Chronic Kidney Disease-Associated Pruritus and Quality of Life: Learning from Our Patients.

Chronic kidney disease-associated pruritus is itching directly related to kidney disease that cannot be explained by any other condition. Despite technological advances in the different aspects of dialysis sessions and the best treatment for chronic kidney disease patients, it is still a common problem in our patients. The many complex physiological mechanisms involved, the different hypotheses made over the years on the aetiology of the condition, and the great clinical variability may partially explain the limited knowledge about this problem and the difficulties in treating it. The presence of all these factors leads to the persistence of unpleasant symptoms, which must affect the disease burden and quality of life of kidney patients. Through the presentation of an illustrative clinical case, the aim of this review article is to highlight the need for adequate diagnosis and an improved approach to all aspects of chronic kidney disease-associated pruritus, in view of the heavy burden of the disease and the huge impact on the patient's quality of life.

Etiopathogenesis of chronic kidney disease-associated pruritus: putting the pieces of the puzzle together.

Defined as the unpleasant sensation that causes the desire to scratch, pruritus is the most common skin symptom associated with uremia and appears in almost half of patients with advanced chronic kidney disease (CKD). Beyond its direct impact on quality of life, CKD-associated pruritus (CKD-aP) is an independent predictor of mortality that also has a synergistic effect with other quality of life-related symptoms, such as insomnia, depression, and anxiety. Although different mechanisms have been proposed to explain the origin of Pa-ERC, its etiopathogenesis is still not fully understood. Since new therapeutic targets have been identified and several clinical trials have recently shown promising results, our current understanding of the interrelationships has expanded significantly and the pathophysiological mechanisms underlying CKD-aP are now considered to be multifactorial. The potential triggers of pruritus in patients with CKD are discussed in this review, including hypotheses about skin xerosis, accumulation of uremic toxins, dysregulation of the immune system and systemic inflammation, uremic neuropathy, and imbalances in the endogenous opioid system. Other non-uremic causes of pruritus are also discussed, with the aim of guiding the physicians to apply an adequate aetiopathogenic approach to CKD-aP in their day-to-day clinical practice.

Perception of Spanish nephrologists on an old unsolved problem: Pruritus associated with chronic kidney disease (CKD-aP).

INTRODUCTION: Pruritus associated with chronic kidney disease is defined as the sensation of itching, in people with chronic kidney disease, in a one area or all over the body that causes the need to scratch, after having ruled out other dermatological or systemic causes. It is an old and known problem whose prevalence has been able to decrease with the improvement of dialytic techniques but which still persists and is underdiagnosed. OBJECTIVES: The objective of this study was to analyse the current perception of nephrologists about this problem that influences the quality of life of people with chronic kidney disease through a survey. RESULTS: 135 nephrologists, most of them engaged in haemodialysis, participated. 86% considered that pruritus associated with chronic kidney disease is still a problem today that affects the quality of life. Most nephrologists believe that the main pathophysiological cause is uremic toxins (60%) and only 16% believe that it is due to the dysregulation of the opioid system/endorphins-dynorphins. Only 16% comment that the prevalence of pruritus in their centre is greater than 20%. 40% believe that the diagnosis is made because it is manifested by the patient and only 27% because it is asked by the doctor. Moreover, it is not usual to use scales to measure it or the codification in the medical records. The main treatment used is antihistamines (96%), followed by moisturizers/anaesthetics (93%) and modification of the dialysis regimen (70%). CONCLUSIONS: Pruritus associated with chronic kidney disease is still a current problem, it is underdiagnosed, not codified and with a lack of indicated, effective and safe treatments. Nephrologists do not know its real prevalence and the different pathophysiological mechanisms involved in its development. Many therapeutic options are used with very variable results, ignoring their efficacy and applicability at the present time. The new emerging kappa-opioid-receptor agonist agents offer us an opportunity to reevaluate this age-old problem and improve the quality of life for our patients with chronic kidney disease.

Etiopatogenia del prurito asociado a la enfermedad renal crónica: recomponiendo las piezas del puzle / Etiopathogenesis of chronic kidney disease-associated pruritus: Putting the pieces of the puzzle together

Definido como la sensación desagradable que provoca el deseo de rascarse, el prurito es el síntoma cutáneo más frecuente asociado a la uremia, pudiendo aparecer en casi la mitad de los pacientes con enfermedad renal crónica (ERC) avanzada. Más allá de su repercusión directa sobre la calidad de vida, el prurito asociado a la ERC (Pa-ERC) es un predictor independiente de mortalidad que además ejerce un efecto sinérgico con otros síntomas también relacionados con la calidad de vida, como la depresión y el insomnio. Aunque se han propuesto diferentes mecanismos para explicar su origen, la etiopatogenia del Pa-ERC sigue sin conocerse por completo. Dado que se han identificado nuevas dianas terapéuticas y recientemente varios ensayos clínicos han mostrado resultados prometedores, nuestra comprensión actual de las interrelaciones se ha ampliado significativamente, considerando multifactoriales los mecanismos fisiopatológicos subyacentes al Pa-ERC. En la presente revisión se discuten los potenciales factores desencadenantes de prurito en el paciente con ERC, incluyendo las hipótesis sobre la xerosis cutánea, el acúmulo de toxinas urémicas, la desregulación del sistema inmune y la inflamación sistémica, la neuropatía urémica y los desequilibrios en el sistema opioide endógeno, así como otras causas no urémicas de prurito, con el objetivo de orientar al clínico para realizar un adecuado abordaje etiopatogénico del Pa-ERC en su día a día. (AU)

Defined as the unpleasant sensation that causes the desire to scratch, pruritus is the most common skin symptom associated with uremia and appears in almost half of patients with advanced chronic kidney disease (CKD). Beyond its direct impact on quality of life, CKD-associated pruritus (CKD-aP) is an independent predictor of mortality that also has a synergistic effect with other quality of life-related symptoms, such as insomnia, depression, and anxiety. Although different mechanisms have been proposed to explain the origin of Pa-ERC, its etiopathogenesis is still not fully understood. Since new therapeutic targets have been identified and several clinical trials have recently shown promising results, our current understanding of the interrelationships has expanded significantly and the pathophysiological mechanisms underlying CKD-aP are now considered to be multifactorial. The potential triggers of pruritus in patients with CKD are discussed in this review, including hypotheses about skin xerosis, accumulation of uremic toxins, dysregulation of the immune system and systemic inflammation, uremic neuropathy, and imbalances in the endogenous opioid system. Other non-uremic causes of pruritus are also discussed, with the aim of guiding the physicians to apply an adequate etiopathogenic approach to CKD-aP in their day-to-day clinical practice. (AU)

Oral Anticoagulation in Patients with Chronic Kidney Disease and Non-Valvular Atrial Fibrillation: The FAERC Study.

Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and its presence is associated with a higher risk of stroke and mortality. MATERIAL AND METHODS: The FAERC study performed a retrospective multicentre analysis of historical cohorts in which data were collected from arrhythmia diagnosis onwards. RESULTS: We analysed a Spanish cohort of 4749 patients with CKD (mean eGFR 33.9 mL/min) followed up in the nephrology clinic, observing a 12.2% prevalence of non-valvular AF. In total, 98.6% of these patients were receiving anticoagulant treatment, mainly with coumarins (79.7%). Using direct-acting oral anticoagulants (DOACs) was associated with fewer cerebrovascular events than using acenocoumarol, but in contrast with other studies, we could not corroborate the association of risk of bleeding, coronary events, or death with a type of anticoagulant prescribed. CONCLUSIONS: Atrial fibrillation is highly prevalent in renal patients. Direct-acting anticoagulants seem to be associated with fewer ischemic-embolic complications, with no differences in bleeding, coronary events, or mortality rates.

Distinct Solute Removal Patterns by Similar Surface High-Flux Membranes in Haemodiafiltration: The Adsorption Point of View.

INTRODUCTION: Haemodialysis (HD) allow depuration of uraemic toxins by diffusion, convection, and adsorption. Online haemodiafiltration (HDF) treatments add high convection to enhance removal. There are no prior studies on the relationship between convection and adsorption in HD membranes. The possible benefits conferred by intrinsic adsorption on protein-bound uraemic toxins (PBUTs) removal are unknown. METHODS: Twenty-two patients underwent their second 3-days per week HD sessions with randomly selected haemodialysers (polysulfone, polymethylmethacrylate, cellulose triacetate, and polyamide copolymer) in high-flux HD and HDF. Blood samples were taken at the beginning and at the end of the treatment to assess the reduction ratio (RR) in a wide range of molecular weight uraemic toxins. A mid-range removal score (GRS) was also calculated. An elution protocol was implemented to quantify the amount of adsorbed mass (Mads) for each molecule in every dialyser. RESULTS: All synthetic membranes achieved higher RR for all toxins when used in HDF, specially the polysulfone haemodialyser, resulting in a GRS = 0.66 ± 0.06 (p < 0.001 vs. cellulose triacetate and polyamide membranes). Adsorption was slightly enhanced by convection for all membranes. The polymethylmethacrylate membrane showed expected substantial adsorption of ß2-microglobulin (MadsHDF = 3.5 ± 2.1 mg vs. MadsHD = 2.1 ± 0.9 mg, p = 0.511), whereas total protein adsorption was pronounced in the cellulose triacetate membrane (MadsHDF = 427.2 ± 207.9 mg vs. MadsHD = 274.7 ± 138.3 mg, p = 0.586) without enhanced PBUT removal. DISCUSSION/CONCLUSION: Convection improves removal and slightly increases adsorption. Adsorbed proteins do not lead to enhanced PBUTs depuration and limit membrane efficiency due to fouling. Selection of the correct membrane for convective therapies is mandatory to optimize removal efficiency.

Eficacia y seguridad de un programa de ejercicio físico intradiálisis / Impact and safety outcomes of an intradialytic physical exercise program

Introducción: Los pacientes en hemodiálisis (HD) suelen tener una condición física mermada y elevado sedentarismo. La consolidación de programas de ejercicio físico en las unidades de diálisis está limitada por barreras como la seguridad inherente a estos programas y la falta de recursos. Objetivos: Evaluar la eficacia y seguridad en la implantación de un programa de ejercicio físico intradiálisis (EFI) sobre la condición física de los pacientes con un equipo multidisciplinar (fisioterapeuta y auxiliares de enfermería). Material y métodos: Estudio cuasiexperimental pre-post unicéntrico prospectivo de 6 meses en 34 pacientes. Intervención con EFI combinado 2 días a la semana, evaluándose de forma basal y final la capacidad cardiorrespiratoria (6MWT), fuerza muscular (HG, dinamometría de cuádriceps y 10STS), la composición corporal (bioimpedanciometría) y la capacidad coordinativa (Timed Up and Go test). La seguridad se valoró registrando las incidencias relacionadas con el acceso vascular, la estabilidad hemodinámica y el perfil de rellenado vascular (RBV) durante las sesiones. También se registró la adherencia al programa así como parámetros analíticos habituales. Resultados: La adherencia al programa de EFI fue elevada (70,8%). Se constató una mejora significativa de 47m (p<0,001) en el 6MWT; un incremento medio de 1,6kg (p=0,007) en el HG para la fuerza de extremidades superiores y en las extremidades inferiores (10STS p=0,003; dinamometría p<0,05). Respecto a la seguridad, no se detectaron incidencias ni diferencias significativas en el RBV. Conclusiones: Un programa de EFI combinado favorece la mejora de la condición física de los pacientes en HD sin comprometer la seguridad del tratamiento. Es aconsejable un equipo multidisciplinar para implantar y dar continuidad eficazmente a un programa de EFI. (AU)

Introduction: Patients undergoing hemodialysis (HD) are characterized by a poor physical condition and a substantial sedentary profile. The implementation of physical exercise programs in the hemodialysis units is usually limited by the inherent safeness and the lack of appropriate resources. Objectives: We aimed to evaluate the impact and safety outcomes of the implementation of an intradialytic physical exercise program (IPE) by a multidisciplinary team (physiotherapist and nursing assistant) in the physical condition of the patients. Material and methods: This six months single-centre and experimental pre-post prospective study was carried out in 34 patients. A two day-week combined IPE intervention was implemented. The cardiopulmonary capacity (6MWT), muscular strength (HG, leg dynamometry and 10STS), body composition (bioimpedance) and coordination capacity (Timed Up and Go test) was assessed at the beginning and at the end of the study. Safety was evaluated by means of the number of issues regarding the vascular access, the hemodynamic stability as well as the vascular refilling profile (RBV) in each session. The adhesion to the program was also registered. Additionally, analytical parameters were recorded. Results: The adhesion to an IPE program was high (70.8%). A significant improvement of the cardiopulmonary capacity (6MWT average increase 47m; p<0.001), superior limbs (HG average increase of 1.6kg; p=0.007) as well as the lower extremities (10STS; p=0.003; dynamometry p<0.05). Regarding safeness, there were no incidences neither significant difference in the RBV. Conclusions: A combined IPE may contribute to the improvement of the physical condition of the patients as well as ensures a safe development of the HD treatment. We suggest a multidisciplinary team in order to efficiently establish an IPE program. (AU)

The Spanish Version of the Fear of Kidney Failure Questionnaire: Validity, Reliability, and Characterization of Living Donors With the Highest Fear of Kidney Failure.

BACKGROUND: Measures of fear of progression or recurrence of illnesses have been criticized for neglecting cross-cultural validity. Therefore, we assessed the psychometric properties of the Spanish version of the Fear of Kidney Failure Questionnaire (FKFQ), to determine whether postdonation fear of kidney failure (FKF) influenced the donors' psychosocial status, and define variables that characterized donors with high FKFQ scores. METHODS: We included 492 participants (211 donors) in a multicenter, 11-year, retrospective, cross-sectional study. Donors were classified with a Latent Class Analysis of the FKFQ-item scores and characterized with a multivariable logistic regression analysis. We calculated the risk ratio based on predicted marginal probabilities. RESULTS: The Spanish version of the FKFQ showed acceptable psychometric properties. FKF was uncommon among donors, but we detected a small subgroup (n = 21, 9.9%) with high FKF (mean FKFQ score = 14.5, 3.1 SD). Compared with other donors, these donors reported higher anxiety and depression (38% and 29% of potential anxiety and depressive disorders), worse quality of life, and less satisfaction with the donation. Donors with high FKFQ scores were characterized by higher neuroticism combined with postdonation physical symptoms that interfered with daily activities. CONCLUSIONS: The FKFQ was cross-culturally valid, and thus, it may be used to assess the FKF in Spanish-speaking donors. New interventions that promote positive affectivity and evidence-based treatments for worry could be adapted for treating FKF.