Pain and Opioid use Following Total Knee Arthroplasty: Psycho-Social Factors are More Predictive Than Pharmacogenomics.

BACKGROUND: This prospective, observational study was designed to assess the phenotype variation of the genes associated with pain and opioid use following total knee arthroplasty (TKA) in comparison to psycho-social elements. METHODS: Preoperative demographic data and Patient-Reported Outcomes Measurement Information System-43 scores were obtained on 305 elective TKA patients. Patient visual analog scale pain scores and opioid use were extracted from the hospital record. Following discharge, participants completed a daily log of visual analog scale pain score, and medications used over 30 days. Pharmacogenomic testing was performed for three genes, CYP2D6, COMT, and OPRM1, which are involved in the opioid pathway and pain modulation. RESULTS: Other than increased pain seen in the COMT high activity group while in the hospital, none of the phenotype variations of the three genes were significantly associated with the participants' pain or opioid use. The Patient-Reported Outcomes Measurement Information System-43 domains of pain interference and anxiety were significantly associated with pain and opioid use using multiple logistic regression. CONCLUSIONS: Pharmacogenomic testing in this study was not predictive of pain and opioid use following TKA compared with psycho-social variables.

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement.

OBJECTIVES: Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA. MATERIALS AND METHODS: Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT). RESULTS: A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing. CONCLUSIONS: This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for Spinal Cord Stimulation Long-term Outcome Optimization and Salvage Therapy.

INTRODUCTION: The International Neuromodulation Society (INS) has recognized a need to establish best practices for optimizing implantable devices and salvage when ideal outcomes are not realized. This group has established the Neurostimulation Appropriateness Consensus Committee (NACC)® to offer guidance on matters needed for both our members and the broader community of those affected by neuromodulation devices. MATERIALS AND METHODS: The executive committee of the INS nominated faculty for this NACC® publication on the basis of expertise, publications, and career work on the issue. In addition, the faculty was chosen in consideration of diversity and inclusion of different career paths and demographic categories. Once chosen, the faculty was asked to grade current evidence and along with expert opinion create consensus recommendations to address the lapses in information on this topic. RESULTS: The NACC® group established informative and authoritative recommendations on the salvage and optimization of care for those with indwelling devices. The recommendations are based on evidence and expert opinion and will be expected to evolve as new data are generated for each topic. CONCLUSIONS: NACC® guidance should be considered for any patient with less-than-optimal outcomes with a stimulation device implanted for treating chronic pain. Consideration should be given to these consensus points to salvage a potentially failed device before explant.

An Anatomy-Informed, Novel Technique for S1 Dorsal Root Ganglion Stimulation Lead Placement.

OBJECTIVE: A heightened and organized understanding of sacral anatomy could potentially lead to a more effective and safe method of dorsal root ganglion stimulation (DRG-S) lead placement. The aim of this technical note is to describe a standardized access method for S1 DRG-S lead placement. DESIGN: Technical note. METHODS: The described approach utilizes alignment of the lumbosacral prominence and is measurement-based, allowing for standardized sacral access, even when visualization is suboptimal. The medial-to-lateral needle trajectory is designed to limit interaction with the sensitive neural structures and allows for a more parallel orientation of the lead to the DRG and nerve root. CONCLUSIONS: The described technique potentially improves the safety of S1 DRG-S lead placement. The parallel lead orientation to the DRG may also increase efficacy while lowering energy requirements.

A paramedian approach for dorsal root ganglion stimulation placement developed to limit lead migration and fracture.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S), has demonstrated superiority in the treatment of complex regional pain syndrome and causalgia. Lead migration and fracture impact DRG-S therapeutic stability. Lead anchoring reduces DRG-S lead migration without increasing lead fracture. Lead fracture may be related to lead entrapment in the superficial fascial plane. A novel medialized approach for lead placement and anchoring is presented to address these issues. METHODS: We suggest an alternative technique for implanting percutaneous DRG-S leads at the T10-L5 levels. RESULTS: A novel medialized ipsilateral technique for lead placement and anchoring for single, bilateral, and adjacent segment placement is presented. The Tuohy needle puncture site is medial to the pedicle and adjacent to the spinous process, two vertebral levels caudad to the target foramen. Trajectory is maintained in the sagittal plane, to access the caudad interlaminar space near the midline. This technique allows for ipsilateral or contralateral lead placement. After epidural access, the introducer sheath is rotated toward the targeted foramen and advanced. The guidewire followed by the lead is passed, and once lead position is confirmed, tension "S" loops are created, followed by anchoring to the deep fascia. CONCLUSION: We describe a new paramedian technique for DRG-S lead placement. We propose it will decrease DRG-S complication rates through anchoring to reduce migration and by avoiding the fascial planes thought to be responsible for fracture. Long-term outcomes applying our proposed techniques are required for determining the true impact, however, early anecdotal results suggest that these new techniques are favorable.

The impact of psychiatric comorbidities on patient-reported surgical outcomes in adults treated for the median arcuate ligament syndrome.

OBJECTIVE: Median arcuate ligament syndrome (MALS) is an often overlooked, surgically correctable condition that mimics functional chronic abdominal pain. Patient-reported surgical outcomes are unpredictable in MALS. The objective of this study was to define the psychiatric comorbidities in a cohort of adults undergoing surgery for MALS and to determine whether these comorbidities are predictive of patient-reported quality of life (QOL) outcomes. METHODS: A prospective observational trial was conducted between April 1, 2010, and December 31, 2015, at a single tertiary care hospital. Adults with a diagnosis of chronic abdominal pain in the setting of celiac artery compression were enrolled in a prospective Institutional Review Board-approved observational trial. Patients completed psychological assessments before surgery for MALS and at 6 months after surgery. The primary outcome was patient-reported health-related QOL (young adult version of the Pediatric Quality of Life Inventory). RESULTS: A total of 51 patients (80% female; n = 41) with a mean age of 30.5 (±12.4) years were enrolled. Surgery significantly improved celiac artery hemodynamics in the entire cohort (P < .0001) as well as overall QOL (67.8 ± 14.6 [before surgery] vs 80.3 ± 13.7 [after surgery]; P < .001). Psychiatric diagnoses were common in this cohort, with 14 of 51 (28%) patients meeting criteria for a psychiatric diagnosis. There were no differences in the number of patients with psychiatric diagnoses between presurgical and postsurgical evaluations (14 [28%] vs 13 [26%]; P = .8). Exploratory analyses suggest that having a psychiatric diagnosis at the presurgical evaluation may predict significantly lower postsurgical QOL (R2 = 0.009; P = .01). CONCLUSIONS: Surgery improves patient-reported QOL in adults treated for MALS. Psychiatric diagnoses are common in adults with MALS and predict worse patient-reported QOL outcomes.

Local anesthetic systemic toxicity.

Local anesthetic systemic toxicity (LAST) is a rare yet devastating complication from the administration of local anesthesia. The ability to recognize and treat LAST is critical for clinicians who administer these drugs. The authors reviewed the literature on the mechanism, treatment, and prevention of LAST, with the goal of proposing a practical method for its management.

Multiorganizational consensus to define guiding principles for perioperative pain management in patients with chronic pain, preoperative opioid tolerance, or substance use disorder.

Significant knowledge gaps exist in the perioperative pain management of patients with a history of chronic pain, substance use disorder, and/or opioid tolerance as highlighted in the US Health and Human Services Pain Management Best Practices Inter-Agency Task Force 2019 report. The report emphasized the challenges of caring for these populations and the need for multidisciplinary care and a comprehensive approach. Such care requires stakeholder alignment across multiple specialties and care settings. With the intention of codifying this alignment into a reliable and efficient processes, a consortium of 15 professional healthcare societies was convened in a year-long modified Delphi consensus process and summit. This process produced seven guiding principles for the perioperative care of patients with chronic pain, substance use disorder, and/or preoperative opioid tolerance. These principles provide a framework and direction for future improvement in the optimization and care of 'complex' patients as they undergo surgical procedures.

A multisociety organizational consensus process to define guiding principles for acute perioperative pain management.

The US Health and Human Services Pain Management Best Practices Inter-Agency Task Force initiated a public-private partnership which led to the publication of its report in 2019. The report emphasized the need for individualized, multimodal, and multidisciplinary approaches to pain management that decrease the over-reliance on opioids, increase access to care, and promote widespread education on pain and substance use disorders. The Task Force specifically called on specialty organizations to work together to develop evidence-based guidelines. In response to this report's recommendations, a consortium of 14 professional healthcare societies committed to a 2-year project to advance pain management for the surgical patient and improve opioid safety. The modified Delphi process included two rounds of electronic voting and culminated in a live virtual event in February 2021, during which seven common guiding principles were established for acute perioperative pain management. These principles should help to inform local action and future development of clinical practice recommendations.

Pharmacogenomic considerations for medications in the perioperative setting.

Several high-profile examples of adverse outcomes from medications used in the perioperative setting are well known (e.g., malignant hyperthermia, prolonged apnea, respiratory depression, inadequate analgesia), leading to an increased understanding of genetic susceptibilities underlying these risks. Pharmacogenomic information is increasingly being utilized in certain areas of medicine. Despite this, routine preoperative genetic screening to inform medication risk is not yet standard practice. In this review, we assess the current readiness of pharmacogenomic information for clinical consideration for several common perioperative medications, including description of key pharmacogenes, pharmacokinetic implications and potential clinical outcomes. The goal is to highlight medications for which emerging or considerable pharmacogenomic information exists and identify areas for future potential research.

Postoperative continuous adductor canal block for total knee arthroplasty improves pain and functional recovery: A randomized controlled clinical trial.

STUDY OBJECTIVE: Investigate the use of a postoperative continuous adductor canal block (cACB) after epidural analgesia to decreases opioid consumption and improve visual analog scale (VAS) scores compared to a sham catheter. DESIGN: Double-blinded randomized placebo-controlled trial. SETTING: Inpatient setting in tertiary care teaching hospital with outpatient follow-up. PATIENTS: One-hundred and sixty-five subjects (cACB n = 82 and sham catheter n = 83) with end-stage degenerative joint disease undergoing elective unilateral total knee arthroplasty. INTERVENTIONS: Patients were block randomized to receive a cACB or sham catheter. An epidural catheter was placed preoperatively and discontinued on postoperative day 1. Patients then received a cACB with bupivacaine or sham catheter which remained for the duration of the hospitalization. MEASUREMENTS: Primary outcome was total opioid consumption. Secondary outcomes included VAS scores, knee range of motion (ROM), ambulation distance, and WOMAC scores. MAIN RESULTS: Seventy patients completed the study (cACB n = 38 and sham catheter n = 32). Compared to sham catheter, in the first 20 h after placement of a cACB, patients used 22.5 mg less opioid (95% CI: -43.1 to -1.94 mg, P = 0.03). VAS score area under the curve decreased 7.8 mm (95% CI: -15.5 - -0.058 mm, P = 0.04) with a cACB. At 3-week follow-up, WOMAC scores were significantly improved with the cACB with a mean difference of 8.72 (95% CI: -17.3 to -0.11, P = 0.04). There were no statistically significant differences in secondary outcomes on postoperative day 2. Paired outcomes at 6 weeks compared to baseline ROM, showed significant improvement in knee ROM with a cACB (mean difference 11.77°, 95% CI: 3.1-20.5°, P = 0.01). CONCLUSION: A postoperative cACB after total knee arthroplasty significantly reduces total opioid consumption and pain scores compared to sham catheter. Ambulatory ability was not affected and patients recovered function earlier. ClinicalTrials.govNCT02121392.

Labor Epidural Intolerance Due to a Congenitally Narrowed Spinal Canal.

Reports exist of severe upper back pain of unknown etiology after administration of large volumes into the epidural space. We present a case of an otherwise healthy parturient who developed severe upper back and neck pain after receiving only a small volume of epidural medication. Magnetic resonance imaging revealed a congenitally narrowed spinal canal because of short pedicle syndrome. Epidural injectate occupies and compresses a percentage of the spinal canal and its neuronal contents. This may result in pain and epidural intolerance when continued injectate reaches a critical point, a threshold that is lower with shortened pedicles or congenital spinal stenosis. We believe a similar mechanism may explain the pain that patients sometimes experience after administration of large epidural volumes.

Acute pain management.

This article updates acute pain management in ambulatory surgery and proposes a practical three-step approach for reducing the impact and incidence of uncontrolled surgical pain. By identifying at-risk patients, implementing multimodal analgesia, and intervening promptly with rescue therapies, the anesthesiologist may improve outcomes, reduce cost, and optimize the patient's experience and quality of recovery.

Preparing for the physician payment sunshine act.

In March of 2010, President Barack Obama signed into law the Patient Protection and Affordable Care Act, ushering in an era of health care reform. Section 6002 of the bill, the Physician Payment Sunshine Act, requires manufacturers of drugs, devices, biological therapeutics, and medical supplies to disclose to the Centers for Medicare and Medicaid Services any payments or transfers of value to physicians. These reports are not meant to prohibit relationships between physicians and industry, but rather to generate a searchable public database illustrating the purpose of the payment, the entities involved, and the timing of each occurrence. Although the bill is meant to reveal physician-industry relationships, the question of how society at large and the medical field will interpret these data are unknown. The purpose of this article is to inform physicians of the components of the Physician Payment Sunshine Act. We discuss several resultant challenges and suggest a framework for preparing for transparency reporting and its potential effects.