidocaine hydrochloride injection attenuates postoperative pain, reduces opioid consumption, accelerates gastrointestinal function recovery, and shortens length of hospital stay in patients after gynecological laparotomy.

Trial registration

ClinicalTrials.gov, identifier: NCT04938882.

Efficacy of Single Wound Infiltration With Bupivacaine and Adrenaline During Cesarean Delivery for Reduction of Postoperative Pain: A Randomized Clinical Trial

IMPORTANCE

Most women report moderate to severe pain after cesarean delivery. The extent of the ability of surgical wound infiltration with local anesthetic agents during cesarean delivery for the reduction of postoperative pain is uncertain.

OBJECTIVE

To examine the efficacy of single wound infiltration with bupivacaine and adrenaline during cesarean delivery for the reduction of postoperative pain.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted between January 25, 2018, and May 30, 2020, at a university teaching hospital in Afula, Israel. A total of 288 women with singleton pregnancy who were scheduled for a planned cesarean delivery at term were randomized to receive single wound infiltration with bupivacaine and adrenaline during cesarean delivery (intervention group) or no single wound infiltration (control group) at a 1:1 ratio.

INTERVENTIONS

In the intervention group, the subcutaneous layer was infiltrated on both sides of the wound by a mixture of bupivacaine and adrenaline before wound closure. Other perioperative techniques were similar between the groups.

MAIN OUTCOMES AND MEASURES

The primary outcome was mean pain intensity over the course of 24 hours after the operation, as measured by a visual analog scale (VAS) score ranging from 0 to 10 (with higher scores indicating greater pain intensity). To detect a mean (SD) reduction of 1 (3) points in the VAS score in the intervention group, 286 women were needed in total. Secondary outcomes included VAS score greater than 4 (indicating moderate pain) at 2 hours after the operation, use of rescue opioids, maternal satisfaction with the pain management procedure (using a scale of 1-5, with higher scores indicating greater satisfaction), duration of the operation, scar complications (hematoma, infection, and separation), and length of stay.

RESULTS

Among 288 women (mean [SD] age, 32.5 [5.1] years; all of Arab or Jewish ethnicity), 143 were randomized to the intervention group, and 145 were randomized to the control group. Demographic and obstetric variables were similar between groups. The primary outcome (VAS pain score) was significantly lower in the intervention group (mean [SD], 2.21 [0.56]) compared with the control group (mean [SD], 2.41 [0.73]; P = .02). In the intervention group, 11 women (7.7%) had a VAS score greater than 4 at 2 hours compared with 22 women (15.2%) in the control group (odds ratio, 0.47; 95% CI, 0.22-1.00; P = .05). In addition, compared with the control group, the intervention group had significantly lower postpartum use of rescue opioid analgesics (19 women [13.3%] vs 37 women [25.5%]; P = .009) and greater satisfaction with pain management (mean [SD] score, 4.65 [0.68] vs 4.44 [0.76]; P = .007). In the intervention vs control groups, duration of the operation, scar complications (hematoma, infection, or separation), and length of stay were comparable.

CONCLUSIONS AND RELEVANCE

In this study, wound infiltration with a single administration of bupivacaine and adrenaline during cesarean delivery reduced postoperative pain and opioid use and may have improved maternal satisfaction with pain management. These findings suggest the technique is efficacious, safe, and easy to perform.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03395912.

A Retrospective Comparison of Three Patient-Controlled Analgesic Strategies: Intravenous Opioid Analgesia Plus Abdominal Wall Nerve Blocks versus Epidural Analgesia versus Intravenous Opioid Analgesia Alone in Open Liver Surgery

Background: Adequate pain control is of crucial importance to patient recovery and satisfaction following abdominal surgeries. The optimal analgesia regimen remains controversial in liver resections. Methods: Three groups of patients undergoing open hepatectomies were retrospectively analyzed, reviewing intravenous patient-controlled analgesia (IV-PCA) versus IV-PCA in addition to bilateral rectus sheath and subcostal transversus abdominis plane nerve blocks (IV-PCA + NBs) versus patient-controlled thoracic epidural analgesia (TEA). Patient-reported pain scores and clinical data were extracted and correlated with the method of analgesia. Outcomes included total morphine consumption and numerical rating scale (NRS) at rest and on movement over the first three postoperative days, time to remove the nasogastric tube and urinary catheter, time to commence on fluid and soft diet, and length of hospital stay. Results: The TEA group required less morphine over the first three postoperative days than IV-PCA and IV-PCA + NBs groups (9.21 ± 4.91 mg, 83.53 ± 49.51 mg, and 64.17 ± 31.96 mg, respectively, p < 0.001). Even though no statistical difference was demonstrated in NRS scores on the first three postoperative days at rest and on movement, the IV-PCA group showed delayed removal of urinary catheter (removal on postoperative day 4.93 ± 5.08, 3.87 ± 1.31, and 3.70 ± 1.30, respectively) and prolonged length of hospital stay (discharged on postoperative day 12.71 ± 7.26, 11.79 ± 5.71, and 10.02 ± 4.52, respectively) as compared to IV-PCA + NBs and TEA groups. Conclusions: For postoperative pain management, it is expected that the TEA group required the least amount of opioid; however, IV-PCA + NBs and TEA demonstrated comparable postoperative outcomes, namely, the time to remove nasogastric tube/urinary catheter, to start the diet, and the length of hospital stay. IV-PCA with NBs could thus be a reliable analgesic modality for patients undergoing open liver resections.

Effect of Intraperitoneal Local Anesthetics in Laparoscopic Bariatric Surgery: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The effectiveness of intraperitoneal local anesthesia (IPLA) has been confirmed in other fields, but its use in bariatric surgery remains debatable. This study aimed to evaluate the analgesic effect of IPLA in bariatric surgery.

METHODS

PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to February 2022. All randomized controlled trials (RCTs) assessing IPLA's analgesic effect in bariatric surgery were included in this study. Pain-related indicators were the outcome.

RESULTS

Ten RCTs with 979 patients were included. Postoperative pain scores were significantly lower in IPLA group. Subgroup analysis demonstrated that IPLA was associated with lower pain scores in 6 h and at 24 h compared to the control group, without significant differences at 8, 12, and 48 h. Meanwhile, IPLA reduced the dose of opioids taken postoperatively. Additionally, there were no differences in adverse events between the two groups. As far as the number of postoperative analgesics used and hospital stays were concerned, our results did not show statistical differences between the two groups.

CONCLUSION

IPLA can reduce postoperative pain safely and effectively, particularly during the early postoperative stage.

Impact of Liposomal Bupivacaine on Post-Operative Pain and Opioid Usage in Thyroidectomy

OBJECTIVES

Opioid analgesia has been integral in post-operative pain control for decades. The over-prescription of opioids, commonly in the surgical patient, has contributed to the current opioid epidemic. Liposomal bupivacaine (LB), a long-acting analgesia formulation, has demonstrated decreased post-operative pain and opioid requirements in patients treated across multiple surgical subspecialties. The aims of this retrospective study are to assess post-operative pain and opioid use in patients who received LB at the time of thyroidectomy.

METHODS

A cohort-matched retrospective review of patients who underwent thyroidectomy by 2 surgeons between January 2010 and December 2019 was performed. Patients were divided into those that received LB intraoperatively and those that did not. Statistical analyses were performed using the Chi-square or Fisher's exact test, and 2-sample T-test or Wilcoxon rank sum test.

RESULTS

Of the 201 patients included in this study, 113 patients received LB and 88 did not. Patients who received LB had a lower median visual analog scale (VAS) pain score (2 vs 3, P = .2252), lower maximum VAS pain score (6 vs 7, P = .0898), were less likely to require opioid medications (73.5% vs 85.2%, P = .0434), and had a lower percentage of daily morphine milligram equivalent value ≥45 (89.8% vs 95.3%, P = .1581) during the post-operative period when compared to those that did not.

CONCLUSION

This study suggests a role for incisional infiltration with LB for post-operative pain management in patients undergoing transcervical thyroidectomy. We report reduced post-operative pain scores and opioid analgesia requirements in patients who received LB.

Ensuring the effectiveness and safety of peripheral blockades

Adequate analgesia determines the success of the performed surgical intervention. In modern surgery, most of postoperative complications are directly related to ineffective therapy of pain syndrome in the perioperative period. The main principle of modern analgesia is its multicomponence, when analgesia, neurovegetative blockade and relaxation are achieved and potentiated by different drugs and methods. The blockade of nociceptive impulses with a local anesthetic at the transmission stage provides effective, targeted analgesia, hyporefl exia and muscle relaxation, prevents the sensitization of neuroaxial structures, hyperalgesia and the development of postoperative chronic pain syndrome. At the same time, providing analgesia with drugs of central action leads to the ineffectiveness of therapy in 80 % of cases, which has serious consequences.The aim. According to the literature review, to evaluate the effectiveness and safety of peripheral blockades on the example of performing a blockade of the pterygopalatine ganglion.Conclusion. The pterygopalatine blockade has broad indications for use in ophthalmology, which is explained by the complex structure of the pterygopalatine ganglion and the possibility of simultaneous infl uence on sympathetic, parasympathetic and nociceptive innervation. All the presented methods of pterygopalatine blockade performance have their advantages and disadvantages. Ultrasound navigation eliminates technical difficulties and the possibility of damage of the pterygopalatine fossa anatomical structures, ensuring the effectiveness and safety of the pterygopalatine blockade.

Dexmedetomidine and levobupivacaine co-loaded, transcriptional transactivator peptide modified nanostructured lipid carriers or lipid-polymer hybrid nanoparticles, which performed better for local anesthetic therapy?

Local anesthetics (LAs) have been widely applied in clinic for regional anesthesia, postoperative analgesia, and management of acute and chronic pain. Nanostructured lipid carriers (NLCs) and lipid–polymer hybrid nanoparticles (LPNs) are reported as good choices for LA therapy. Transactivated transcriptional activator (TAT) was reported as a modifier for the topical delivery of drugs. In the present study, TAT modified, levobupivacaine (LEV) and dexmedetomidine (DEX) co-delivered NLCs (TAT-LEV&DEX-NLCs, T-L&D-N) and LPNs (TAT-LEV&DEX-LPNs, T-L&D-L) were designed and compared for the LA therapy. T-L&D-L exhibited better efficiency in improving the skin permeation, analgesic time, and pain control intensity than T-L&D-N both in vitro and in vivo. On the other side, T-L&D-N also improved the therapeutic effect of drugs to a large extent. These two systems both exhibited superiority in some respects. TAT modified LPNs are more promising platform for the long-term local anesthesia.

Discontinuation of the liposomal delivery of bupivacaine has no effect on pain management after primary total knee arthroplasty : no effect on pain scores, opioid consumption, or functional status

AIMS

Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes.

METHODS

On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function.

RESULTS

A total of 888 patients received Protocol 1 and while 789 received Protocol 2. The mean age of the patients was significantly higher in those who did not receive LB (66.80 vs 65.57 years, p = 0.006). The sex, BMI, American Society of Anesthesiologists physical status score, race, smoking status, marital status, operating time, length of stay, and discharge disposition were similar in the two groups. Compared with the LB group, discontinuing LB showed no significant difference in postoperative VRS pain scores up to 72 hours (p > 0.05), opioid administration up to 96 hours (p > 0.05), or AM-PAC scores within the first 24 hours (p > 0.05).

CONCLUSION

The control of pain after TKA with a multimodal management protocol is not improved by the addition of LB compared with traditional bupivacaine. Cite this article: Bone Joint J 2021;103-B(6 Supple A):102-107.

Discontinuation of Intraoperative Liposomal Bupivacaine in Primary THA Does Not Clinically Change Postoperative Subjective Pain, Opioid Consumption, or Objective Functional Status

BACKGROUND

There is debate regarding the benefit of liposomal bupivacaine (LB) as part of a periarticular injection (PAI) in total hip arthroplasty (THA). Here, we evaluate the effect of discontinuing intraoperative LB PAI on immediate postoperative subjective pain, opioid consumption, and objective functional outcomes.

METHODS

On July 1, 2019, an institutional policy discontinued the use of intraoperative LB PAI. A consecutive cohort that received LB PAI and a subsequent cohort that did not were compared. All patients received the same opioid-sparing protocol. Nursing documented verbal rating scale pain scores were averaged per patient per 12-hour interval. Opiate administration events were converted into morphine milligram equivalences per patient per 24-hour interval. The validated Activity Measure for Postacute Care (AM-PAC) tool was used to evaluate functional outcomes.

RESULTS

Six hundred thirty eight primary THAs received LB followed by 939 that did not. In the non-LB THAs, BMI was higher (30.06 vs 29.43; P < .05). Besides marital status, the remaining baseline demographics were similar between the two cohorts (P > .05). The non-LB THA cohort demonstrated a marginal increase in verbal rating scale pain scores between 12 to 24 hours (4.42 ± 1.70 vs 4.20 ± 1.87; P < .05) and 36 to 48 hours (4.49 ± 1.72 vs 4.21 ± 1.83; P < .05). There was no difference in inpatient opioid administration up to 96 hours postoperatively (P > .05) or AM-PAC functional scores within the first 24 hours (P > .05).

CONCLUSION

A small statistical, but not clinically meaningful, difference was observed in subjective pain scores with LB PAI discontinuation. Opioid consumption and postoperative AM-PAC functional scores were unchanged after LB PAI discontinuation.

Opioid-Free Recovery from Bunionectomy with HTX-011, a Dual-Acting Local Anesthetic Combining Bupivacaine and Meloxicam, as the Foundation of Non-Opioid Multimodal Analgesia

BACKGROUND

There is a need for postoperative pain control that minimizes or eliminates opioid use during the first 72 hours following surgery, when pain is most severe. HTX-011 is an extended-release, dual-acting local anesthetic that demonstrated superior 72-hour analgesia over standard of care bupivacaine hydrochloride (HCl) and saline placebo in a phase 3 bunionectomy study (EPOCH-1). Having shown HTX-011 monotherapy is superior to bupivacaine HCl in reducing postoperative pain intensity and opioid use, this follow-on study evaluated the safety and efficacy of HTX-011 as the foundation of a multimodal analgesia (MMA) regimen using over-the-counter medications recommended by practice guidelines for pain management.

METHODS

Following regional anesthesia administered as a lidocaine block, patients underwent unilateral bunionectomy with osteotomy and internal fixation. Prior to closure, HTX-011 (up to 60 mg bupivacaine/1.8 mg meloxicam) was applied without a needle. Patients received scheduled postoperative MMA alternating ibuprofen (600 mg) and acetaminophen (1 g) every 3 hours for 72 hours. Efficacy was assessed based on pain intensity (numeric rating scale [NRS; 0-10]) and consumption of opioid rescue medication (intravenous morphine milligram equivalents [MME]). Adverse event and vital sign monitoring, plus laboratory and wound healing assessments, were used to determine safety.

RESULTS

Over the 72-hour assessment period following bunionectomy, mean pain scores were mild in severity (NRS <4) and 22/31 patients (71%) experienced no severe pain (NRS ≥7) with HTX-011 as the foundation of scheduled, non-opioid MMA. Patients consumed an average of 1.61 MME total, with 24/31 (77%) requiring no opioid rescue medication (opioid-free). HTX-011 was well-tolerated and demonstrated no safety concerns with the inclusion of postoperative MMA.

CONCLUSIONS

HTX-011 as the foundation of an MMA regimen including scheduled ibuprofen and acetaminophen maintained mean postoperative pain scores in the mild range and enabled opioid-free recovery for 77% of bunionectomy patients through the 28-day recovery period.

A simple calculation of the maximum dose of the local anesthetic in pediatric dentistry with nomogram in Serbian

Clinicians should identify the risks associated with the use of anesthetics and understand the maximum recommended doses of local anesthetics. Errors in calculating the dose of local anesthetics are common due to the widespread use of these agents. Different methods of calculating the dose of the drug have different advantages and disadvantages, and no method can guarantee a calculation without errors. Nomogram is a simple graphical tool on which one can read the result of arithmetic operations with given numbers. The nomogram for calculating the maximum dose of local anesthetic enables quick cross-checking of the calculation, based on the patient's age or body weight. They are of special importance in the application of local anesthesia in children.

Serratus intercostal interfascial plane block in supraumbilical surgery: a prospective randomized comparison

BACKGROUND

Upper abdominal wall surgical incisions may lead to a severe postoperative pain. Therefore, adequate analgesia is important. Here we investigate whether the low serratus-intercostal interfascial plane block (SIPB) achieves an effective analgesia, considering opioids consumption, pain control and recovery quality in upper abdominal surgeries.

METHODS

This blinded, randomized controlled study was conducted on 102 patients undergoing open upper abdominal wall surgery under general anesthesia. All patients who received serratus-intercostal plane block at the eighth rib as analgesic technique were included in SIPB group and in control group those who received continuous intravenous morphine analgesia. Pain scores in numeric verbal scale (NVS) and opioids consumption at 0, 6, 12, 24 and 48 hours postoperatively were assessed. The quality of the postoperative recovery was evaluated using the QoR-15 questionnaire at 24 hours.

RESULTS

This study showed lower postoperative opioid consumption at 24 hours (P<0.0001; 4.17 mg vs. 41.52 mg of morphine) and better pain control (P<0.005) with mean pain scores (NVS 1.8±1.5 vs. 4.8±1.6) in group 0 (SIPB). The global QoR-15 scores 24 hours postoperatively were higher (better quality) in the SIPB group (122 vs. 100).

CONCLUSIONS

The low serratus-intercostal interfascial plane block (SIPB) provides efficient analgesia leading to a saving of opioids and improvement of the recovery quality in patients undergoing upper abdominal wall surgeries.

The 14-day repeated-dose toxicity study of a fixed-dose combination, QXOH/levobupivacaine, via subcutaneous injection in beagle dogs

QXOH-Levobupivacaine (LB) is a fixed-dose combination of 35-mM QXOH and 10-mM LB. It was developed for perioperative analgesia because of its long-acting analgesic effect. The purpose of this study was to evaluate the potential toxicity of QXOH-LB in beagle dogs in accordance with the Guidance on the repeated-dose toxicity published by the China Food and Drug Administration. Groups of five male and five female beagle dogs received normal saline, QXOH-LB (2, 4, and 8 mg/kg, calculated as QXOH), QXOH (2, 4, and 8 mg/kg), or LB (2 mg/kg, equals the concentration of LB in 8-mg/kg QXOH-LB group) at the volume of 1 mL/kg once per day for 14 days through subcutaneous injection. No mortality was observed. Dogs in the control group as well as animals treated with 2-mg/kg QXOH or QXOH-LB exhibited normal behaviors. Clinical signs of toxicity in dogs treated with 4 and 8 mg/kg of QXOH or QXOH-LB included decreased activity, unsteady gait, jerks, tremors, vocalization, emesis, ataxia, lateral/sternal recumbency, deep/rapid respiration, and gasping. Additionally, neurological function was found to be affected by QXOH and QXOH-LB at the doses of 4 and 8 mg/kg. All clinical signs were recovered within 24 h. The no-observed-adverse-effect level of QXOH and QXOH-LB was considered to be 2 mg/kg. Toxicokinetic data showed that exposure to QXOH and LB increased as QXOH-LB doses were increased from 4 to 8 mg/kg. There was no evidence of drug accumulation or any effect of gender.

Transversus Abdominis Plane Block With Liposomal Bupivacaine Versus Thoracic Epidural for Postoperative Analgesia After Deep Inferior Epigastric Artery Perforator Flap-Based Breast Reconstruction

PURPOSE

Autologous breast reconstruction with abdominally based free flaps has traditionally been associated with a longer hospital stay and higher initial cost relative to other reconstructive methods. One important component of this course is postoperative pain control. Thoracic epidural anesthesia is considered among the most effective methods for pain control in the immediate postoperative period following these procedures. Recently, our institution began using 4 quadrant transversus abdominis plane (TAP) blocks with liposomal bupivacaine. Encouraging trends were observed with utilization of TAP blocks; however, we sought to quantify this effect compared with that of thoracic epidural anesthesia. This study would contribute to a growing body of evidence supporting an enhanced recovery pathway for microvascular breast reconstruction.

METHOD

Thirty patients who underwent deep inferior epigastric artery perforator flap-based breast reconstruction from January 2016 to April 2017 were evaluated. Fifteen patients received thoracic epidural anesthesia, and 15 received 4 quadrant TAP blocks with liposomal bupivacaine. Opioid consumption was evaluated and compared for the first 3 days postoperatively. All opioids were converted to oral morphine equivalents (OMEs) for standardization. Day of discharge, day of Foley removal, and several traditionally opioid-related adverse effects were also recorded and compared.

RESULT

On postoperative days 0, 1, 2, and 3, opioid consumption among those given epidural anesthesia compared with those who received TAP blocks with liposomal bupivacaine was 34.9 versus 32.6 OMEs (P = 0.81), 98.9 versus 92.4 OMEs (P = 0.78), 59.7 versus 56.0 OMEs (P = 0.79), and 59.6 versus 24.5 OMEs (P = 0.005*), respectively. Total opioid consumption for the epidural group was 253.1 versus 205.4 OMEs for the TAP block group (P = 0.2743). Time until removal of Foley was 2.7 days for patients with an epidural and 2.1 days for those receiving TAP blocks (P = 0.0056*). Length of stay for those receiving epidural was 4.33 days compared with 3.53 days for those receiving TAP blocks (P = 0.0002*).

CONCLUSION

When using TAP blocks with liposomal bupivacaine, a statistically significant effect on postoperative day 3 and decreased opioid utilization overall were observed. Patients also had their Foley removed sooner and were discharged from the hospital earlier.

Intraoperative liposomal bupivacaine for skin graft donor site analgesia: A retrospective cohort study

INTRODUCTION

Burn injury and reconstructive operations often result in severe pain, particularly at skin graft donor sites. Traditional local anesthetics administered intraoperatively control pain at donor sites, but the duration of action is short. Liposomal bupivacaine, a novel local anesthetic, can provide sustained-release analgesia for 72h. The primary aim of this study was to describe the efficacy of liposomal bupivacaine for postoperative donor site pain control for patients undergoing skin graft procedures.

METHODS

A retrospective cohort study was performed on patients who received a donor site liposomal bupivacaine field block and was compared to a matched control. Patients rated donor site pain on post-operative day 0 and 1, and stated whether the donor or graft site was more painful.

RESULTS

Fifty-eight patients were included. Twenty-nine patients received liposomal bupivacaine. Eighty-six percent of patients in the treatment group rated donor site pain as three or less on postoperative day 0 and 1, compared to 3.4% in the control (p<0.0001). Also, 76% of patients in the treatment group stated donor site pain was less than graft site pain, compared to 3.4% in the control (p<0.0001).

CONCLUSION

Patients who received liposomal bupivacaine reported less postoperative donor site pain and found the donor site to be less bothersome without major complications. Liposomal bupivacaine may be a safe and promising agent for prolonging postoperative analgesia and minimizing donor site pain.

Retrospective Assessment of the Use of Liposomal Bupivacaine in Lumbar Fusions in Immediate Postoperative Hospital Care

BACKGROUND

Liposomal bupivacaine (LB) is approved by the U.S. Food and Drug Administration for administration into surgical sites for postsurgical analgesia. The liposomal formulation allows for sustained effects up to 72 hours.

METHODS

A retrospective study assessed patients undergoing lumbar interbody surgery. Visual analog scale pain scores and amount of opioids consumed were recorded at 12-hour intervals for 72 hours postoperatively, as were patterns of discharge and hospital length of stay (LOS).

RESULTS

A total of 122 patients (97 LB vs. 25 control group) were reviewed. Median LOS was shorter in the LB cohort compared with controls (1.94 vs. 3.08 days, respectively; P = 0.0043). When assessing the percentage of discharges between groups at 12-hour intervals, there were significantly more discharges in the LB cohort at 36-48 hours (P = 0.0226), and no differences elsewhere. There was a decrease in intravenous opioids consumed at 48-60 hours in the LB cohort compared with controls (P = 0.0494), a difference not detected at other time points or with oral or total opioids. Mean visual analog scale scores were significantly higher in the LB cohort compared with controls at 0-12 hours (5.2 vs. 3.9, respectively; P = 0.0079), but insignificantly different subsequently up to 72 hours. The LB cohort and controls were not significantly different in total amount of opioids consumed, overall pain scores, or regarding how the opioid amount consumed or pain scores changed over time.

CONCLUSIONS

The use of LB in lumbar interbody fusion decreases patients' LOS but has little effect on reducing overall pain scores or opioid use in the 72-hour postoperative hospital period.

Basics and Best Practices of Multimodal Pain Management for the Plastic Surgeon

Pain management is a central focus for the plastic surgeon’s perioperative planning, and it no longer represents a postoperative afterthought. Protocols that rely on opioid-only pain therapy are outdated and discouraged, as they do not achieve optimal pain relief, increase postoperative morbidity, and contribute to the growing opioid epidemic. A multimodal approach to pain management using non-opioid analgesic techniques is an integral component of enhanced recovery after surgery protocols. Careful perioperative planning for optimal pain management must be achieved in multidisciplinary collaboration with the perioperative care team including anesthesiology. This allows pain management interventions to occur at 3 critical opportunities—preoperative, intraoperative, and postoperative settings.

Comparison of preoperative versus postoperative transversus abdominis plane and rectus sheath block in patients undergoing minimally invasive colorectal surgery

AIM

Ultrasound-guided transversus abdominis plane and rectus sheath block (TAPRSB) decreases pain scores and narcotic use postoperatively after colorectal surgery (CRS). It is unclear if the effectiveness of TAPRSB varies according to whether it is performed preoperatively or postoperatively. Our aim was to investigate this.

METHOD

We compared patients who underwent preoperative TAPRSB or postoperative TAPRSB during minimally invasive CRS. Primary end-points were pain scores and oral morphine milligram equivalent (MME) use postoperatively. Secondary end-points included perioperative factors affecting pain scores and postoperative MME. Summary statistics and univariate analysis by nonparametric tests were utilized. The mixed-effect model was applied to model the repeatedly measured pain score.

RESULTS

From April 2015 until May 2018 168 patients received TAPRSB before (115) or after (53) minimally invasive CRS. The cohort included 79 (47.0%) women, and had an average age of 59.11 (±12.32) years and mean body mass index of 28.32 (±5.82) kg/m² . Indication for surgery was cancer in 66 (39.3%), polyp in 43 (25.6%) and diverticulitis in 43 (25.6%). Right colectomy was performed in 61 (36.3%), low anterior resection in 46 (27.4%) and sigmoid colectomy in 40 (23.8%) patients. The demographics of the groups were similar. Postoperative TAPRSB was only associated with lower pain scores at 12 h postoperatively. As secondary outcomes, average pain scores and MME were lower in patients who were older, had right colectomy or intracorporeal anastomosis.

CONCLUSIONS

Postoperative TAPRSB resulted in lower pain scores than preoperative TAPRSB 12 h after minimally invasive CRS, but otherwise no differences were seen in pain scores or MME use.

In vitro and in vivo studies of micro-depots using tailored microemulsion for sustained local anaesthesia

In clinical practice, lidocaine is used as local anesthetic for the management of post-operative pain. The commercial formulation including gels, injections and ointments showed short duration of action (1 to 2 h). In this paper, the efforts have being made to develop tailored lidocaine-microemulsion (o/w), which on penetration in the skin layer cause micro-depots formation due to destabilization of the microemulsion system. To identify the microemulsion region, pseudo ternary diagrams were constructed using Capmul MCM as oil, Pluronic F68 as tri-block surfactant, polyethylene glycol 200 as co-surfactant at 1:4 and 1:6 ratios (S:Co-S). The selected 5%w/v lidocaine loaded microemulsion [Ld-ME-2(1:4)] was stable in thermodynamic test and during shelf life period (3 months). In ex vivo permeability study, the lidocaine release from Ld-ME-2(1:4) microemulsion was sustained in comparison to the marketed lidocaine ointment. The skin irritation study confirmed the safety of lidocaine loaded microemulsion. Tail flick test showed improved and sustain local anaesthetic effect in comparison to the market ointment. The improved efficacy of microemulsion system, was due to high penetration in the skin layer due to local precipitation of lidocaine from microemulsion. The findings suggest that the tailored microemulsion could be a potential strategy to prolong the local anaesthesia.

Sucrose Acetate Isobutyrate as an In situ Forming Implant for Sustained Release of Local Anesthetics

OBJECTIVE

In this study, an injectable Sucrose Acetate Isobutyrate (SAIB) drug delivery system (SADS) was designed and fabricated for the sustained release of Ropivacaine (RP) to prolong the duration of local anesthesia.

METHODS

By mixing SAIB, RP, and N-methyl-2-pyrrolidone, the SADS was prepared in a sol state with low viscosity before injection. After subcutaneous injection, the pre-gel solution underwent gelation in situ to form a drug-released depot.

RESULT

The in vitro release profiles and in vivo pharmacokinetic analysis indicated that RP-SADS had suitable controlled release properties. Particularly, the RP-SADS significantly reduced the initial burst release after subcutaneous injection in rats.

CONCLUSION

In a pharmacodynamic analysis of rats, the duration of nerve blockade was prolonged by over 3-fold for the RP-SADS formulation compared to RP solution. Additionally, RP-SADS showed good biocompatibility in vitro and in vivo. Thus, the SADS-based depot technology is a safe drug delivery strategy for the sustained release of local anesthetics with long-term analgesia effects.

Local Infiltration Analgesia With Liposomal Bupivacaine Improves Early Outcomes After Total Knee Arthroplasty: 24-Hour Data From the PILLAR Study

BACKGROUND

Enhanced postoperative care pathways have shifted total knee arthroplasty (TKA) to outpatient and short-stay settings, placing greater emphasis on predischarge outcomes. In this study, we report prespecified secondary and tertiary end points of the PILLAR study within 24 hours after TKA in patients receiving local infiltration analgesia (LIA) with or without liposomal bupivacaine (LB).

METHODS

Patients with knee osteoarthritis were randomized 1:1 to receive LIA with LB 266 mg/20 mL admixed with bupivacaine HCl 0.5% 20 mL (n = 70) or bupivacaine HCl alone (n = 69). End points (0-24 hours postsurgery) were proportion of opioid-free patients, opioid consumption, areas under the curve of visual analog scale pain intensity scores, patient satisfaction, discharge readiness, and ambulation. Safety was also assessed.

RESULTS

Patients receiving LIA with LB were 16% less likely to require opioid rescue within 24 hours postsurgery (17.1% vs 1.4%; relative risk, 0.085; 95% confidence interval, 0.011-0.633). LIA with LB was associated with a 91% reduction in opioid consumption (P = .0009) and 19% reduction in pain intensity (P = .0142). Significantly more patients receiving LB were discharge ready (42.9% vs 27.5%; P = .0449) and satisfied with pain treatment (84.6% vs 69.2%; P = .0306). A numerically lower but not significantly different proportion achieved steady gait/no dizziness with LIA with LB (42.9% vs 52.2%). Adverse event incidence was similar between groups.

CONCLUSION

LIA with LB 266 mg plus bupivacaine HCl significantly reduced opioid requirements and pain intensity and significantly improved discharge readiness and satisfaction 0-24 hours after TKA compared with bupivacaine HCl alone. These findings support the use of LIA with LB for TKA when early discharge is the goal.

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.

Citrem–phosphatidylcholine nano-self-assemblies: solubilization of bupivacaine and its role in triggering a colloidal transition from vesicles to cubosomes and hexosomes

In concentration- and lipid composition-dependent manners, bupivacaine triggers lamellar–nonlamellar phase transitions in citrem/soy phosphatidylcholine nanodispersions.

In vitro and in vivo quantification of chloroprocaine release from an implantable device in a piglet postoperative pain model

Background

The pharmacokinetic properties and clinical advantages of the local anesthetic chloroprocaine are well known. Here, we studied the pharmacokinetic profile of a new hydrogel device loaded with chloroprocaine to investigate the potential advantages of this new strategy for postoperative pain (POP) relief.

Materials and methods

We performed both in vitro and in vivo analyses by considering plasma samples of four piglets receiving slow-release chloroprocaine. To quantify chloroprocaine and its inactive metabolite 4-amino-2-chlorobenzoic acid (ACBA), a HPLC–tandem mass spectrometry (HPLC-MS/MS) analytical method was used. Serial blood samples were collected over 108 hours, according to the exposure time to the device.

Results

Chloroprocaine was consistently found to be below the lower limit of quantification, even though a well-defined peak was observed in every chromatogram at an unexpected retention time. Concerning ACBA, we found detectable plasma concentrations between T₀ and T_12h, with a maximum plasma concentration (C_max) observed 3 hours after the device application. In the in vitro analyses, the nanogel remained in contact with plasma at 37°C for 90 minutes, 3 hours, 1 day, and 7 days. Chloroprocaine C_max was identified 1 day following exposure and C_min after 7 days, respectively. Additionally, ACBA reached the C_max following 7 days of exposure.

Conclusion

A thorough review of the literature indicates that this is the first study analyzing both in vivo and in vitro pharmacokinetic profiles of a chloroprocaine hydrogel device and is considered as a pilot study on the feasibility of including this approach to the management of POP.

Extended Release Liposomal Bupivacaine Injection (Exparel) for Early Postoperative Pain Control Following Palatoplasty

INTRODUCTION

Liposomal bupivacaine (LB) is a long-acting local anesthetic reported to decrease postoperative pain in adults. The authors demonstrate the safe use of LB in pediatric patients with improved pain control following palatoplasty.

MATERIALS AND METHODS

Retrospective patient series of all single-surgeon palatoplasty patients treated at a tertiary craniofacial center from August 2014 to December 2015 were included. All patients received 1.3% LB intraoperatively as greater palatal nerve and surgical field blocks in 2-flap V-Y pushback palatoplasty. Postoperative oral intake, opioids administered, duration of hospitalization, and FLACC (face, legs, activity, cry, consolability) pain scores were measured.

RESULTS

Twenty-seven patients (16 males and 11 females, average age of 10.8 months, weight 8.8 kg) received 2.9 ± 0.9 mL (2.6 ± 1.9 mg/kg) 1.3% LB. Average FLACC scores were 2.4 ± 2.2/10 in the postanesthesia care unit and 3.8 ± 1.8/10 while inpatients. Oral intake was first tolerated 10.3 ± 11.5 hours postoperatively and tolerated 496.4 ± 354.2 mL orally in the first 24 hours postoperatively. Patients received 8.5 ± 8.4 mg hydrocodone equivalents (0.46 ± 0.45 mg/kg per d hydrocodone equivalents) and were discharged 2.1 ± 1.3 days postoperatively. Opioid-related adverse events included emesis in 7.4% and pruritis in 3.7% of patients.

CONCLUSIONS

The LB may be used safely in pediatric patients. Intraoperative injection of LB during palatoplasty can yield low postoperative opioid use and an early and adequate volume of oral intake over an average hospital stay. Further cost-efficacy studies of LB are needed to assess its value in pediatric plastic surgery.

Delivery systems of local anesthetics in bone surgery: are they efficient and safe?

Management of postoperative pain following bone surgery includes administration of local anesthetics (LAs). Smart delivery systems, including triggered systems, have been designed to provide a continuous release of LA in situ. However, these systems can provide a high level of LA locally. This review will examine the state-of-the-art regarding the LA delivery systems optimized for management of postoperative pain in bone surgery and will discuss the potential adverse effects of LAs on the overall pathways of bone healing, including the inflammation response phase, hemostasis phase, tissue repair phase and remodeling phase. There is a clinical need to document these effects and the potential impacts on the clinical outcome of the patient.

Local Anesthetic Systemic Toxicity

Local anesthetics are commonly used in the perioperative environment to facilitate surgical procedures or to provide postoperative pain management for patients. The use of local anesthetics, however, introduces the risk of complications resulting from local anesthetic systemic toxicity and the risks of increased morbidity and mortality for the surgical patient. Systemic toxicity from the injection or overdose of local anesthetics is a rare but potentially fatal complication that occurs in less than 1 in 1,000 patients. This article provides the perioperative nurse with information about local anesthetics, the signs and symptoms of local anesthetic systemic toxicity, and the information needed to manage a patient experiencing this complication.

Opiate-Free Pain Therapy Using Carbamazepine-Loaded Microparticles Provides Up to 2 Weeks of Pain Relief in a Neuropathic Pain Model

INTRODUCTION

Opioids remain a mainstay in the treatment of acute and chronic pain, despite numerous and potentially dangerous side effects. There is a great unmet medical need for alternative treatments for patients suffering from pain that do not result in addiction or adverse side effects. Anticonvulsants have been shown to be effective in managing pain, though high systemic levels and subsequent side effects limit their widespread usage. Our goal was to determine if the incorporation of an anticonvulsant, carbamazepine, into a biodegradable microparticle for local sustained perineural release would be an efficacious analgesic following a peripheral injury.

METHODS

Following induction of the chronic constriction injury model in Sprague-Dawley rats, mechanical allodynia testing was performed using von Frey filaments and thermal allodynia was evaluated using the Hargreaves method. Histology and blood work were performed to evaluate toxicity as well as to monitor drug and metabolite presence over time.

RESULTS

A 2-fold increase in hindpaw withdrawal thresholds in animals receiving carbamazepine-loaded microparticles relative to controls was observed for up to 14 days after treatment. Drug and metabolite had a peak blood concentration of 54.7 ng/mL and dropped off exponentially to < 5 ng/mL over a few days.

CONCLUSION

This formulation reduced systemic exposure to carbamazepine over 1,000-fold relative to traditional analgesic dosing regimens. This 2-component drug delivery system has been specifically engineered to release a controlled amount of carbamazepine over a 14-day period, providing significant pain relief with no toxicological or observable adverse events via behavioral or histochemical analysis.

Liposomal Bupivacaine Use in Third Molar Impaction Surgery: INNOVATE Study

The analgesic efficacy and safety of liposomal bupivacaine (LB) in third molar extraction was evaluated in this phase 3, double-blind, placebo-controlled study of subjects undergoing bilateral third molar extraction. Subjects were randomized 2 : 1 to infiltration with LB (133 mg/10 mL) or placebo, and received opioid rescue medication as needed. Primary efficacy measure was cumulative area under the curve (AUC) of numeric rating scale (NRS) pain severity scores through 48 hours (AUC of NRS_0-48) postsurgery. Other measures included AUC of NRS_0-24, AUC of NRS_0-72, and AUC of NRS_0-96, and incidence of adverse events. There were 150 subjects in the primary efficacy population (n = 99 LB, n = 51 placebo) and 89 in the per-protocol population (n = 59 LB, n = 30 placebo). Least-squares mean for AUC of NRS_0-48 was 172.3 LB versus 194.7 placebo (P = .227) in the primary efficacy population and 120.8 LB versus 183.3 placebo (P = .023) in the per-protocol population. At all time points, between-group differences in AUC of NRS scores were significant in the per-protocol population (LB lower than placebo, P < .05) but not in the primary efficacy population. The adverse event profile was similar between groups. LB produced significantly lower cumulative pain scores versus placebo at all time points in the per-protocol analysis but not in the primary efficacy analysis because of protocol violations. This study indicates significant improvement in pain scores in the third molar model, but because of extensive protocol violations additional studies are warranted to demonstrate effectiveness.

Utility of anesthetic block for endometrial ablation pain: a randomized controlled trial

BACKGROUND

Second-generation endometrial ablation has been demonstrated safe for abnormal uterine bleeding treatment, in premenopausal women who have completed childbearing, in short-stay surgical centers and in physicians' offices. However, no standard regarding anesthesia exists, and practice varies depending on physician or patient preference and hospital policy and setting.

OBJECTIVE

The aim of this study was to evaluate whether local anesthetic, in combination with general anesthesia, affects postoperative pain and associated narcotic use following endometrial ablation.

MATERIALS AND METHODS

This was a single-center single-blind randomized controlled trial conducted in an academic-affiliated community hospital. A total of 84 English-speaking premenopausal women, aged 30 to 55 years, who were undergoing outpatient endometrial ablation for benign disease were randomized to receive standardized paracervical injection of 20 mL 0.25% bupivacaine (treatment group) or 20 mL normal saline solution (control group) upon completion of ablation. The study was designed to test a 40% 1-hour mean visual analog scale (VAS) pain score difference with an average standard deviation of 75% of both groups' mean VAS scores, using a 2-tailed test, a type I error of 5%, and statistical power of 80%. A sample of 36 patients per study group was required. Assuming a 15% attrition rate, the study enrolled 42 patients per study arm randomized in blocks of 2 (84 total). Two-tailed cross-tabulations with Fisher exact significance values where appropriate and Student t tests were used to compare patient characteristics. Backward stepwise regressions were conducted to control for confounding.

RESULTS

Between April 2016 and February 2017, a total of 108 women scheduled for endometrial ablation were screened (refusals, n = 21; ineligible, n = 3) to determine whether there were meaningful differences in postoperative VAS pain scores and postoperative narcotic use. Of the 84 randomized women, 2 age-ineligible women were excluded. Intent-to-treat analyses included 1 incorrect randomization (in which the provider consciously decided to provide analgesia regardless of the protocol, after which the provider was excluded from further study participation) and 3 women having no ablation because of operative difficulties. Three were lost to second-day follow-up. Treatment group patients (n = 41) experienced 1.3 points lower 1-hour postoperative VAS pain scores than the control group (n = 41, P = .02). The difference diminished by 4 hours (P = .31) and was negligible by 8 hours (P = .62). Treatment group patients used 3.6 less morphine equivalents of postoperative pain medication (P = .05). Regression analyses controlled for confounding reduced the 1-hour postoperative treatment group pain score difference to 0.8 (confidence interval [CI], -0.6 to 0.1) but slightly increased the average postoperative morphine equivalents to 3.7 (CI, -6.8 to -0.7).

CONCLUSION

This randomized controlled trial found that local anesthetic with low risk for complications, used in conjunction with general anesthesia, decreased postoperative pain at 1 hour and significantly reduced postoperative narcotic use following endometrial ablation. Further research is needed to determine whether the study results are generalizable and whether post procedure is the best time to administer the paracervical block to decrease endometrial ablation pain.

Liposomal bupivacaine for the management of postsurgical donor site pain in patients with burn injuries: a case series from two institutions

Donor site pain associated with skin graft procedures is frequently intense and difficult to treat. Liposomal bupivacaine, a prolonged‐release local anesthetic indicated for single‐dose administration to produce postsurgical analgesia, may be a viable option in managing donor site pain.

Enhanced Triggering of Local Anesthetic Particles by Photosensitization and Photothermal Effect Using a Common Wavelength

On-demand pain relief systems would be very helpful additions to the armamentarium of pain management. Near-infrared triggered drug delivery systems have demonstrated the potential to provide such care. However, challenges remain in making such systems as stimulus-sensitive as possible, to enhance depth of tissue penetration, repeatability of triggering, and safety. Here we developed liposomes containing the local anesthetic tetrodotoxin and also containing a photosensitizer and gold nanorods that were excitable at the same near-infrared wavelength. The combination of triggering mechanisms enhanced the photosensitivity and repeatability of the system in vitro when compared with liposomes with a single photoresponsive component. In vivo, on-demand local anesthesia could be induced with a low irradiance and short irradiation duration, and liposomes containing both photosensitizer and gold nanorods were more effective than those containing just one photoresponsive component. Tissue reaction was benign.

Liposomal Bupivacaine May Benefit Select Reduction Mammaplasty Patients

BACKGROUND

Postoperative pain control can be challenging in reduction mammaplasty patients. This study compares perioperative liposomal bupivacaine (Exparel; Pacira Pharmaceuticals, Inc, San Diego, Calif) with standard local anesthetics to determine if liposomal bupivacaine decreases opioid and antiemetic use, impacting length of stay and complication rates, thus improving patient outcomes.

METHODS

A retrospective review of 170 reduction mammaplasty patients was performed. Patients were divided into groups based on local anesthetic used (bupivacaine only and liposomal bupivacaine) and into subgroups based on obesity classification. Length of hospital stay; pain scores immediately postoperatively, at discharge, and at follow-up; and postoperative analgesics and antiemetics were compared. Further analysis was performed after weight stratification within pre- and postmenopausal categories.

RESULTS

Liposomal bupivacaine resulted in less pain than bupivacaine immediately postoperatively and at discharge in obesity class I (P = 0.021 and P = 0.018). In obesity class II, antiemetic use was lower in the liposomal bupivacaine group (P = 0.012). Length of stay was persistently lower with liposomal bupivacaine for premenopausal women, and this difference was significant in obesity class I (P = 0.038). In premenopausal women, discharge pain scores were lower in the overweight liposomal bupivacaine group (P = 0.034) and analgesic use was lower in obesity class III (P = 0.004).

CONCLUSIONS

Liposomal bupivacaine decreases postoperative pain, opioid, and antiemetic use in select patients. Liposomal bupivacaine might not be equally efficacious in pain reduction in obese or postmenopausal women given the theoretical increased absorption by adipose tissue. In addition, liposomal bupivacaine may have a dose-dependent effect, and weight-based dosing should be investigated.

Multimodal Pain Management for Enhanced Recovery: Reinforcing the Shift From Traditional Pathways Through Nurse-Led Interventions

Despite recent advances in perioperative patient care, postsurgical pain continues to be undermanaged. There is increasing acceptance of the concept that effective postsurgical pain management is best achieved through combined use of more than one analgesic agent or technique, and overreliance on opioids produces unwanted side effects limiting their utility. Accordingly, a balanced, multimodal approach to pain management within the larger framework of an Enhanced Recovery After Surgery (ERAS) pathway has become standard at many institutions for perioperative care, to control postsurgical pain, reduce opioid-related adverse events, hasten postsurgical recovery, and shorten length of hospital stay. The success of ERAS is dependent on nurses and the multidisciplinary team to execute its standardized processes across the care continuum, including patient education, perioperative care, and postsurgical evaluation. Here, we review current concepts related to multimodal analgesia and ERAS regarding care of adult surgical patients and discuss the perioperative nurse's role within this paradigm.

Local infiltration for postsurgical analgesia following total hip arthroplasty: a comparison of liposomal bupivacaine to traditional bupivacaine

OBJECTIVE

To assess postsurgical clinical and economic outcomes of patients who received local infiltration containing liposomal bupivacaine versus traditional bupivacaine for pain management following total hip arthroplasty (THA).

METHODS

This retrospective study included two groups of consecutive patients undergoing THA. The experimental group received local infiltration with a combination of liposomal bupivacaine, bupivacaine HCl 0.25% with epinephrine 1:200,000, and ketorolac for postsurgical analgesia. The historical control group received the previous standard of care: local infiltration with a combination of bupivacaine HCl 0.25% with epinephrine 1:200,000 and ketorolac. Key outcomes included distance walked, length of stay (LOS), opioid medication use, numeric pain scores, hospital charges, hospital costs, all-cause 30 day readmission rate, and adverse events (AEs). Both unadjusted and adjusted (i.e. age, sex, insurance type, living situation, body mass index, procedure side, and comorbidity) outcomes were compared between the two groups.

RESULTS

The experimental group (n = 64) demonstrated statistically significant improvement versus the historical control group (n = 66) in mean distance walked on discharge day (249.2 vs. 180.0 feet; unadjusted p = .025, adjusted p = .070), mean LOS (2.0 vs. 2.7 days; p < .001, p = .002), proportion of patients who used opioid rescue medication on postoperative day (POD) 1 (29.7% vs. 56.1%; p = .002, p = .003) and POD 2 (7.8% vs. 30.3%; p = .001, p = .003), mean cumulative area under the curve for pain score on POD 0 (127.6 vs. 292.5; p < .001, both), POD 1 (92.9 vs. 185.0; p < .001, both), and POD 2 (93.8 vs. 213.8; p = .006, both). Among a subgroup of patients with available financial information, mean hospital charges were lower in the experimental group ($43,794 [n = 24] vs. $48,010 [n = 66]; p < .001, both). Rates of all-cause 30 day readmission and AEs were not significantly different between groups. No falls occurred.

CONCLUSIONS

Infiltration at the surgical site with liposomal bupivacaine was associated with improved postsurgical outcomes when compared with traditional bupivacaine in patients undergoing THA.

Liposomal bupivacaine versus traditional bupivacaine for pain control after total hip arthroplasty: A meta-analysis

BACKGROUND

In the past, the efficacy of local infiltration of liposomal bupivacaine for total hip arthroplasty (THA) patients was in debate. Therefore, this meta-analysis was conducted to determine whether local infiltration of liposomal bupivacaine provides better pain relief after THA.

METHODS

We searched Web of Science, PubMed, Embase, and the Cochrane Library databases to the April 2017. Any studies comparing liposomal bupivacaine and traditional bupivacaine were included in our meta-analysis. The outcomes included visual analog scale (VAS) at 24, 48, and 72 hours, total morphine consumption at 24 hours, and the length of hospital stay. We assessed the pooled data using a random-effect model.

RESULTS

Six studies were finally included in this meta-analysis. Our pooled data analysis demonstrated that liposomal bupivacaine was more effective than the traditional bupivacaine in terms of VAS at 24 hours (P  =  .018) and the length of hospital stay (P  =  .000). There was no significant difference in terms of the VAS at 48 and 72 hours and total morphine consumption at 24 hours (P >.05).

CONCLUSION

Compared with the traditional bupivacaine, liposomal bupivacaine shows better pain control at 24 hours and reduces the length of hospital stay after THA. Its economic costs must be assessed in multimodal center randomized controlled trials when being recommended as a long-acting alternative analgesic agent for a THA patient.

Systematic Review of Liposomal Bupivacaine (Exparel) for Postoperative Analgesia

BACKGROUND

Management of postoperative pain often requires multimodal approaches. Suboptimal dosages of current therapies can leave patients experiencing periods of insufficient analgesia, often requiring rescue therapy. With absence of a validated and standardized approach to pain management, further refinement of treatment protocols and targeted therapeutics is needed. Liposomal bupivacaine (Exparel) is a longer acting form of traditional bupivacaine that delivers the drug by means of a multivesicular liposomal system. The effectiveness of liposomal bupivacaine has not been systematically analyzed relative to conventional treatments in plastic surgery.

METHODS

A comprehensive literature search of the MEDLINE, PubMed, and Google Scholar databases was conducted for studies published through October of 2015 with search terms related to liposomal bupivacaine and filtered for relevance to postoperative pain control in plastic surgery. Data on techniques, outcomes, complications, and patient satisfaction were collected.

RESULTS

A total of eight articles were selected and reviewed from 160 identified. Articles covered a variety of techniques using liposomal bupivacaine for postoperative pain management. Four hundred five patients underwent procedures (including breast reconstruction, augmentation mammaplasty, abdominal wall reconstruction, mastectomy, and abdominoplasty) where pain was managed with liposomal bupivacaine and compared with those receiving traditional pain management. Liposomal bupivacaine use showed adequate safety and tolerability and, compared to traditional protocols, was equivalent or more effective in postoperative pain management.

CONCLUSION

Liposomal bupivacaine is a safe method for postoperative pain control in the setting of plastic surgery and may represent an alternative to more invasive pain management systems such as patient-controlled analgesia, epidurals, peripheral nerve catheters, or intravenous narcotics.

Concept of the Ambulatory Pain Physician

PURPOSE OF REVIEW

Given the growing number of ambulatory surgeries being performed and the variability in postoperative pain requirements, early discharge, and inconsistent follow-up, ambulatory surgery presents a unique challenge for this patient population and warrants the presence of an ambulatory pain specialist to evaluate a patient preoperatively and postoperatively to optimize patient safety and satisfaction. This article explores the crucial role that a dedicated pain physician would have in the ambulatory surgery setting.

RECENT FINDINGS

The prevalence of chronic pain, opioid use, and substance abuse is growing in this country, while ambulatory and same-day surgery have also experienced considerable growth. Inevitably, more patients with challenging chronic pain or substance abuse are having ambulatory surgery. Increased BMI, advanced age, more comorbidities warranting a higher ASA physical status classification, and longer surgeries are now all components of ambulatory surgery that contribute to increased risk too. Certain surgeries including breast surgery, inguinal hernia repair, and thoracotomy are at higher risk for the conversion of acute to chronic pain, and an ambulatory pain specialist would be beneficial for added focus on these patients. Multimodal pain control with non-opioids and regional anesthesia adjuvants are beneficial, while emphasis on a patient's functional capacity may be more useful than quantifying the severity of pain. Despite the best efforts of patients' primary care providers or surgeons, patients often are discharged with more chronic opioid therapy than they presented with, and an ambulatory pain specialist can help manage the complications and prevent further escalation of this opioid epidemic. An onsite anesthesiologist with interest in pain management in each ambulatory surgery center administering anesthesia and available onsite to deal with immediate preoperative, intraoperative, and recovery room would be ideal to curb and manage complication from uncontrolled pain and related pain issues.

Could the Use of an Enhanced Recovery Protocol in Laparoscopic Donor Nephrectomy be an Incentive for Live Kidney Donation?

Introduction and Background: Gastrointestinal (GI) recovery after major abdominal surgery can be delayed from an ongoing need for narcotic analgesia thereby prolonging hospitalization. Enhanced recovery after surgery (ERAS) is a multimodal perioperative care pathway designed to facilitate early recovery after major surgery by maintaining preoperative body composition and physiological organ function and modifying the stress response induced by surgical exposure. Enhanced recovery programs (ERPs) in colorectal surgery have decreased the duration of postoperative ileus and the hospital stay while showing equivalent morbidity, mortality, and readmission rates in comparison to the traditional standard of care. This study is a pilot trial to evaluate the benefits of ERAS protocols in living kidney donors undergoing laparoscopic nephrectomy.

Methods: This is a single-center, non-randomized, retrospective analysis comparing the outcomes of the first 40 live kidney donors subjected to laparoscopic nephrectomy under the ERAS protocol to 40 donors operated prior to ERAS with traditional standard of care. Our ERAS protocol includes reduced duration of fasting with preoperative carbohydrate loading, intraoperative fluid restriction to 3 ml/kg/hr, target urine output of 0.5 ml/kg/hr, use of subfascial Exparel injection (bupivacaine liposome suspension), and postoperative narcotic-free pain regimen with acetaminophen, ketorolac, or tramadol. Short-term patient outcomes were compared using Pearsons’s Chi-Squared test for categorical variables and the Kruskal-Wallis test for continuous variables. Additionally, a multivariate analysis was conducted to evaluate factors influencing patient length of stay and likelihood of readmission.

Results: ERAS protocol reduced the postoperative median length of stay decreased from 2.0 to 1.0 days (p=0.001). Overall pain scores were significantly lower in the ERAS group (peak pain score 6.0 vs. 8.00, p< 0.001; morning after surgery pain score 3.0 vs. 7.0, p=0.001; lowest pain score 0.0 vs. 2.0, p=0.016) despite the absence of postoperative narcotics. The average duration of surgery was shorter in the ERAS group (248 vs. 304 minutes, p<0.001). The average amount of intraoperative fluid used was significantly lower in the ERAS group (2500 ml vs. 3525 ml, p<0.001) without affecting the donor renal function. The incidence of delayed graft function was similar in the two groups (p=0.541). A trend toward lower readmission was noted with the ERAS protocol (12.8% vs. 27.5%, p=0.105). GI dysfunction was the most common reason for readmission.

Conclusion: Application of an ERAS protocol in a laparoscopic living donor nephrectomy was associated with reduced length of hospitalization and improved pain scores related likely to intraoperative use of subfascial Exparel and a shorter duration of ileus. Restricted use of intraoperative fluids prevents excessive third spacing and bowel edema, enhancing gut recovery without adversely impacting recipient graft function. This study suggests that ERAS has the potential to enhance the advantages of laparoscopic surgery for live kidney donation through optimizing donor outcomes and perioperative patient satisfaction.

Understanding of anesthesia - Why consciousness is essential for life and not based on genes

Anesthesia and consciousness represent 2 mysteries not only for biology but also for physics and philosophy. Although anesthesia was introduced to medicine more than 160 y ago, our understanding of how it works still remains a mystery. The most prevalent view is that the human brain and its neurons are necessary to impose the effects of anesthetics. However, the fact is that all life can be anesthesized. Numerous theories have been generated trying to explain the major impact of anesthetics on our human-specific consciousness; switching it off so rapidly, but no single theory resolves this enduring mystery. The speed of anesthetic actions precludes any direct involvement of genes. Lipid bilayers, cellular membranes, and critical proteins emerge as the most probable primary targets of anesthetics. Recent findings suggest, rather surprisingly, that physical forces underlie both the anesthetic actions on living organisms as well as on consciousness in general.