Effects of high-volume online mixed-hemodiafiltration on anemia management in dialysis patients

Hemoincompatibility in Hemodialysis-Related Therapies and Their Health Economic Perspectives

Hemobiologic reactions associated with the hemoincompatibility of extracorporeal circuit material are an undesirable and inevitable consequence of all blood-contacting medical devices, typically considered only from a clinical perspective. In hemodialysis (HD), the blood of patients undergoes repetitive (at least thrice weekly for 4 h and lifelong) exposure to different polymeric materials that activate plasmatic pathways and blood cells. There is a general agreement that hemoincompatibility reactions, although unavoidable during extracorporeal therapies, are unphysiological contributors to non-hemodynamic dialysis-induced systemic stress and need to be curtailed. Strategies to lessen the periodic and direct effects of blood interacting with artificial surfaces to stimulate numerous biological pathways have focused mainly on the development of 'more passive' materials to decrease intradialytic morbidity. The indirect implications of this phenomenon, such as its impact on the overall delivery of care, have not been considered in detail. In this article, we explore, for the first time, the potential clinical and economic consequences of hemoincompatibility from a value-based healthcare (VBHC) perspective. As the fundamental tenet of VBHC is achieving the best clinical outcomes at the lowest cost, we examine the equation from the individual perspectives of the three key stakeholders of the dialysis care delivery processes: the patient, the provider, and the payer. For the patient, sub-optimal therapy caused by hemoincompatibility results in poor quality of life and various dialysis-associated conditions involving cost-impacting adjustments to lifestyles. For the provider, the decrease in income is attributed to factors such as an increase in workload and use of resources, dissatisfaction of the patient from the services provided, loss of reimbursement and direct revenue, or an increase in doctor-nurse turnover due to the complexity of managing care (nephrology encounters a chronic workforce shortage). The payer and healthcare system incur additional costs, e.g., increased hospitalization rates, including intensive care unit admissions, and increased medications and diagnostics to counteract adverse events and complications. Thus, hemoincompatibility reactions may be relevant from a socioeconomic perspective and may need to be addressed beyond just its clinical relevance to streamline the delivery of HD in terms of payability, future sustainability, and societal repercussions. Strategies to mitigate the economic impact and address the cost-effectiveness of the hemoincompatibility of extracorporeal kidney replacement therapy are proposed to conclude this comprehensive approach.

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.

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.

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.

Mixed versus predilution hemodiafiltration effects on convection volume and small and middle molecule clearance in hemodialysis patients: a prospective randomized controlled trial

Background

The use of newly developed mixed-dilution hemodiafiltration (HDF) can supplement the weaknesses of pre- and postdilution HDF. However, it is unclear whether mixed-HDF performs well compared to predilution HDF.

Methods

We conducted a prospective, open-labeled, randomized controlled trial from two hemodialysis centers in Korea. Between January 2017 and September 2019, 60 patients who underwent chronic hemodialysis were randomly assigned at a 1:1 ratio to receive either predilution HDF (n = 30) or mixed-HDF (n = 30) for 6 months. We compared convection volume, changes in small- and medium-sized molecule clearance, high-sensitive C-reactive protein (hs-CRP) level, and dialysis-related parameters between the two dialysis modalities.

Results

A mean effective convection volume of 41.0 ± 10.3 L/session in the predilution HDF group and 51.5 ± 9.0 L/session in the mixed-HDF group was obtained by averaging values of three time-points. The difference in effective convection volume between the groups was 10.5 ± 1.3 L/session. This met the preset noninferiority criteria, suggesting that mixed-HDF was noninferior to predilution HDF. Moreover, the β2-microglobulin reduction rate was greater in the mixed-HDF group than in the predilution HDF group, while mixed-HDF provided greater transmembrane pressure. There were no significant between-group differences in Kt/V urea levels, changes in predialysis hs-CRP levels, proportions of overhydration, or blood pressure values. Symptomatic intradialytic hypotension episodes and other adverse events occurred similarly in the two groups.

Conclusion

Use of mixed-HDF was comparable to predilution HDF in terms of delivered convection volume and clinical parameters. Moreover, mixed-HDF provided better β2-microglobulin clearance than predilution HDF.

High-volume online haemodiafiltration treatment and outcome of end-stage renal disease patients: more than one mode

The reduction of the dismally high mortality of current end-stage renal disease patients maintained on conventional standard haemodialysis (HD) remains an unmet medical need. Online haemodiafiltration (HDF) modes with various sites of fluid substitution (post-, pre-, mixed- and mid-dilution) are increasingly used worldwide as promising alternatives to conventional HD. Large scale cohort studies, post hoc analyses of randomized trials, and individual participant meta-analyses suggest that post-dilution and pre-dilution, especially with high substitution volumes, improve outcomes compared with conventional standard HD. However, there is no definitive proof of a survival advantage of HDF over standard HD. The different modes of high-volume HDF should be considered a therapeutic platform allowing to personalize and tailor routine HDF treatment. The selection of the HDF mode should be made according to individual patient characteristics. Utilizing high retention onset membranes, expanded haemodialysis (HDx) can achieve the same solute removal performance as HDF. Subgroups of high-volume OL-HDF patients could benefit from HDx. Ongoing and future trials should provide definitive proof for the superiority of high-volume OL-HDF over conventional HD or HDx to give guidance for the most favourable mode of dialytic therapy for clinical use.

The production of on-line dialysis water for extracorporeal dialysis: proposals for an increased safety upgrade: a viewpoint

INTRODUCTION

At the start of the 2000s, the progressive diffusion of high-flux extracorporeal dialysis and membranes saw an increased use of high infusion volumes injected into the patient's blood circuit following the advent of on-line water production plants.

METHODOLOGY

Our 15-year experience with on-line extracorporeal methodologies using very high infusion volumes has led to the detection of errors and weaknesses, thus allowing us to correct and provide for the implementation of appropriate technology in dialysis water production plants with the aim of ensuring a higher chemical-physical, bacteriological and endotoxin quality. The initial procedures had already been outlined in the 2005 Italian Guidelines, although still today Health Technicians and Nephrologists operating in the field are unable to take on board specific integrations for on-line methods due to a lack of upgrading of documentation in both European and non-European Guidelines.

RESULTS

After more than 17 years' experience, and in view of the technological implementations developed since 2005, we wish to put forward a series of suggestions in an attempt to improve the safety of on-line water, with uses ranging from drinking water, pre-treatment, osmosis, distribution circuit, hemodialysis monitors up to the most recent update of microbiological cultures.

DISCUSSION

Additional, more stringent measures are required to prevent the occurrence of acute accidents during dialysis sessions and to reduce chronic inflammation-oxidation deriving from the use of not totally ultra-pure/sterile dialysis fluids.

CONCLUSION

Our point of view based on our long-standing experience, the proposals made relate to procedures to be applied in technological maintenance, which the consultant nephrologist and other relevant personnel such as microbiologists, biologists, and technical operators should adhere to rigorously to ensure that the production of dialysis water on-line is viewed on a par with a pharmacological administration.

Mixed hemodiafiltration reduces erythropoiesis stimulating agents requirement in dialysis patients: a prospective randomized study

BACKGROUND

Improved responsiveness to erythropoiesis stimulating agents (ESAs) in patients on on-line post-dilution hemodiafiltration (Post-HDF) compared with conventional hemodialysis (HD) was reported by some authors but challenged by others. This prospective, cross-over randomized study tested the hypothesis that an alternative infusion modality of HDF, mixed-dilution HDF (Mixed HDF), could further reduce ESAs requirement in dialysis patients compared to the traditional Post-HDF.

METHODS

One-hundred-twenty prevalent patients from 6 Dialysis Centers were randomly assigned to two six-months treatment sequences: A-B and B-A (A, Mixed HDF; B, Post-HDF). Primary outcome was comparative evaluation of ESA (darbepoetin alfa) requirement and ESA resistance. Treatments efficiency, iron and vitamins status, inflammation and nutrition parameters were monitored.

RESULTS

In sequence A, darbepoetin requirement decreased during Mixed HDF from 29.5 to 23.7 µg/month and increased significantly during Post-HDF (32.3 µg/month at 6th month) while, in sequence B, it increased during Post-HDF from 38.2 to 43.7 µg/month and decreased during Mixed HDF (23.9 µg/month at 6th month). Overall, EPO doses at 6 months on Mixed and Post-HDF were 23.8 and 38.4 µg/month, respectively, P < 0.01. A multiple linear model confirmed that Mixed HDF vs Post-HDF reduced significantly ESA requirement and ESA resistance (P < 0.0001), by a mean of 29% (CI 23-35%) in the last three months of the observation periods.

CONCLUSIONS

Mixed HDF decreased darbepoetin-alfa requirement in dialysis patients. This might help preventing the untoward side effects of high ESA doses, besides having a remarkable economic impact. Additional evidence is needed to confirm this potential benefit of Mixed-HDF.

The Influence of Inflammation on Anemia in CKD Patients

Anemia is frequently observed in the course of chronic kidney disease (CKD) and it is associated with diminishing the quality of a patient’s life. It also enhances morbidity and mortality and hastens the CKD progression rate. Patients with CKD frequently suffer from a chronic inflammatory state which is related to a vast range of underlying factors. The results of studies have demonstrated that persistent inflammation may contribute to the variability in Hb levels and hyporesponsiveness to erythropoietin stimulating agents (ESA), which are frequently observed in CKD patients. The understanding of the impact of inflammatory cytokines on erythropoietin production and hepcidin synthesis will enable one to unravel the net of interactions of multiple factors involved in the pathogenesis of the anemia of chronic disease. It seems that anti-cytokine and anti-oxidative treatment strategies may be the future of pharmacological interventions aiming at the treatment of inflammation-associated hyporesponsiveness to ESA. The discovery of new therapeutic approaches towards the treatment of anemia in CKD patients has become highly awaited. The treatment of anemia with erythropoietin (EPO) was associated with great benefits for some patients but not all.