Opioids for chronic pain management in patients with dialysis-dependent kidney failure

The Gut Microbiome and Symptom Burden After Kidney Transplantation: An Overview and Research Opportunities

Many kidney transplant recipients continue to experience high symptom burden despite restoration of kidney function. High symptom burden is a significant driver of quality of life. In the post-transplant setting, high symptom burden has been linked to negative outcomes including medication non-adherence, allograft rejection, graft loss, and even mortality. Symbiotic bacteria (microbiota) in the human gastrointestinal tract critically interact with the immune, endocrine, and neurological systems to maintain homeostasis of the host. The gut microbiome has been proposed as an underlying mechanism mediating symptoms in several chronic medical conditions including irritable bowel syndrome, chronic fatigue syndrome, fibromyalgia, and psychoneurological disorders via the gut-brain-microbiota axis, a bidirectional signaling pathway between the enteric and central nervous system. Post-transplant exposure to antibiotics, antivirals, and immunosuppressant medications results in significant alterations in gut microbiota community composition and function, which in turn alter these commensal microorganisms' protective effects. This overview will discuss the current state of the science on the effects of the gut microbiome on symptom burden in kidney transplantation and future directions to guide this field of study.

Calciphylaxis and Intractable Pain in a Veteran with Psychological Trauma History

Guidelines are lacking for patients with calciphylaxis on renal replacement therapy, often leading to difficulty optimally treating these patients. A 60-year-old male veteran receiving hemodialysis presented with calciphylaxis of the left lower extremity and intractable pain. His condition was complicated by chronic back pain, long-term opioid therapy, and psychological trauma history. He was ultimately transferred to a calciphylaxis treatment center but was unable to tolerate further treatments due to sepsis and hemodynamic instability. He was transitioned to comfort measures and died in the hospital. Addressing complicated pain physiologies and complex trauma is challenging even in well-resourced tertiary medical centers. Despite the availability of calciphylaxis therapies and trauma-informed care, there remains a high rate of suffering and mortality in this patient population. There is much work to be done in this cohort, particularly when considering the implications of past traumatic experiences on health care engagement and pain management.

Construction of injectable micron-sized polymorphic vesicles for prolonged local anesthesia with weekly sustained release of ropivacaine

Currently, to overcome the short half-life of the local anesthetic ropivacaine, drug delivery systems such as nanoparticles and liposomes have been used to prolong the analgesic effect, but they are prone to abrupt release from the site of administration or have poor slow-release effects, which increases the risk of cardiotoxicity. In this study, injectable lipid suspensions based on ropivacaine-docusate sodium hydrophobic ion pairing (HIP) were designed to significantly prolong the duration of analgesia. The resulting ion-paired lipid suspension (HIP/LIPO) had a micrometer scale and a high zeta potential, which facilitates stable in situ retention. The strong interaction between docusate sodium and ropivacaine was verified using thermal and spectroscopic analyses, and the formation of micron-sized polymorphic vesicles was attributed to the mutual stabilizing interactions between ropivacaine-docusate sodium HIP, docusate sodium and lecithin. The HIP/LIPO delivery system could maintain drug release for more than 5 days in vitro and achieve high analgesic efficacy for more than 10 days in vivo, reducing the side effects associated with high drug doses. The stable HIP/LIPO delivery system is a promising strategy that offers a clinically beneficial alternative for postoperative pain management and other diseases.

The impact of Yoga on patients with knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The objective of this review is to conduct a comprehensive and systematic assessment of the efficacy of Yoga as an intervention for knee osteoarthritis (KOA).

METHODS

We searched PubMed, Cochrane Library, Embase, Web of Science, and PEDro as of January 3, 2024. Retrieved a total of 200 articles. Standardised mean differences (SMDs) and 95% confidence intervals (CI) were calculated.

RESULTS

The study included a total of 8 trials and involved 756 KOA patients. The results indicated that compared to the control group, Yoga exercise showed significant improvements in alleviating pain (SMD = -0.92; 95% CI = -1.64 ~ - 0.20; P = 0.01, I2 = 94%), stiffness (SMD = -0.51; 95% CI = -0.91 ~ -0.12; P = 0.01; I2 = 66%) and physical function (SMD = -0.53; 95% CI = -0.89 ~ -0.17; P = 0.004; I2 = 59%) among KOA patients. However, there was no significant improvement observed in terms of activities of activity of daily living (ADL) (SMD = 1.03; 95% CI = -0.01 ~ 2.07; P = 0.05; I2 = 84%), and quality of life (QOL) (SMD = 0.21; 95% CI = -0.33 ~ 0.74; P = 0.44; I2 = 83%) with the practice of Yoga.

CONCLUSIONS

In general, Yoga has been found to be effective in reducing pain and stiffness in KOA patients, it can also improve the physical function of patients. However, there is limited evidence to suggest significant improvements in terms of ADL and QOL.

Development and Validation of a Treatment Algorithm for Osteoarthritis Pain Management in Patients With End-Stage Kidney Disease Undergoing Hemodialysis

Background

Although osteoarthritis is common in the hemodialysis population and leads to poor health outcomes, pain management is challenged by the absence of clinical guidance. A treatment algorithm was developed and validated to aid hemodialysis clinicians in managing osteoarthritis pain.

Objective

The objective was to develop and validate a treatment algorithm for managing osteoarthritis pain in patients undergoing hemodialysis.

Design

A validation study was conducted based on Lynn's method for content validation.

Setting

To develop and validate a treatment algorithm, interviews were conducted virtually by the primary researcher with clinicians from various institutions across the Greater Toronto and Hamilton Area in Ontario.

Patients

The treatment algorithm was developed and validated for the management of osteoarthritis pain in patients on hemodialysis. Patients were not involved in the development or validation of the tool.

Measurements

The algorithm was measured for content and face validity. Content validity was measured by calculating the content validity index of each component (I-CVI) of the algorithm and the overall scale validity index (S-CVI). Face validity was assessed by calculating the percentage of positive responses to the face validity statements.

Methods

A draft algorithm was developed based on literature searches and expert opinion and validated by interviewing nephrology and pain management clinicians. Through consecutive rounds of 1:1 interviews, content and face validity were assessed by asking participants to rate the relevance of each component of the algorithm and indicate their level of agreeability with a series of statements. Following each round, the I-CVI of the algorithm as well as the S-CVI was calculated and the percentage of positive responses to the statements was determined. The research team revised the algorithm in response to the findings. The final algorithm provides a stepwise approach to the non-pharmacologic and pharmacologic management of pain, including topical, oral, and opioid use.

Results

A total of 18 clinicians from 7 institutions across the Greater Toronto and Hamilton Area were interviewed (10 pharmacists, 5 nurse practitioners, and 3 physicians). The average S-CVI of the algorithm across all 3 rounds was 0.93. At least 78% of participants provided positive responses to the face validity statements.

Limitations

An algorithm was developed based on input from clinicians working in the province of Ontario, limiting the generalizability of the algorithm across provinces. In addition, the algorithm did not include the perspectives of primary care providers or patients/caregivers.

Conclusions

An algorithm for the management of osteoarthritis pain in the hemodialysis population was developed and validated through expert review to standardize practices and encourage clinicians to use evidence-based treatments and address the psychosocial symptoms of pain. As the algorithm possesses a high degree of content and face validity, it may improve osteoarthritis pain management among patients undergoing hemodialysis. Future research will assess the implementation of the algorithm across hemodialysis settings.

Problems with opioids - beyond misuse

The U.S. is grappling with an opioid epidemic, with millions of adults on long-term opioid therapy (LTOT). Although patients often report pain relief and improved daily function with opioids, research shows no significant differences in short-term outcomes between opioid and non-opioid users, as well as no long-term opioid benefits. This scoping review aims to identify lesser-known side effects of long-term opioid use and increase awareness of them, allowing healthcare providers and patients to better assess the risks and benefits of opioid use. Our data search from PubMed and Google Scholar used keywords related to opioids, chronic pain, hypogonadism, endocrinopathies, cancer progression, cardiovascular events, renovascular events, sleep disturbances, mood disorders and others, narrowing down to English-language full articles published from January 2018 to April 2023. This review emphasizes the probable serious adverse consequences of long-term opioid use on various body systems in patients with chronic pain. Given the lack of long-term benefits and significant adverse effects, our review underscores the critical need for healthcare providers to include these risks in discussions with patients when considering the long-term use of opioid therapy.

Evaluating the association between opium abuse, blood lead levels, and the complexity of coronary artery disease

Opium abuse and exposure to heavy metals elevate the risk of coronary artery disease (CAD). Therefore, we aimed to determine the association between opium abuse and blood lead levels (BLLs) and the CAD complexity. We evaluated patients with acute coronary symptoms who underwent coronary angiography, and those with >50% stenosis in at least one of the coronary arteries were included. Furthermore, Synergy between PCI with Taxus and Cardiac Surgery I (SYNTAX I) score and BLLs were measured. Based on the opium abuse, 95 patients were subdivided into opium (45) and control (50) groups. Differences in demographics and CAD risk factors were insignificant between the two groups. The median BLLs were remarkably higher in the opium group than in controls (36 (35.7) and 20.5 μg/dL (11.45), respectively, p = 0.003). We also revealed no significant differences in SYNTAX score between the two groups (15.0 (9.0) and 17.5 (14.0), respectively, p = 0.28). Additionally, we found no significant correlation between BLLs and the SYNTAX scores (p = 0.277 and r = -0.113). Opium abuse was associated with high BLLs. Neither opium abuse nor high BLLs were correlated with the complexity of CAD. Further studies are warranted to establish better the relationship between opium abuse, BLLs, and CAD.

Emodin inhibits HDAC6 mediated NLRP3 signaling and relieves chronic inflammatory pain in mice

Chronic pain reduces the quality of life and ability to function of individuals suffering from it, making it a common public health problem. Neuroinflammation which is mediated by the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation in the spinal cord participates and modulates chronic pain. A chronic inflammatory pain mouse model was created in the current study by intraplantar injection of complete Freund's adjuvant (CFA) into C57BL/6J left foot of mice. Following CFA injection, the mice had enhanced pain sensitivities, decreased motor function, increased spinal inflammation and activated spinal astrocytes. Emodin (10 mg/kg) was administered intraperitoneally into the mice for 3 days. As a result, there were fewer spontaneous flinches, higher mechanical threshold values and greater latency to fall. Additionally, in the spinal cord, emodin administration reduced leukocyte infiltration level, downregulated protein level of IL-1β, lowered histone deacetylase (HDAC)6 and NLRP3 inflammasome activity and suppressed astrocytic activation. Emodin also binds to HDAC6 via four electrovalent bonds. In summary, emodin treatment blocked the HDAC6/NLRP3 inflammasome signaling, suppresses spinal inflammation and alleviates chronic inflammatory pain.

The design and baseline characteristics for the HOPE Consortium Trial to reduce pain and opioid use in hemodialysis

The HOPE Consortium Trial to Reduce Pain and Opioid Use in Hemodialysis (HOPE Trial) is a multicenter randomized trial addressing chronic pain among patients receiving maintenance hemodialysis for end-stage kidney disease. The trial uses a sequential, multiple assignment design with a randomized component for all participants (Phase 1) and a non-randomized component for a subset of participants (Phase 2). During Phase 1, participants are randomized to Pain Coping Skills Training (PCST), an intervention designed to increase self-efficacy for managing pain, or Usual Care. PCST consists of weekly, live, coach-led cognitive behavioral therapy sessions delivered by video- or tele-conferencing for 12 weeks followed by daily interactive voice response sessions delivered by telephone for an additional 12 weeks. At 24 weeks (Phase 2), participants in both the PCST and Usual Care groups taking prescription opioid medications at an average dose of ≥20 morphine milligram equivalents per day are offered buprenorphine, a partial opioid agonist with a more favorable safety profile than full-agonist opioids. All participants are followed for 36 weeks. The primary outcome is pain interference ascertained, for the primary analysis, at 12 weeks. Secondary outcomes include additional patient-reported measures and clinical outcomes including falls, hospitalizations, and death. Exploratory outcomes include acceptability, tolerability, and efficacy of buprenorphine. The enrollment target of 640 participants was met 27 months after trial initiation. The findings of the trial will inform the management of chronic pain, a common and challenging issue for patients treated with maintenance hemodialysis. NCT04571619.

Opioids and the Kidney: A Compendium

Opioids are a class of medications used in pain management. Unfortunately, long-term use, overprescription, and illicit opioid use have led to one of the greatest threats to mankind: the opioid crisis. Accompanying the classical analgesic properties of opioids, opioids produce a myriad of effects including euphoria, immunosuppression, respiratory depression, and organ damage. It is essential to ascertain the physiological role of the opioid/opioid receptor axis to gain an in-depth understanding of the effects of opioid use. This knowledge will aid in the development of novel therapeutic interventions to combat the increasing mortality rate because of opioid misuse. This review describes the current knowledge of opioids, including the opioid epidemic and opioid/opioid receptor physiology. Furthermore, this review intricately relates opioid use to kidney damage, navigates kidney structure and physiology, and proposes potential ways to prevent opioid-induced kidney damage.

Should Buprenorphine Be Considered a First-Line Opioid for the Treatment of Moderate to Severe Cancer Pain?

Cancer pain remains a significant problem worldwide, affecting more than half of patients receiving anti-cancer treatment and most patients with advanced disease. Opioids remain the cornerstone of therapy, and morphine, given its availability, multiple formulations, price, and evidence base, is typically considered the first-line treatment for moderate to severe cancer pain. Buprenorphine has emerged in recent decades as an alternative opioid for treating chronic pain and substance use disorder (SUD). However, it remains controversial whether buprenorphine should be considered a first-line opioid for moderate to severe cancer pain. In this "Controversies in Palliative Care" article, three expert clinicians independently answer this question. Specifically, each group provides a synopsis of the key studies that inform their thought process, share practical advice on their clinical approach, and highlight the opportunities for future research. All three groups agree that there is a place for the use of buprenorphine as a first-line opioid in cancer pain. Specifically, they mention populations of elderly patients, patients with renal failure, and those with (SUD). They also underscore many unique and favorable characteristics of buprenorphine, such as the low risk for respiratory depression, lack of adverse effects on testosterone levels in men, no risk of serotonin syndrome when combined with antidepressants, and ease of use given its transdermal, transmucosal, and sublingual formulations. However, further studies are needed to guide the use of buprenorphine for cancer pain-primarily randomized clinical trials (RCTs) comparing buprenorphine with other opioids in various pain syndromes.

The Endogenous Opioid Met-Enkephalin Modulates Thalamo-Cortical Excitation Inhibition Balance in a Medial Thalamus-Anterior Cingulate Cortex Circuit

Activation of opioid receptors in the anterior cingulate cortex (ACC) mediates aspects of analgesia induced by both exogenous and endogenous opioids. We have previously shown that opioid signaling disrupts both afferent excitatory and indirect inhibitory synaptic transmission from the medial thalamus (MThal) to the ACC, but the effects of endogenous opioids within this circuit remain poorly understood. The goal of the current study was to understand how the endogenous opioid, [Met]5-enkephalin (ME), modulates thalamic-driven excitatory and inhibitory synaptic transmission onto layer V pyramidal neurons in the ACC. We used pharmacology, brain slice electrophysiology and optogenetic stimulation to study opioid-mediated modulation of optically evoked glutamatergic and GABAergic transmission. The results revealed that ME inhibited both AMPA-mediated excitatory and GABA-mediated inhibitory synaptic transmission in the ACC. However, inhibitory transmission was more potently inhibited than excitatory transmission by ME. This preferential reduction in GABAA-mediated synaptic transmission was primarily due to the activation of delta opioid receptors by ME and resulted in a net disinhibition of MThal-ACC excitatory pathway. These results suggest that moderate concentrations of ME can lead to net excitation of ACC circuitry and that analgesia may be associated with disinhibition rather than inhibition of ACC subcircuits.

Sickness Symptoms in Kidney Transplant Recipients: A Scoping Review

Sickness symptoms (depressive symptoms, anxiety, and fatigue) are common among people with chronic illness, often presenting as a symptom cluster. Sickness symptoms persist in many patients with chronic kidney disease, even after kidney transplantation (KT); however, little is known about sickness symptom-induced burden in KT recipients. This scoping review synthesizes available evidence for sickness symptoms in KT recipients, including findings on symptom prevalence, predictors, outcomes, interrelationships, and clustering. Among 38 reviewed studies, none identified sickness symptoms as a cluster, but we observed interrelationships among the symptoms examined. Fatigue was the most prevalent sickness symptom, followed by anxiety and depressive symptoms. Predictors of these symptoms included demographic, clinical, and psychosocial factors, and health-related quality of life was the most researched outcome. Future research should use common data elements to phenotype sickness symptoms, include biological markers, and employ sophisticated statistical methods to identify potential clustering of sickness symptoms in KT recipients.

Mechanism of opioid addiction and its intervention therapy: Focusing on the reward circuitry and mu-opioid receptor

Opioid abuse and addiction have become a global pandemic, posing tremendous health and social burdens. The rewarding effects and the occurrence of withdrawal symptoms are the two mainstays of opioid addiction. Mu-opioid receptors (MORs), a member of opioid receptors, play important roles in opioid addiction, mediating both the rewarding effects of opioids and opioid withdrawal syndrome (OWS). The underlying mechanism of MOR-mediated opioid rewarding effects and withdrawal syndrome is of vital importance to understand the nature of opioid addiction and also provides theoretical basis for targeting MORs to treat drug addiction. In this review, we first briefly introduce the basic concepts of MORs, including their structure, distribution in the nervous system, endogenous ligands, and functional characteristics. We focused on the brain circuitry and molecular mechanism of MORs-mediated opioid reward and withdrawal. The neuroanatomical and functional elements of the neural circuitry of the reward system underlying opioid addiction were thoroughly discussed, and the roles of MOR within the reward circuitry were also elaborated. Furthermore, we interrogated the roles of MORs in OWS, along with the structural basis and molecular adaptions of MORs-mediated withdrawal syndrome. Finally, current treatment strategies for opioid addiction targeting MORs were also presented.

Epidemiology of haemodialysis outcomes

Haemodialysis (HD) is the commonest form of kidney replacement therapy in the world, accounting for approximately 69% of all kidney replacement therapy and 89% of all dialysis. Over the last six decades since the inception of HD, dialysis technology and patient access to the therapy have advanced considerably, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes vary widely across the world and, overall, the rates of impaired quality of life, morbidity and mortality are high. Cardiovascular disease affects more than two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality. In addition, patients on HD have high symptom loads and are often under considerable financial strain. Despite the many advances in HD technology and delivery systems that have been achieved since the treatment was first developed, poor outcomes among patients receiving HD remain a major public health concern. Understanding the epidemiology of HD outcomes, why they might vary across different populations and how they might be improved is therefore crucial, although this goal is hampered by the considerable heterogeneity in the monitoring and reporting of these outcomes across settings.

This Review examines the epidemiology of haemodialysis outcomes — clinical, patient-reported and surrogate outcomes — across world regions and populations, including vulnerable individuals. The authors also discuss the current status of monitoring and reporting of haemodialysis outcomes and potential strategies for improvement.

Nearly 4 million people in the world are living on kidney replacement therapy (KRT), and haemodialysis (HD) remains the commonest form of KRT, accounting for approximately 69% of all KRT and 89% of all dialysis.

Dialysis technology and patient access to KRT have advanced substantially since the 1960s, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes continue to vary widely across countries, particularly among disadvantaged populations (including Indigenous peoples, women and people at the extremes of age).

Cardiovascular disease affects over two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality; mortality among patients on HD is significantly higher than that of their counterparts in the general population, and treated kidney failure has a higher mortality than many types of cancer. Patients on HD also experience high burdens of symptoms, poor quality of life and financial difficulties.

Careful monitoring of the outcomes of patients on HD is essential to develop effective strategies for risk reduction. Outcome measures are highly variable across regions, countries, centres and segments of the population. Establishing kidney registries that collect a variety of clinical and patient-reported outcomes using harmonized definitions is therefore crucial.

Evaluation of HD outcomes should include the impact on family and friends, and personal finances, and should examine inequities in disadvantaged populations, who comprise a large proportion of the HD population.