Pathways for Diagnosing and Treating CKD-Associated Pruritus: A Narrative Review.

Purpose of Review: Chronic kidney disease (CKD)-associated pruritus is a common, persistent, and distressing itch experienced by patients across the CKD spectrum. Although the disorder is associated with adverse outcomes and poor health-related quality of life, it remains underdiagnosed and undertreated. The purpose of this narrative review is to offer health care providers guidance on how to effectively identify, assess, and treat patients with CKD-associated pruritus, with the goal of reducing symptom burden and improving patient-important outcomes, such as quality of life (QoL). Sources of Information: A panel of nephrologists and researchers from across Canada and the United States was assembled to develop this narrative review based on the best available data, current treatment guidelines, and their clinical experiences. Methods: A panel of nephrologists who actively care for patients with pruritus receiving dialysis from across Canada was assembled. Two researchers from the United States were also included based on their expertise in the diagnosis and management of CKD-associated pruritus. Throughout Spring 2023, the panel met to discuss key topics in the identification, assessment, and management of CKD-associated pruritus. Panel members subsequently developed summaries of the pertinent information based on the best available data, current treatment guidelines, and added information on their own clinical experiences. In all cases, approval of the article was sought and achieved through discussion. Key Findings: This narrative review provides pragmatic guidance addressing: (1) methods for screening CKD-associated pruritus, (2) assessing severity, (3) management of CKD-associated pruritus, and (4) suggested areas for future research. The panel developed a 3-pillar framework for proactive assessment and severity scoring in CKD-aP: systematic screening for CKD-associated pruritus (pillar 1), assessment of pruritus intensity (pillar 2), and understanding the impact of CKD-associated pruritus on the patient's QoL (pillar 3). Management of CKD-associated pruritus can include ensuring optimization of dialysis adequacy, achieving mineral metabolism targets (ie, calcium, phosphate, and parathyroid hormone). However, treatment of CKD-associated pruritus usually requires additional interventions. Patients, regardless of CKD-associated pruritus severity, should be counseled on adequate skin hydration and other non-pharmacological strategies to reduce pruritus. Antihistamines should be avoided in favor of evidence-based treatments, such as difelikefalin and gabapentin. Limitations: A formal systematic review (SR) of the literature was not undertaken, although published SRs were reviewed. The possibility for bias based on the experts' own clinical experiences may have occurred. Key takeaways are based on the current available evidence, of which head-to-head clinical trials are lacking. Funding: This work was funded by an arm's length grant from Otsuka Canada Pharmaceutical Inc. (the importer and distributer of difelikefalin in Canada). LiV Medical Education Agency Inc. provided logistical and editorial support.

Motif de la revue: Le prurit associé à l'insuffisance rénale chronique (IRC) est une démangeaison cutanée fréquente, persistante et invalidante que les patients de tout le specter de l'IRC peuvent ressentir. Bien que le prurit soit associé à des effets indésirables et à une mauvaise qualité de vie liée à la santé, il demeure sous-diagnostiqué et sous-traité. L'objectif de cette revue narrative est d'offrir des conseils aux professionnels de la santé sur la façon d'identifier, d'évaluer et de traiter efficacement les patients atteints de prurit associé à l'IRC; ceci dans le but de réduire la charge des symptômes et d'améliorer les résultats importants pour les patients, notamment leur qualité de vie (QdV). Sources de l'information: Un comité de néphrologues et de chercheurs de partout au Canada et des États-Unis a été constitué pour élaborer la présente revue narrative à partir des meilleures données disponibles, des lignes directrices actuelles pour le traitement et de leurs expériences cliniques. Méthodologie: Un groupe de néphrologues canadiens qui s'occupent activement de patients dialysés souffrant de prurit a été constitué. Deux chercheurs des États-Unis ont été inclus au groupe en raison de leur expertise dans le diagnostic et la prise en charge du prurit associé à l'IRC. Le comité s'est réuni tout au long du printemps 2023 pour discuter de sujets clés en lien avec l'identification, l'évaluation et la prise en charge du prurit associé à l'IRC. Les membres du comité ont par la suite rédigé des résumés des informations pertinentes en se basant sur les meilleures données disponibles et les lignes directrices actuelles pour le traitement, auxquels ils ont ajouté des informations issues de leurs propres expériences cliniques. Dans tous les cas, l'approbation du manuscrit a été sollicitée et obtenue par discussion. Principaux résultats: Cette revue narrative offre des conseils pragmatiques sur les points suivants: (1) les méthodes de dépistage du prurit associé à l'IRC; (2) l'évaluation de sa gravité; (3) sa prise en charge; et (4) les domaines suggérés pour de futures recherches. Le comité a développé un cadre à trois piliers pour l'évaluation proactive du prurit associé à l'IRC et l'établissement d'un score de gravité: le dépistage systématique du prurit associé à l'IRC (pilier 1), l'évaluation de son intensité (pilier 2) et la compréhension de son impact sur la QdV du patient (pilier 3). La prise en charge du prurit associé à l'IRC peut inclure l'optimisation de l'adéquation de la dialyse et l'atteinte des cibles du métabolisme minéral (c.-à-d. calcium, phosphate et hormone parathyroïdienne). Cependant, son traitement nécessite habituellement des interventions supplémentaires. Les patients, quelle que soit la gravité du prurit associé à l'IRC, devraient être avisés d'hydrater adéquatement leur peau et informés des autres stratégies non pharmacologiques afin de réduire le prurit. On devrait éviter les antihistaminiques et les remplacer par des traitements fondés sur des données probantes comme la difélikéfaline et la gabapentine. Limites: Aucune revue systématique de la littérature n'a été formellement entreprise, bien que les revues systématiques publiées aient été examinées. La possibilité d'un biais fondé sur les expériences cliniques des experts est envisageable. Les principales conclusions de cette étude sont fondées sur les données probantes actuellement disponibles, pour lesquelles il n'existe pas d'essais cliniques comparatifs. Financement: Ces travaux ont été financés par une subvention indépendante d'Otsuka Canada Pharmaceutical Inc. (l'importateur et distributeur de la difélikéfaline au Canada). Un soutien logistique et éditorial a été fourni par liV Medical Education Agency Inc.

Creatinine index as a surrogate of lean body mass derived from urea Kt/V, pre-dialysis serum levels and anthropometric characteristics of haemodialysis patients.

BACKGROUND AND OBJECTIVES: Protein-energy wasting is common in long-term haemodialysis (HD) patients with chronic kidney disease and is associated with increased morbidity and mortality. The creatinine index (CI) is a simple and useful nutritional parameter reflecting the dietary skeletal muscle protein intake and skeletal muscle mass of the patient. Because of the complexity of creatinine kinetic modeling (CKM) to derive CI, we developed a more simplified formula to estimate CI in HD patients. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: A large database of 549 HD patients followed over more than 20 years including monthly CKM-derived CI values was used to develop a simple equation based on patient demographics, predialysis serum creatinine values and dialysis dose (spKt/V) using mixed regression models. RESULTS: The equation to estimate CI was developed based on age, gender, pre-dialysis serum creatinine concentrations and spKt/V urea. The equation-derived CI correlated strongly with the measured CI using CKM (correlation coefficient  = 0.79, p-value <0.001). The mean error of CI prediction using the equation was 13.47%. Preliminary examples of few typical HD patients have been used to illustrate the clinical relevance and potential usefulness of CI. CONCLUSIONS: The elementary equation used to derive CI using demographic parameters, pre-dialysis serum creatinine concentrations and dialysis dose is a simple and accurate surrogate measure for muscle mass estimation. However, the predictive value of the simplified CI assessment method on mortality deserves further evaluation in large cohorts of HD patients.

FGF-23 removal is improved by on-line high-efficiency hemodiafiltration compared to conventional high flux hemodialysis.

BACKGROUND: Reducing circulating levels of fibroblast growth factor-23 (FGF-23) in patients on renal replacement therapy (RRT) could appear as an appealing approach for cardiovascular events prevention. The purpose of our study was to compare the clearance of FGF-23 between high flux hemodialysis (HD) and on-line hemodiafiltration (OL-HDF) procedures. METHODS: Fifty-three patients were included in the HD group while 32 patients were included in the OL-HDF group. Serum pre- and post-dialysis FGF-23 levels were measured using a 2nd generation Human FGF-23 (C-Term) ELISA kit. RESULTS: Mean FGF-23 reduction rates were significantly higher in OL-HDF (55.7 ± 25.2%) versus HD (36.2 ± 28.6%) groups (P=.0001), as were calculated FGF-23 clearances (P=.015) and Kt/V-FGF-23 (P=.001). Overall, post-treatment FGF-23 levels were significantly lower than pre-treatment values in both groups (P<.01). CONCLUSIONS: OL-HDF achieves higher FGF-23 removal over high flux HD.

Online high-efficiency haemodiafiltration achieves higher serum free light chain removal than high-flux haemodialysis in multiple myeloma patients: preliminary quantitative study.

BACKGROUND: Fast reduction of serum free light chain (FLC) levels correlate with renal recovery in cast nephropathy. Because convection has the capacity to remove proteins of higher molecular weights, we hypothesized that haemodiafiltration (HDF) would be superior to haemodialysis (HD) for FLC clearance. METHODS: We retrospectively identified all renal replacement therapy (RRT) sessions performed in multiple myeloma patients with pre- and post-treatment FLC measurements during a 2-year period. Using kinetic modelling, we calculated reduction percentages corrected for net ultrafiltration, effective clearances, net mass removal and Kt/V for both kappa (κ) and lambda (λ) serum FLC. RESULTS: We analysed 27 (10 HD and 17 HDF) RRT sessions realized in a total of six subjects. HDF resulted in higher FLC removal rates when compared to HD. Moreover, high-efficiency (i.e. substitution volume > 15 L/session) HDF demonstrated median efficient FLC clearances roughly twice superior to high-flux HD for both κ (59.0 versus 33.8 mL/min, respectively; P < 0.01) and λ (40.5 versus 19.7 mL/min, respectively; P = 0.02) FLC. In post-dilution HDF treatments, corrected FLC reduction percentages positively correlated with substitution volumes. Total plasma proteins increased during RRT in the HDF group. CONCLUSIONS: This preliminary quantitative study demonstrates the superiority of high-efficiency HDF over high-flux HD for serum FLC removal in multiple myeloma patients on RRT. No negative impact on total plasma proteins was noted.