Changes in serum sodium concentration during hemodialysis is a predictor of mortality and cardio-cerebrovascular event

BACKGROUND

Previous study consistently showed that lower serum sodium (SNa) was associated with a greater risk of mortality in hemodialysis (HD) patients. However, few studies have focused on the change in SNa (ΔSNa = post-HD SNa - pre-HD SNa) during an HD session.

METHODS

In a retrospective cohort of maintenance HD adults, all-cause mortality and cardio-cerebrovascular event (CCVE) were followed up for a medium of 82 months. Baseline pre-HD SNa and ΔSNa were collected; time-averaged pre-HD SNa and ΔSNa were computed as the mean values within 1-year, 2-year and 3-year intervals after enrollment. Cox proportional hazards models were used to evaluate the relationships of pre-HD and ΔSNa with outcomes.

RESULTS

Time-averaged pre-HD SNa were associated with all-cause mortality (2-year pre-HD SNa: HR [95% CI] 0.86 [0.74-0.99], p = 0.042) and CCVE (3-year pre-HD SNa: HR [95% CI] 0.83 [0.72-0.96], p = 0.012) with full adjustment. Time-averaged ΔSNa also demonstrated an association with all-cause mortality (3-year ΔSNa: HR [95% CI] 1.26 [1.03-1.55], p = 0.026) as well as with CCVE (3-year ΔSNa: HR [95% CI] 1.51 [1.21-1.88], p = <0.001) when fully adjusted. Baseline pre-HD SNa and ΔSNa didn't exhibit association with both outcomes.

CONCLUSIONS

Lower time-averaged pre-HD SNa and higher time-averaged ΔSNa were associated with a greater risk of all-cause mortality and CCVE in HD patients.

High volume online hemodiafiltration: a global perspective and the Brazilian experience

Online hemodiafiltration (HDF) is a rapidly growing dialysis modality worldwide. In Brazil, the number of patients with private health insurance undergoing HDF has exceeded the number of patients on peritoneal dialysis. The achievement of a high convection volume was associated with better clinical imprand patient - reported outcomes confirming the benefits of HDF. The HDFit trial provided relevant practical information on the implementation of online HDF in dialysis centers in Brazil. This article aims to disseminate technical information to improve the quality and safety of this new dialysis modality.

Brazilian Dialysis Survey 2022

INTRODUCTION

The Brazilian Dialysis Survey (BDS) is an annual national survey about patients on chronic dialysis that contributes to health policies.

OBJECTIVE

To report the 2022 epidemiological data from the BDS of the Brazilian Society of Nephrology (BSN).

METHODS

A survey was carried out in Brazilian chronic dialysis centers using an online questionnaire that included clinical and epidemiological aspects of patients on chronic dialysis, dialysis therapy data, and dialysis center characteristics.

RESULTS

Overall, 28% (n = 243) of the centers answered the questionnaire. In July 2022, the estimated total number of patients on dialysis was 153,831. The estimated prevalence and incidence rates of patients per million population (pmp) were 758 and 214, respectively. Of the prevalent patients, 95.3% were on hemodialysis (HD, 4.6% of these on hemodiafiltration) and 4.7% on peritoneal dialysis (PD). Only 1.3% of patients were not vaccinated against COVID-19. The prevalence of anemia (Hb < 10g/dL) was 27% and hyperphosphatemia (P > 5.5mg/dL) reached 30%. The estimated overall crude annual mortality rate was 17.1%.

CONCLUSIONS

The absolute number and prevalence rate of patients on chronic dialysis continue to increase. A growing number of patients were receiving hemodiafiltration. The mortality rate decreased, probably due to the end of COVID-19 pandemic. The conclusions were drawn in the context of relatively low voluntary participation, which imposed methodological limitations on our estimates.

Impact of Albumin Leakage on the Mortality of Patients Receiving Hemodialysis or Online Hemodiafiltration

Background: Online hemodiafiltration (OHDF) has a lower mortality rate than hemodialysis (HD). We aimed to investigate the impact of the albumin leakage on the mortality of patients receiving HD or OHDF. Methods: In this single-center study, consecutive patients receiving renal replacement therapy between January and April 2018 were retrospectively registered. Using (1:1) propensity score matching, 3-year all-cause mortality was compared between patients receiving HD and OHDF, and the impact of albumin leakage on the mortality rate in both groups was investigated. Results: Of the 460 patients, 137 patients receiving HD were matched with an equal number of patients receiving OHDF. OHDF was associated with higher albumin leakage (p < 0.001) and a lower mortality than HD (log-rank test, p < 0.001). Albumin leakage was associated with mortality in patients receiving HD (per 1 g increase, hazard ratio (HR): 0.495, 95% confidence interval (CI): 0.275-0.888) and patients receiving OHDF (per 1 g increase, HR: 0.734, 95% CI: 0.588-0.915). Patients receiving HD, with the highest albumin leakage tertile (>3 g), had a similar mortality rate to patients receiving OHDF, with similar albumin leakage. Conclusions: The negative relationship between albumin leakage and mortality suggests the benefit of removing middle- to -large-molecular-weight substances to improve survival.

Fatalistic and Optimistic Coping Strategies Predict Depression in Arab Muslim Patients With End-Stage Renal Disease

BACKGROUND

Depression is one of the common psychological problems in patients on hemodialysis. We aimed to identify the predictors associated with depressive symptoms among patients on hemodialysis from a population under-represented in research and minoritized in countries like the United States.

METHODS

This cross-sectional study used a convenience sample of patients in Oman. Data were analyzed using linear multiple regression.

RESULTS

A total of 157 patients on hemodialysis participated in the study, with 40.5% reporting different levels of depressive symptoms. Higher stress levels (β = .643; p < .01) and higher perceived effectiveness of the fatalistic coping style (β = .144; p < .05) were significant predictors of depressive symptoms. Patients with a higher optimistic coping style (β = -.182; p < .01) had lower levels of depressive symptoms.

CONCLUSION

Arab Muslim hemodialysis patients have significant levels of depressive symptoms. Identifying predictors of depressive symptoms may help identify those at risk and provide culturally appropriate interventions.

ABCs of hemodiafiltration prescription: The Pisa style

In end-stage kidney disease patients, hemodiafiltration, a mixed diffusive-convective technique, has shown beneficial effects in terms of improvement of anemia, inflammation, mineral bone disorders, malnutrition and cardiovascular stability. Greater convective volume exchange was also associated with improved overall and cardiovascular survival. However, absolute target threshold volume would be difficult to define and achieve in daily clinical practice, mainly because of differences in patient size. Convective volumes standardized for body surface area would appear to be the simplest approach in clinical practice. Several factors can affect achievement of optimal convective volume, with vascular access being the main limiting factor. Based on our own clinical experience, hemodiafiltration is a more effective and preferable dialysis technique but only when a target convective volume greater than 20 L can be achieved. Conversely, standard high flux hemodialysis or expanded hemodialysis may be helpful and valuable alternative dialysis techniques.

Middle Molecular Uremic Toxin and Blood Purification Therapy

The purpose of blood purification therapy is to remove uremic toxins, and middle molecules (MMs) are a specific target. An MM is defined as a solute that passes through the glomerulus with a molecular weight in the range of 0.5-58 kDa, and new classifications of "small-middle 0.5-15 kDa," "medium-middle 15-25 kDa," and "large-middle 25-58 kDa" were proposed. In Japan, the removal of α1-microglobulin (αMG) in the large-middle range has been the focus, but a new theory of removal has been developed, emphasizing the antioxidant effect of αMG as a physiological function. Clinical proof of this mechanism will lead to further development of blood purification therapies.

Effects of nutritional supplementation stabilizing muscle mass loss in older patients on hemodiafiltration

BACKGROUND & AIMS

Malnutrition is common in older individuals with end-stage renal disease on maintenance dialysis. Whether nutritional supplementation may improve skeletal muscle mass (SMM) and survival rate in this population is uncertain. We aimed to analyze the effect of a year of nutritional supplementation on muscle mass and survival rate in older patients on hemodiafiltration.

METHODS

In this observational study, older patients (≥65 years old) on maintenance hemodiafiltration were selected to receive nutritional counselling + nutritional supplementation (N = 85, Supp+) or nutritional counselling alone (N = 47, Supp-) and followed for 1 year. The outcomes were a change in SMM and sarcopenia diagnosis. The secondary outcome was 1-year mortality rate. Nutritional parameters included calf circumference, body mass index, anthropometric measurements, subjective global assessment, and handgrip strength (HGS). Data were evaluated using GLM for repeated measures with adjustment for covariates (age and diabetes).

RESULTS

Malnutrition was found in 50.8% of patients. At baseline, patients from the Supp+ group were older and had worse nutritional parameters including hand grip strength, calf circumference, anthropometric findings and sarcopenia (all p values < 0.05). During the follow-up, there was no significant change in sarcopenia (from 50.8% to 58.3%, p = 0.108), and there was a more pronounced decrease in the SMM index in the Supp-group (p = 0.049), with a significant intervention interaction (p = 0.030). Twenty deaths occurred, 7 (35%) in the Supp- and 13 (65%) in the Supp+ group (p = 0.540). SMM index (relative risk 0.90, p = 0.030) and age (relative risk 1.07, p = 0.046) were independently associated with higher mortality rates.

CONCLUSION

Nutritional supplementation in older and malnourished individuals undergoing hemodiafiltration mitigates the loss of the SMM index and benefits survival rate.

Long-term peridialytic blood pressure changes are related to mortality

BACKGROUND

In chronic haemodialysis (HD) patients, the relationship between long-term peridialytic blood pressure (BP) changes and mortality has not been investigated.

METHODS

To evaluate whether long-term changes in peridialytic BP are related to mortality and whether treatment with HD or haemodiafiltration (HDF) differs in this respect, the combined individual participant data of three randomized controlled trials comparing HD with HDF were used. Time-varying Cox regression and joint models were applied.

RESULTS

During a median follow-up of 2.94 years, 609 of 2011 patients died. As for pre-dialytic systolic BP (pre-SBP), a severe decline (≥21 mmHg) in the preceding 6 months was independently related to increased mortality [hazard ratio (HR) 1.61, P = .01] when compared with a moderate increase. Likewise, a severe decline in post-dialytic diastolic BP (DBP) was associated with increased mortality (adjusted HR 1.96, P < .0005). In contrast, joint models showed that every 5-mmHg increase in pre-SBP and post-DBP during total follow-up was related to reduced mortality (adjusted HR 0.97, P = .01 and 0.94, P = .03, respectively). No interaction was observed between BP changes and treatment modality.

CONCLUSION

Severe declines in pre-SBP and post-DBP in the preceding 6 months were independently related to mortality. Therefore peridialytic BP values should be interpreted in the context of their changes and not solely as an absolute value.

Unveiling the Clinical Benefits of High-Volume Hemodiafiltration: Optimizing the Removal of Medium-Weight Uremic Toxins and Beyond

Dialysis treatment has improved the survival of patients with kidney failure. However, the hospitalization and mortality rates remain alarmingly high, primarily due to incomplete uremic toxin elimination. High-volume hemodiafiltration (HDF) has emerged as a promising approach that significantly improves patient outcomes by effectively eliminating medium and large uremic toxins, which explains its increasing adoption, particularly in Europe and Japan. Interest in this therapy has grown following the findings of the recently published CONVINCE study, as well as the need to understand the mechanisms behind the benefits. This comprehensive review aims to enhance the scientific understanding by explaining the underlying physiological mechanisms that contribute to the positive effects of HDF in terms of short-term benefits, like hemodynamic tolerance and cardiovascular disease. Additionally, it explores the rationale behind the medium-term clinical benefits, including phosphorus removal, the modulation of inflammation and oxidative stress, anemia management, immune response modulation, nutritional effects, the mitigation of bone disorders, neuropathy relief, and amyloidosis reduction. This review also analyzes the impact of HDF on patient-reported outcomes and mortality. Considering the importance of applying personalized uremic toxin removal strategies tailored to the unique needs of each patient, high-volume HDF appears to be the most effective treatment to date for patients with renal failure. This justifies the need to prioritize its application in clinical practice, initially focusing on the groups with the greatest potential benefits and subsequently extending its use to a larger number of patients.

Model-Informed Precision Dosing of Vancomycin in Adult Patients Undergoing Hemodialysis

Model-informed precision dosing (MIPD) maximizes the probability of successful dosing in patients undergoing hemodialysis. In these patients, area under the concentration-time curve (AUC)-guided dosing is recommended for vancomycin. However, this model is yet to be developed. The purpose of this study was to address this issue. The overall mass transfer-area coefficient (KoA) was used for the estimation of vancomycin hemodialysis clearance. A population pharmacokinetic (popPK) model was developed, resulting in a fixed-effect parameter for nonhemodialysis clearance of 0.316 liters/h. This popPK model was externally evaluated, with a resulting mean absolute error of 13.4% and mean prediction error of -0.17%. KoA-predicted hemodialysis clearance was prospectively evaluated for vancomycin (n = 10) and meropenem (n = 10), with a correlation equation being obtained (slope of 1.099, intercept of 1.642; r = 0.927, P < 0.001). An experimental evaluation using an in vitro hemodialysis circuit validated the developed model of KoA-predicted hemodialysis clearance using vancomycin, meropenem, vitamin B6, and inulin in 12 hemodialysis settings. This popPK model indicated a maximum a priori dosing for vancomycin-a loading dose of 30 mg/kg, which achieves the target AUC for 24 h after first dose with a probability of 93.0%, ensured by a predialysis concentration of >15 μg/mL. Maintenance doses of 12 mg/kg after every hemodialysis session could achieve the required exposure, with a probability of 80.6%. In conclusion, this study demonstrated that KoA-predicted hemodialysis clearance may lead to an upgrade from conventional dosing to MIPD for vancomycin in patients undergoing hemodialysis.

Brazilian Dialysis Survey 2021

INTRODUCTION

The Brazilian Dialysis Survey (BDS) is an important source of national data about people on chronic dialysis that contributes to the formulation of health policies regarding kidney failure.

OBJECTIVE

To report the 2021 epidemiological data from the BDS of the Brazilian Society of Nephrology (BSN).

METHODS

A survey was carried out in Brazilian chronic dialysis centers using an online questionnaire covering clinical and epidemiological aspects of patients in chronic dialysis, data on dialysis therapy, characteristics of dialysis centers, and the impact of the COVID-19 pandemic of 2021.

RESULTS

Thirty percent (n = 252) of the centers answered the questionnaire. In July 2021, the estimated total number of patients on dialysis was 148,363. The estimated prevalence and incidence rates of patients per million population (pmp) were 696 and 224, respectively. Of the prevalent patients, 94.2% were on hemodialysis (HD) (1.8% of these on hemodiafiltration), and 5.8% on peritoneal dialysis (PD); 21% were on the transplant waiting list. The incidence rate of confirmed COVID-19 between January and July 2021 was 1,236/10,000 dialysis patients, and the case-fatality rate reached 25.5%. Up to July 2021, 88.6% of patients had received at least one dose of the anti-SARS-CoV-2 vaccine. The estimated overall and COVID-19 crude annual mortality rates were 22.3% and 5.3%, respectively.

CONCLUSION

The absolute number and the prevalence rate of patients on chronic dialysis continue to increase. Most dialysis patients were vaccinated against COVID-19 during the year. The COVID-19 pandemic was associated to the overall mortality rate.

Hemodiafiltration: Technical and Medical Insights

Despite the significant medical and technical improvements in the field of dialytic renal replacement modalities, morbidity and mortality are excessively high among patients with end-stage kidney disease, and most interventional studies yielded disappointing results. Hemodiafiltration, a dialysis method that was implemented in clinics many years ago and that combines the two main principles of hemodialysis and hemofiltration-diffusion and convection-has had a positive impact on mortality rates, especially when delivered in a high-volume mode as a surrogate for a high convective dose. The achievement of high substitution volumes during dialysis treatments does not only depend on patient characteristics but also on the dialyzer (membrane) and the adequately equipped hemodiafiltration machine. The present review article summarizes the technical aspects of online hemodiafiltration and discusses present and ongoing clinical studies with regards to hard clinical and patient-reported outcomes.

Middle-size molecule clearance as measured by β2-microglobulin in high-flux versus low-flux dialysis and hemodiafiltration: A prospective randomized controlled trial

BACKGROUND

Whereas most studies to date have mainly concentrated on the comparison between high-flux hemodialysis (HFHD) and hemodiafiltration (HDF), or HFHD and low-flux hemodialysis (LFHD) in relation to the clearance of β2-microglobulin (β2M) in HD patients, there have been few related to combined HFHD and HDF therapy. To compare the clearance of middle-sized molecules as measured by β2M in HFHD versus LFHD and HDF.

METHODS

A prospective, single-center, open-label, observer-blinded, randomized controlled trial was conducted at the West China Hospital of Sichuan University in China. Patients received either HFHD or LFHD and HDF 3 times a week with follow-ups at one and 3 months. The primary endpoint was the clearance of β2M at 3 months. The secondary endpoints included hemodialysis-related adverse events, changes in anemia, states of nutrition, and inflammatory indices.

RESULTS

After 3 months of treatment, the HFHD+HDF group achieved a higher satisfaction level than the LFHD+HDF group, with decreased serum β2M concentrations (34.493 ± 7.257 vs. 43.593 ± 9.036 mg/L, p < 0.001) and elevated red blood cell counts (3.959 ± 0.742 vs. 3.602 ± 0.578 × 10¹² /L, p = 0.015). Compared with baseline, both kinds of treatment led to increases in serum urea (t = -3.623, p = 0.001 vs. t = -4.240, p < 0.001), cholesterol (t = -2.511, p = 0.016 vs. t = -4.472, p < 0.001), and magnesium (t = -2.648, p = 0.011 vs. t = -3.561, p = 0.001). An elevated level of serum albumin (t = -2.683, p = 0.010) was observed only in the HFHD+HDF group.

CONCLUSIONS

Combined therapy with HFHD and HDF has a beneficial effect on improving β2M clearance, red blood cell management, and nutrition status in HD patients.

Assessment of the Influence of Asymmetric Triacetate Cellulose Membrane on the Rate of Removal of Middle Molecular Weight Uremic Toxins in Patients Treated with Postdilution Online Hemodiafiltration

BACKGROUND: Postdilution online hemodiafiltration (OL-HDF) effectively removes uremic toxins of middle molecular weight from the blood of patients with end-stage chronic kidney disease. The rate of removal of uremic toxins depends on the type of dialysis membrane, blood flow rate (Qb), net ultrafiltration flow rate (Qnuf), and total convective volume (Vconv). AIM: The aim of this study was to examine the efficacy of asymmetric triacetate cellulose dialysis membrane in patients on post-dilution OL-HDF. METHODS: Thirty-five patients treated with post-dilution OL-HDF hemodiafiltration for at least 3 months were examined. The main parameters for assessing the efficiency of removal of uremic toxins of middle molecular weight are the concentration of β2-microglobulin (β2-M) and interleukin-6 (IL-6) in serum before and after a single session of post-dilution OL-HDF. The followings were used for statistical analysis: Kolmogorov–Smirnov test, Student’s T test for bound samples and Wilcoxon test. RESULTS: The average Vconv was 20.90 ± 3.30 liters/session. The β2-M reduction index during a single session of postdilution OL-HDF was 71.10 ± 6.39%, the IL-6 reduction index was 43.75 ± 15.60%, and the albumin reduction index was 4.55 ± 2.31%. CONCLUSION: The asymmetric triacetate cellulose dialysis membrane effectively removes β2-M and IL-6 during a single session of postdilution OL-HDF. The β2-M reduction index is ∼70%, the IL-6 reduction index is ∼40%, and albumin loss is <4.0 g/4 h. The examined dialysis membrane and dialysis modality prevent the development of amyloidosis associated with dialysis, microinflammation and reduce the risk of developing atherosclerotic cardiovascular diseases in the population of patients treated with regular hemodiafiltration.

Censo Brasileiro de Diálise 2021

RESUMO Introdução: O Censo Brasileiro de Diálise (CBD) constitui importante fonte de dados nacionais sobre pessoas em diálise crônica que contribui para a formulação de políticas de saúde. Objetivo: Relatar dados epidemiológicos de 2021 do CBD da Sociedade Brasileira de Nefrologia (SBN). Métodos: Realizou-se pesquisa em centros brasileiros de diálise crônica utilizando questionário online abrangendo aspectos clínicos e epidemiológicos de pacientes em diálise crônica, dados sobre terapia dialítica, características dos centros de diálise e o impacto da pandemia COVID-19 em 2021. Resultados: Trinta por cento (n = 252) dos centros responderam ao questionário. Em Julho de 2021, o número total estimado de pacientes em diálise foi 148.363. As taxas estimadas de prevalência e incidência de pacientes por milhão da população (pmp) foram 696 e 224, respectivamente. Dos pacientes prevalentes, 94,2% estavam em hemodiálise (HD) (1,8% destes em hemodiafiltração), e 5,8% em diálise peritoneal (DP); 21% estavam na lista de espera para transplante. A taxa de incidência de COVID-19 confirmada entre Janeiro e Julho de 2021 foi 1.236/10.000 pacientes em diálise, e a taxa de letalidade atingiu 25,5%. Até Julho de 2021, 88,6% dos pacientes haviam recebido pelo menos uma dose da vacina anti-SARS-CoV-2. As taxas estimadas de mortalidade bruta anual geral e por COVID-19 foram de 22,3% e 5,3%, respectivamente. Conclusão: O número absoluto e a taxa de prevalência de pacientes em diálise crônica continuam aumentando. A maioria dos pacientes em diálise foram vacinados contra COVID-19 durante o ano. A pandemia COVID-19 contribuiu com a taxa de mortalidade geral.

Water-Soluble Vitamins and Trace Elements Losses during On-Line Hemodiafiltration

Maintenance hemodialysis induces water-soluble vitamins and trace elements losses, which is why recommendations regarding potential supplementation were provided, but mainly based on conventional hemodialysis. This study′s aim was to measure the water–soluble vitamins and trace element losses during one on-line post-dilution hemodiafiltration (HDF) session. Thirty-nine patients under maintenance HDF were enrolled. We used the Theraflux^® sampler (Theradial Corp., Orvault, France) to analyze the full session dialysate mass transfer. Blood and dialysate samples were collected before and after one HDF session to measure B1, B2, B6, B9, B12, C vitamins, zinc, and selenium concentrations. Values significantly decreased for B1 (20.2%), B2 (13%), B6 (25.4%), B9 (32.6%), C (66.6%) and selenium (6.7%). No significant differences were found for vitamin B12 and zinc. The dialysate losses per session were 1.12 ± 0.88 mg for vitamin B1, 0.28 ± 0.30 mg for B2, 0.33 ± 0.09 mg for B6, 0.3 ± 0.18 mg for B9, 147.5 ± 145.50 mg for C and 25.75 ± 6.91 mg for zinc. Vitamin B12 and selenium were under detection values. In conclusion, during a standard 4hr-HDF session, we found important losses for vitamin B1, B6, B9, C and zinc, suggesting the need for regular monitoring of plasma levels and systematic supplementation of these compounds.

Coping Strategies in End-Stage Renal Disease Patients on Hemodialysis in Oman: Optimistic, Supportive, Confrontive, and Prayerful

Hemodialysis (HD) treatment is highly inflexible for individuals with end-stage renal disease (ESRD). Effective use of coping strategies can help to improve their performance and health outcomes. The purpose of this study was to understand the coping strategies used by patients on HD and their perceived helpfulness in Oman. A cross-sectional study was conducted to identify coping strategies among patients on HD. Participants on HD (N = 157) were enrolled from two HD centers in Oman. The results revealed that the most commonly used coping strategies were optimistic, confrontive, and supportive, and the most commonly helpful were optimistic, supportive, and confrontive. Prayer and trust in God was the most commonly used and most helpful coping strategies. The current study has identified the most common strategies used and found effective by Omani patients in coping with ESRD and HD. Identifying these coping mechanisms may help healthcare providers support this group of patients and improve their quality of care.

Improving Solute Clearances by Hemodialysis

The adequacy of hemodialysis is now assessed by measuring the removal of the single-solute urea. The urea clearance provided by contemporary dialysis is a large fraction of the blood flow through the dialyzer and therefore cannot be increased much further. Other solutes however likely contribute more than urea to the residual uremic illness suffered by hemodialysis patients. We here review methods which could be employed to increase the clearance of nonurea solutes. We will separately consider the clearances of free low-molecular-mass solutes, free larger solutes, and protein-bound solutes. New clinical studies will be required to test the extent to which increasing the clearance on nonurea solutes with these various characteristics can improve patients' health.

Hemodiafiltration in developing countries

Hemodiafiltration (HDF) is a promising kidney replacement therapy modality for patients with end-stage kidney disease. The principle of uremic toxin clearance by combining convection and diffusion can lead to greater benefits compared to conventional hemodialysis. Evidence is building that supports the advantages of HDF with short-term outcomes such as greater intradialytic hemodynamic stability, improved nutritional status, attenuation of anemia, and reduction of inflammatory cytokines which produce improved key long-term impacts including survival and cardiovascular outcomes. Very little is known about the prevalence of HDF treatments in developing countries due to a shortage of national kidney registries. HDF experience is limited in many countries due to the cost of dialysis treatments, availability of online HDF machines, and reimbursement policies. These obstacles have led to nephrologists developing innovations, for example, convective control HDF (CC-HDF), simple mid-dilution, and simple mixed-dilution methods, which may be as effective as commercially available HDF machines. In this article, we will focus on the experience of HDF practice and barriers to adoption in developing countries. Results can guide clinical practice recommendations for implementing HDF in resource-limited settings.

The rationale and clinical potential of on-line hemodiafiltration as renal replacement therapy

On-line hemodiafiltration (ol-HDF) was developed in the 1980s in response to the unmet medical needs observed with conventional low- and high-flux hemodialysis. Firstly, the limited overall efficacy of conventional HD treatment programs as compared to native kidney function has been consistently documented over the broad MW spectrum of uremic toxins as well as fluid volume and hemodynamic control. Secondly, the unphysiological profile of intermittent treatment leading to repetitive dialysis-induced hemodynamic stress is now a well-recognized component of cardiovascular disease and end organ damage. Thirdly, the bioincompatibility of patient-dialysis system leading to dialysis-induced biological reactions also identified as contributing to dialytic morbidity and mortality. To overcome these limitations and pitfalls, alternative convective-based therapies (hemofiltration and hemodiafiltration), using higher hemoincompatible membranes and ultrapure dialysis fluid, were proposed as a solution to enhance and enlarge MW spectrum of uremic compounds cleared and to reduce dialysis-patient biological interactions. In this context, online HDF appeared soon as the best viable and efficient renal replacement modality to cover these needs. Clinical development and implementation of ol-HDF showed also that dialytic convective dose matters with a threshold point (23 L/1.73 m² in postdilution mode) to observe clinical benefits and outcomes improvements.

Switching from high-flux dialysis to hemodiafiltration: Cost-consequences for patients, providers, and payers

Hemodiafiltration (HDF) achieves a more efficient reduction of the uremic toxic load compared to standard high-flux hemodialysis (HF-HD) by virtue of the combined diffusive and convective clearances of a broad spectrum of uremic retention solutes. Clinical trials and registry data suggest that HDF improves patient outcomes. Despite the acknowledged need to improve survival rates of dialysis patients and the survival benefit HDF offers, there is little to no utilization in some countries (such as the US) in prescribing HDF to their patients. In this analysis, we present the healthcare value-based case for HDF (relative to HF-HD) from the patient, provider, and payor perspectives. The improved survival and reduced morbidity observed in studies conducted outside the US, as well as the reduced hospitalization, are attractive for each stakeholder. We also consider the potential barriers to greater utilization of HDF therapies, including unfounded concerns regarding additional costs of HDF, e.g., for the preparation and microbial testing of quality of substitution fluids. Ultrapure fluids are easily attainable and prepared from dialysis fluids using established "online" (OL) technologies. OL-HDF has matured to a level whereby little additional effort is required to safely implement it as all modern machine systems are today equipped with the OL-HDF functionality. Countries already convinced of the advantages of HF-HD are thus well positioned to make the transition to OL-HDF to achieve further clinical and associated economic benefits. Healthcare systems struggling to cope with the increasing demand for HD therapies would therefore, like patients, be beneficiaries in the long term with increased usage of OL-HDF for end stage kidney disease patients.

High volume online post-dilution hemodiafiltration: how relevant is it in chronic kidney disease?

Online hemodiafiltration is potentially a superior mode of dialysis compared to conventional hemodialysis. However, prospective randomized controlled trials have failed to demonstrate such superiority. Post-hoc analyses of these trials have indicated that high volume post-dilution hemodiafiltration is associated with lower death rates than conventional dialysis. This study discusses whether the lower death rates ascribed to high volume hemodiafiltration are linked to convection volume or the time on dialysis needed to achieve high convection volumes.

CONVINCE in the context of existing evidence on haemodiafiltration

Haemodiafiltration (HDF) provides a greater removal of larger solutes and protein-bound compounds than conventional high-flux haemodialysis (HD). There are indications that the patients receiving the highest convection volumes of HDF result in an improved survival compared with HD. However, the comparative efficacy of HDF vs HD remains unproven. Here we provide a comparative account of the methodology and aims of ‘the comparison of high-dose HDF with high-flux HD’ (CONVINCE) study in the context of the totality of evidence and how this study will contribute to reaching a higher level of certainty regarding the comparative efficacy of HDF vs HD in people with end-stage kidney disease (ESKD).

Choices in hemodialysis therapies: variants, personalized therapy and application of evidence-based medicine

The extent of removal of the uremic toxins in hemodialysis (HD) therapies depends primarily on the dialysis membrane characteristics and the solute transport mechanisms involved. While designation of ‘flux’ of membranes as well toxicity of compounds that need to be targeted for removal remain unresolved issues, the relative role, efficiency and utilization of solute removal principles to optimize HD treatment are better delineated. Through the combination and intensity of diffusive and convective removal forces, levels of concentrations of a broad spectrum of uremic toxins can be lowered significantly and successfully. Extended clinical experience as well as data from several clinical trials attest to the benefits of convection-based HD treatment modalities. However, the mode of delivery of HD can further enhance the effectiveness of therapies. Other than treatment time, frequency and location that offer clinical benefits and increase patient well-being, treatment- and patient-specific criteria may be tailored for the therapy delivered: electrolytic composition, dialysate buffer and concentration and choice of anticoagulating agent are crucial for dialysis tolerance and efficacy. Evidence-based medicine (EBM) relies on three tenets, i.e. clinical expertise (i.e. doctor), patient-centered values (i.e. patient) and relevant scientific evidence (i.e. science), that have deviated from their initial aim and summarized to scientific evidence, leading to tyranny of randomized controlled trials. One must recognize that practice patterns as shown by Dialysis Outcomes and Practice Patterns Study and personalization of HD care are the main driving force for improving outcomes. Based on a combination of the three pillars of EBM, and particularly on bedside patient–clinician interaction, we summarize what we have learned over the last 6 decades in terms of best practices to improve outcomes in HD patients. Management of initiation of dialysis, vascular access, preservation of kidney function, selection of biocompatible dialysers and use of dialysis fluids of high microbiological purity to restrict inflammation are just some of the approaches where clinical experience is vital in the absence of definitive scientific evidence. Further, HD adequacy needs to be considered as a broad and multitarget approach covering not just the dose of dialysis provided, but meeting individual patient needs (e.g. fluid volume, acid–base, blood pressure, bone disease metabolism control) through regular assessment—and adjustment—of a series of indicators of treatment efficiency. Finally, in whichever way new technologies (i.e. artificial intelligence, connected health) are embraced in the future to improve the delivery of dialysis, the human dimension of the patient–doctor interaction is irreplaceable. Kidney medicine should remain ‘an art’ and will never be just ‘a science’.

Why and how high volume hemodiafiltration may reduce cardiovascular mortality in stage 5 chronic kidney disease dialysis patients? A comprehensive literature review on mechanisms involved

Online hemodiafiltration (HDF) is an established renal replacement modality for patients with end stage chronic kidney disease that is now gaining rapid clinical acceptance worldwide. Currently, there is a growing body of evidence indicating that treatment with HDF is associated with better outcomes and reduced cardiovascular mortality for dialysis patients. In this comprehensive review, we provide an update on the potential mechanisms which may improve survival in HDF treated patients. The strongest evidence is for better hemodynamic stability and reduced endothelial dysfunction associated with HDF treatments. Clinically, this is marked by a reduced incidence of intradialytic hypotensive episodes, with a better hemodynamic response to ultrafiltration, mediated by an increase in total peripheral vascular resistance and extra-vascular fluid recruitment, most likely driven by the negative thermal balance associated with online HDF therapy. In addition, endothelial function appears to be improved due to a combination of a reduction of the inflammatory and oxidative stress complex syndrome and exposure to circulating cardiovascular uremic toxins. Reports of reversed cardiovascular remodeling effects with HDF may be confounded by volume and blood pressure management, which are strongly linked to center clinical practices. Currently, treatment with HDF appears to improve the survival of dialysis patients predominantly due to a reduction in their cardiovascular burden, and this reduction is linked to the sessional convection volume exchanged.

Changes in practice patterns in Japan from before to after JSDT 2013 guidelines on hemodialysis prescriptions: results from the JDOPPS

BACKGROUND

The Japanese Society for Dialysis Therapy (JSDT) published in 2013 inaugural hemodialysis (HD) guidelines. Specific targets include 1.4 for single-pool Kt/V (spKt/V) with a minimum dose of 1.2, minimum dialysis session length of 4 hours, minimum blood flow rate (BFR) of 200 mL/min, fluid removal rate no more than 15 mL/kg/hr, and hemodiafiltration (HDF) therapy for certain identified symptoms. We evaluated the effect of these guidelines on actual practice in the years spanning 2005 - 2018.

METHODS

Analyses were carried out to describe trends in the above HD prescription practices from December 2005 to April 2013 (before guideline publication) to August 2018 based on prevalent patient cross-sections from approximately 60 randomly selected HD facilities participating in the Japan Dialysis Outcomes and Practice Patterns Study.

RESULTS

From April 2006 to August 2017 continual rises occurred in mean spKt/V (from 1.35 to 1.49), and percent of patients having spKt/V>1.2 (71% to 85%). Mean BFR increased with time from 198.3 mL/min (April 2006) to 218.4 mL/min (August 2017) , along with percent of patients with BFR >200 ml/min (65% to 85%). HDF use increased slightly from 6% (April 2006 and August 2009) to 8% by April 2013, but increased greatly thereafter to 23% by August 2017. In contrast, mean HD treatment time showed little change from 2006-2017, whereas mean UFR declined from 11.3 in 2006 to 8.4 mL/Kg/hour in 2017.

CONCLUSIONS

From 2006 - 2018 Japanese HD patients experienced marked improvement in reaching the spKt/V target specified by the 2013 JSDT guidelines. This may have been due to moderate increase in mean BFR even though mean HD session length did not change much. In addition, HDF use increased dramatically in this time period. Other HD delivery changes during this time, such as increased use of super high flux dialyzers, also merit study. While we cannot definitively conclude a causal relationship between the publication of the guidelines and the subsequent practice changes in Japan, those changes moved practice closer to the recommendations of the guidelines.

Development of online hemodiafiltration in Japan

Evidence concerning online hemodiafiltration (ol-HDF) includes increased uremic toxin removal, prevention of dialysis-related hypotension, improved survival, and recovery of dialysis-related uncertain symptoms. In particular, evidence has been shown regarding prevention of dialysis hypotension and improvement of survival, but the mechanism of its manifestation is still unclear and its effects themselves are questionable. In Japan, pre dilution ol-HDF is mainly performed, and improvement in survival rate has been shown on the condition of convection volume is 40 L/session or more. In particular, the removal of α1-microglubulin (αMG), which is a medium-middle solute, is targeted. The antioxidant action (Heme Scavenger) of αMG, is presumed, but in dialysis patients, the majority in serum are deteriorated (oxidized) αMG. It has been pointed out that removing the deteriorated αMG by ol-HDF may produce new αMG from the liver and lead to recovery of the original antioxidant effect. However, clinical evidence of this mechanism is desired. Obtaining evidence for the indicated αMG removal activity of ol-HDF will lead to advancement in HDF.

Commentary on the NICE guideline on renal replacement therapy and conservative management

NICE Guideline NG107, “Renal replacement therapy and conservative management” (Renal replacement therapy and conservative management (NG107); 2018:1–33) was published in October 2018 and replaced the existing NICE guideline CG125, “Chronic Kidney Disease (Stage 5): peritoneal dialysis” (Chronic kidney disease (stage 5): peritoneal dialysis | Guidance | NICE; 2011) and NICE Technology Appraisal TA48, “Guidance on home compared with hospital haemodialysis for patients with end-stage renal failure”(Guidance on home compared with hospital haemodialysis for patients with end-stage renal failure (Technology appraisal guideline TA48); 2002) The aim of the NICE guideline (NG107) was to provide guidance on renal replacement therapy (RRT), including dialysis, transplant and conservative care, for adults and children with CKD Stages 4 and 5. The guideline is extremely welcomed by the Renal Association and it offers huge value to patients, clinicians, commissioners and key stakeholders. It overlaps and enhances current guidance published by the Renal Association including “Haemodialysis” (Clinical practice guideline: Haemodialysis; 2019) which was updated in 2019 after the publication of the NICE guideline, “Peritoneal Dialysis in Adults and Children” (Clinical practice guideline: peritoneal Dialysis in adults and children; 2017) and “Planning, Initiation & withdrawal of Renal Replacement Therapy” (Clinical practice guideline: planning, initiation and withdrawal of renal replacement therapy; 2014) (at present there are no plans to update this guideline).

There are several strengths to NICE guideline NG107 and we agree with and support the vast majority of recommendation statements in the guideline. This summary from the Renal Association discusses some of the key highlights, controversies, gaps in knowledge and challenges in implementation. Where there is disagreement with a NICE guideline statement, we have highlighted this and a new suggested statement has been written.

Improving Clearance for Renal Replacement Therapy

The adequacy of hemodialysis is now assessed by measuring the removal of a single solute, urea. The urea clearance provided by current dialysis methods is a large fraction of the blood flow through the dialyzer, and, therefore, cannot be increased much further. However, other solutes, which are less effectively cleared than urea, may contribute more to the residual uremic illness suffered by patients on hemodialysis. Here, we review a variety of methods that could be used to increase the clearance of such nonurea solutes. New clinical studies will be required to test the extent to which increasing solute clearances improves patients' health.

Achieving high convective volume in hemodiafiltration: Lessons learned after successful implementation in the HDFit trial

BACKGROUND AND OBJECTIVES

High-volume online hemodiafiltration (OL-HDF) associates with improved outcomes compared to hemodialysis (HD), provided adequate dosing is achieved as estimated from convective volume (CV). Achievement of high CV and its impact on biochemical indicators following a standardized protocol converting HD patients to OL-HDF has not been systematically reported. We assessed the success of implementation of OL-HDF in clinics naïve to the modality.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We analyzed the results of the implementation of postdilution OL-HDF in patients randomized to the HDF arm of a clinical trial (impact of hemoDiaFIlTration on physical activity and self-reported outcomes: a randomized controlled trial (HDFit) trial [ClinicalTrials.gov:NCT02787161]). The day before randomization of the first patient to OL-HDF at each clinic staff started a 3-day in-person training module on operation of Fresenius 5008 CorDiax machine in HDF mode. Patients were converted from high-flux HD to OL-HDF under oversight of trainers. OL-HDF was performed over a 6-months follow-up with a CV target of 22 L/treatment. We characterized median achieved CV >22 L/treatment record and analyzed the impact of HDF on biochemical variables.

RESULTS

Ninety-seven patients (mean age 53 ± 16 years, 29% with diabetes, and 11% had a catheter) from 13 clinics randomized to the OL-HDF arm of the trial were converted from HD to HDF. Median CV > 22 L/treatment was achieved in 99% (94/95) of OL-HDF patients throughout follow-up. Monthly mean CV ranged from 27.1 L to 27.5 L. OL-HDF provided an increased single pool Kt/V at 3-months (0.2 [95% CI: 0.1-0.3]) and 6-months (0.2 [95% CI: 0.1-0.4]) compared to baseline, and reduced phosphate at 3-months (-0.4 mg/dL [95% CI: -0.8 to -0.12]) of follow-up.

CONCLUSIONS

High-volume online hemodiafiltration was successfully implemented with 99% of patients achieving protocol defined CV target. Monthly mean CV was consistently >22 L/treatment during follow-up. Kt/V increased, and phosphate decreased with OL-HDF. Findings resulting from a short training period in several dialysis facilities appear to suggest HDF is an easily implementable technique.

Dose recommendations for anticancer drugs in patients with renal or hepatic impairment

Renal or hepatic impairment is a common comorbidity for patients with cancer either because of the disease itself, toxicity of previous anticancer treatments, or because of other factors affecting organ function, such as increased age. Because renal and hepatic function are among the main determinants of drug exposure, the pharmacokinetic profile might be altered for patients with cancer who have renal or hepatic impairment, necessitating dose adjustments. Most anticancer drugs are dosed near their maximum tolerated dose and are characterised by a narrow therapeutic index. Consequently, selecting an adequate dose for patients who have either hepatic or renal impairment, or both, is challenging and definitive recommendations on dose adjustments are scarce. In this Review, we discuss the effect of renal and hepatic impairment on the pharmacokinetics of anticancer drugs. To guide clinicians in selecting appropriate dose adjustments, information from available drug labels and from the published literature were combined to provide a practical set of recommendations for dose adjustments of 160 anticancer drugs for patients with hepatic and renal impairment.

The renal replacement therapy landscape in 2030: reducing the global cardiovascular burden in dialysis patients

Despite the significant progress made in understanding chronic kidney disease and uraemic pathophysiology, use of advanced technology and implementation of new strategies in renal replacement therapy, the clinical outcomes of chronic kidney disease 5 dialysis patients remain suboptimal. Considering residual suboptimal medical needs of short intermittent dialysis, it is our medical duty to revisit standards of dialysis practice and propose new therapeutic options for improving the overall effectiveness of dialysis sessions and reduce the burden of stress induced by the therapy. Several themes arise to address the modifiable components of the therapy that are aimed at mitigating some of the cardiovascular risks in patients with end-stage kidney disease. Among them, five are of utmost importance and include: (i) enhancement of treatment efficiency and continuous monitoring of dialysis performances; (ii) prevention of dialysis-induced stress; (iii) precise handling of sodium and fluid balance; (iv) moving towards heparin-free dialysis; and (v) customizing electrolyte prescriptions. In summary, haemodialysis treatment in 2030 will be substantially more personalized to the patient, with a clear focus on cardioprotection, volume management, arrhythmia surveillance, avoidance of anticoagulation and the development of more dynamic systems to align the fluid and electrolyte needs of the patient on the day of the treatment to their particular circumstances.