High-flux Dialysis Research Articles

085 VANCOMYCIN REMOVAL IN PATIENTS ON HIGH-FLUX INTERMITTENT HEMODIALYSIS - VARELI

Category: Other Presenter: Mr ZAI YANG YONG Keywords: hemodialysis, vancomycin, high-flux High-flux dialysis membrane is commonly used nowadays and studies have shown that vancomycin is significant removed with high-flux hemodialysis (HD). Furthermore, there is a rebound of vancomycin level 3-6 hours after HD due to redistribution. In our hospital, vancomycin dosing is currently based on pre HD serum concentration of less than 20 μg/mL but this may result in under-dosing due to drug removal during high-flux HD. To determine the extent of vancomycin removal with high-flux intermittent HD. This is a prospective, observational study performed at Sarawak General Hospital, Kuching from June 2016 to May 2017. All patients on high-flux HD who received vancomycin with a trough level of more than 20 μg/mL pre HD were recruited into this study. Vancomycin levels were measured pre HD, at completion of 4 hours of HD and 6 hours after HD. The serum concentrations of vancomycin were determined by Enzyme Multiplied Immunoassay Technique (EMIT) using SIEMENS VIVA E. Data were analysed using descriptive statistics. A total of 8 patients were recruited into this study. The mean (SD) vancomycin serum concentrations pre HD, upon completion of 4-hour HD, and 6 hours post HD were 28.89 (5.03) μg/mL, 16.18 (4.35) μg/mL and 22.31 (4.97) μg/mL respectively. The extent of vancomycin removal with 4-hour high-flux HD was 44.31%, but the actual removal of vancomycin taking into consideration of rebound was 22.49% at 6 hours post HD. Three out of eight (37.5%) patients had vancomycin concentration of less than 20 μg/mL 6 hours post HD. A considerable amount of vancomycin is eliminated with high-flux HD. This should be taken into consideration if using pre HD vancomycin level to guide dosing. If feasible, vancomycin concentration 6 hours post HD would be a more accurate guide to prevent under-dosing.

Modulation of leucocytic angiotensin-converting enzymes expression in patients maintained on high-permeable haemodialysis.

High mortality of haemodialysis patients is associated with systemic chronic inflammation and overactivation of the renin-angiotensin system (RAS). Insufficient elimination of pro-inflammatory immune mediators, especially in the molecular weight range of 15-45 kDa, may be one of the reasons for this. Employment of haemodialysis membranes with increased permeability was shown to ameliorate the inflammatory response and might modulate the effects of local RAS. In this study, we tested the impact of high cut-off (HCO), medium cut-off (MCO) and high-flux (HF) dialysis on leucocytic transcripts of angiotensin-converting enzymes (ACE and ACE2). Additionally, the impact of HCO, MCO and HF sera and dialysates on local ACEs and inflammation markers was tested in THP-1 monocytes. Patients' leucocytes were obtained from our recent clinical studies comparing HCO and MCO dialysers with HF. The cells were subjected to quantitaive polymerase chain reaction (qPCR) analyses with TaqMan probes specific for ACE, ACE2 and angiotensin II (AngII) and Ang1-7 receptors. Sera and dialysates from the clinical trials as well as samples from in vitro dialysis were tested on THP-1 monocytic cells. The cells were subjected to qPCR analyses with TaqMan probes specific for ACE, ACE2, interleukin-6 and tumour necrosis factor α and immunocytochemistry with ACE and ACE2 antibodies. Leucocytes obtained from patients treated with HCO or MCO demonstrated decreased transcript expression of ACE, while ACE2 was significantly upregulated as compared with HF. Receptors for AngII and Ang1-7 remained unchanged. THP-1 monocytes preconditioned with HCO and MCO patients' or in vitro dialysis sera reflected the same expressional regulation of ACE and ACE2 as those observed in HCO and MCO leucocytes. As a complementary finding, treatment with HCO and MCO in vitro dialysates induced a pro-inflammatory response of the cells as demonstrated by elevated messenger RNA expression of tumour necrosis factor α and interleukin-6, as well as upregulation of ACE and decreased levels of ACE2. Taken together, these data demonstrate that employment of membranes with high permeability eliminates a spectrum of mediators from circulation that affect the RAS components in leucocytes, especially ACE/ACE2.

High-Flux Dialysis: Clinical, Biochemical, and Proteomic Comparison with Low-Flux Dialysis and On-Line Hemodiafiltration

Hemodiafiltration on-line (on-line HDF) is a more efficient treatment than low-flux hemodialysis (HD). Unfortunately, it cannot be proposed to all patients. The aim of this study was to evaluate the safety, efficiency, and mechanisms of removal of toxins with high-flux HD vs. low-flux HD and on-line HDF. Randomized cross-over study designed to evaluate efficiency and tolerability of high-flux HD vs. low-flux HD in aged patients; to compare by means of biochemical and proteomic analyses the efficiency and mechanisms of removal of toxins with high-flux HD vs. on-line HDF. The removal of small toxins was similar with high-flux and low-flux HD. β2-microglobulin was removed only with high-flux HD, which had an excellent tolerability. The efficiency of high-flux HD was similar to on-line HDF. Proteomic analysis demonstrated that only high-flux membranes remove and adsorb small proteins. High-flux HD may be an efficient alternative to on-line HDF.

Factors associated with uremic pruritus

Background: The etiopathogenesis of uremic pruritus (UP) is multifactorial aspect, and it is thus necessary to elucidate its associated factors to develop efficient therapeutics approaches. This study aimed to verify the prevalence of UP and its associated factors.
 Methods and Findings: Prospective and cross-sectional study with patients undergoing hemodialysis at a university public hospital. The data were obtained between April 2014 and April 2015. The statistical analysis was carried out using multivariate regression models, and statistical significance was set at p<0.05. A total of 164 patients were included, and pruritus was reported in 64 (39%). In the multivariate analysis, a higher creatinine level was risk factor for pruritus (β=1.09, 95% CI 1.00-1.19; p=0.048), as was a lower level of hemoglobin (β=0.85, 95% CI 0.73-0.99; p=0.043). Dyslipidemia (β=1.52, 95% CI 0.12-2.91; p=0.03), obesity (β=2.40, 95% CI 1.03-3.78; p=0.001), higher levels of C-reactive protein (β=0.26, 95% CI 0.19-0.34; p<0.001) and black race (β=1.49, 95% CI -2.57 and 0.42; p<0.006) were associated with a greater intensity of pruritus. The use of a high-flux dialyzer was associated with a lower intensity of pruritus (β=-1.69, 95% CI -3.05-0.34; p=0.01).
 Conclusion: Uremic pruritus has a high prevalence in hemodialysis patients, and the data suggest that the higher the creatinine and the lower the hemoglobin levels are, the greater the risk of developing pruritus is. Dyslipidemia, obesity, and higher levels of C-reactive protein were associated with a greater intensity of pruritus, whereas the use of a high-flux dialyzer was associated with lower pruritus intensity.

In Vitro Dialysis of Cytokine-Rich Plasma With High and Medium Cut-Off Membranes Reduces Its Procalcific Activity.

Recently developed high-flux (HF) dialysis membranes with extended permeability provide better clearance of middle-sized molecules such as interleukins (ILs). Whether this modulation of inflammation influences the procalcific effects of septic plasma on vascular smooth muscle cells (VSMCs) is not known. To assess the effects of high cut-off (HCO) and medium cut-off (MCO) membranes on microinflammation and in vitro vascular calcification we developed a miniature dialysis model. Plasma samples from lipopolysaccharide-spiked blood were dialyzed with HF, HCO, and MCO membranes in an in vitro miniature dialysis model. Afterwards, IL-6 concentrations were determined in dialysate and plasma. Calcifying VSMCs were incubated with dialyzed plasma samples and vascular calcification was assessed. Osteopontin (OPN) and matrix Gla protein (MGP) were measured in VSMC supernatants. IL-6 plasma concentrations were markedly lower with HCO and MCO dialysis. VSMC calcification was significantly lower after incubation with MCO- and HCO-serum compared to HF plasma. MGP and OPN levels in supernatants were significantly lower in the MCO but not in the HCO group compared to HF. In vitro dialysis of cytokine-enriched plasma samples with MCO and HCO membranes reduces IL-6 levels. The induction of vascular calcification by cytokine-enriched plasma is reduced after HCO and MCO dialysis.

Removal of bile acids by extracorporeal therapies: an in vitro study.

Bile acids (BAs) accumulating in the circulation in patients with liver failure are considered to be responsible for pruritus, which strongly impairs quality of life of the affected patients. The aim of this study was the in vitro characterization of different BAs regarding their removability with high-flux dialysis as well as with different adsorbents, and the evaluation of their binding to plasma proteins. Dialysis experiments were conducted in pediatric circuits with human plasma. For the adsorption studies, batch tests using 10% adsorbent in spiked human plasma were carried out. The binding of BAs to plasma compounds was determined by centrifugation of spiked plasma through spin columns. Sieving coefficients were determined using an albumin filter and a high-flux dialyzer. With high-flux dialysis, only hydrophilic BAs such as glycocholic and taurocholic acid could be removed efficiently, while all tested BAs were removed by adsorption. In conclusion, the hydrophilicity of BAs plays a major role in their removability using extracorporeal approaches. Adsorption-based systems offer particular advantages for the removal of hydrophobic BAs.

Measurement accuracy of total cell volume by automated dialyzer reprocessing: A prospective cohort study.

IntroductionDialyzer reprocessing machines have replaced human labor in preparing re-usable dialyzers. It also made the process of total cell volume (TCV) measurement become faster. Nevertheless, there has been a lack of data on efficacy of weight evaluation on TCV by machine compared to volume evaluation by the conventional method. The aim of this study was to evaluate the efficacy of TCV measurement performed by Kidney-Kleen® reprocessing machine, produced by MEDITOP Company in Thailand, compared to that of the conventional method.MethodsThis prospective cohort study was performed during September 2014 to December 2015.The low-flux (N = 101) and high-flux dialyzers (N = 100) were included for TCV evaluation. Reused times were up to 5 in the low-flux and 20 in the high-flux dialyzers. The Bland Altman analysis was used to evaluate value measured by different methods.ResultsThe values measured by weight evaluation (by machine) were higher than those obtained by volumetric evaluation of the conventional method in the low-flux (0.81 ± 0.20%) and high-flux (1.32 ± 0.39%) dialyzers. The correlation of TCV values of the two methods were r = 0.98, p < 0.001 and r = 0.71, p < 0.001 for the low- and high-flux dialyzers. Moreover, there was robust association and agreement between the two methods, confirmed by the Bland-Altman Analysis, which suggested that the values acquired by machine were within the limits of agreement, indicating acceptable accuracy of equipment.ConclusionThe approach of measurement differed from that of the conventional method (weight evaluation was used instead of volumetric evaluation), the reprocessing machine could offer accurate results.

High Cut-Off Hemodialysis for Myeloma Cast Nephropathy – Do We Finally Have An Answer?

The most common kidney presentation in patients with multiple myeloma (MM) is acute kidney injury (AKI) from cast nephropathy. Patients have a poorer 1 year survival compared to patients free of kidney involvement. The key to treating cast nephropathy is rapid reduction of free light chain (FLC) levels. The modern era of MM treatment was ushered in by the introduction of newer chemotherapeutic agents, such as bortezomib. Also, there is interest in the application of extracorporeal removal of FLCs with high cut-off hemodialysis (HCO-HD) using a dialysis membrane with a higher molecular weight cut-off pore size compared to conventional high-flux (HF) dialyzers. Does the use of HCO-HD provide additional benefit to bortezomib-based chemotherapy alone? Two trials have now been completed and the results were published in abstract form and orally presented at the 2016 American Society Nephrology Annual Scientific Meeting in Chicago, Illinois, USA. Both the MYRE and the EuLITE trials randomized patients with dialysis-dependent AKI due to biopsy-confirmed cast nephropathy to bortezomib-based chemotherapy, and either conventional high-flux hemodialysis (HF-HD) or HCO-HD with a primary end point of the discontinuation of renal replacement therapy. In the MYRE study, more patients in the HCO-HD arm were independent of dialysis at 6 months. In the EuLITE study, there was no difference in kidney recovery at 3 months. Both studies were small, which makes any firm conclusions on the benefit of HCO-HD tenuous. Based on the current knowledge, without more robust data, the routine use of HCO-HD cannot be recommended.

Effects of High Flux versus Low Flux on Serum C-Reactive Protein a as an Inflammatory Biomarker in Hemodialysis Patients

Background: Traditional low-flux dialysis cannot improve micro-inflammatory status, while new high-flux dialysis can improve the micro-inflammation and lipid metabolism, it helps to improve the quality of life and survival rate of patients, so how to improve the micro-inflammatory status are a focus for researchers. Objective: was to observe the effect of high flux hemodialysis (HFHD) with Gambro polyflux 170H dialyser and low flux hemodialysis (LFPD) with polyflux 17L dialyser on high-sensitivity C-reactive protein in patients with maintenance hemodialysis. Methods: 60 patients with maintenance hemodialysis were randomly divided into HFHD group and LFHD group. Another 20 cases for physical examinations served as normal control group. The maintenance hemodialysis patients were treated with HFHD using 170H dialyser dliahyser and LFHD using 17L dialyser, three times per week, 4 hours once. After 6 months of the treatment, high-sensitive C-reactive protein was determined in patients as well as normal controls before and after treatment. Results and Conclusion: in two groups, the levels of high-sensitive C-reactive protein before the treatment were higher than normal control (P <0.001). In HFHD group, serum high-sensitive C-reactive protein markedly decreased (P <0.01). In LFHD group, these indices remained unchanged after the dialysis for 6 months. HFHD with 170H polysulfone dialyser is effective in improving micro-inflammation in maintained hemodialysis patients.

Technical characterization of dialysis fluid flow and mass transfer rate in dialyzers with various filtration coefficients using dimensionless correlation equation.

The objective of the present study is to evaluate the effect of filtration coefficient and internal filtration on dialysis fluid flow and mass transfer coefficient in dialyzers using dimensionless mass transfer correlation equations. Aqueous solution of vitamin B12 clearances were obtained for REXEED-15L as a low flux dialyzer, and APS-15EA and APS-15UA as high flux dialyzers. All the other design specifications were identical for these dialyzers except for filtration coefficient. The overall mass transfer coefficient was calculated, moreover, the exponents of Reynolds number (Re) and film mass transfer coefficient of the dialysis-side fluid (k D) for each flow rate were derived from the Wilson plot and dimensionless correlation equation. The exponents of Re were 0.4 for the low flux dialyzer whereas 0.5 for the high flux dialyzers. Dialysis fluid of the low flux dialyzer was close to laminar flow because of its low filtration coefficient. On the other hand, dialysis fluid of the high flux dialyzers was assumed to be orthogonal flow. Higher filtration coefficient was associated with higher k D influenced by mass transfer rate through diffusion and internal filtration. Higher filtration coefficient of dialyzers and internal filtration affect orthogonal flow of dialysis fluid.

Medium Cut-Off (MCO) Membranes Reduce Inflammation in Chronic Dialysis Patients-A Randomized Controlled Clinical Trial.

BackgroundTo increase the removal of middle-sized uremic toxins a new membrane with enhanced permeability and selectivity, called Medium Cut-Off membrane (MCO-Ci) has been developed that at the same time ensures the retention of albumin. Because many middle-sized substances may contribute to micro-inflammation we hypothesized that the use of MCO-Ci influences the inflammatory state in hemodialysis patients.MethodsThe randomized crossover trial in 48 patients compared MCO-Ci dialysis to High-flux dialysis of 4 weeks duration each plus 8 weeks extension phase. Primary endpoint was the gene expression of TNF-α and IL-6 in peripheral blood mononuclear cells (PBMCs), secondary endpoints were plasma levels of specified inflammatory mediators and cytokines.ResultsAfter four weeks of MCO-Ci the expression of TNF-α mRNA (Relative quantification (RQ) from 0.92 ± 0.34 to 0.75 ± 0.31, -18.5%, p<0.001)-α and IL-6 mRNA (RQ from 0.78 ± 0.80 to 0.60 ± 0.43, -23.1%, p<0.01) was reduced to a significantly greater extent than with High-flux dialyzers (TNF mRNA-RQ: -14.3%; IL-6 mRNA-RQ: -3.5%). After retransformation of logarithmically transformed data, measurements after MCO were reduced to 82% of those after HF (95% CI 74%–91%). 4 weeks use of MCO-Ci resulted in long-lasting change in plasma levels of several cytokines and other substances with a significant decrease for sTNFR1, kappa and lambda free light chains, urea and an increase for Lp-PLA2 (PLA2G7) compared to High-flux. Albumin levels dropped significantly after 4 weeks of MCO dialysis but increased after additional 8 weeks of MCO dialysis. Twelve weeks treatment with MCO-Ci was well tolerated regarding the number of (S)AEs. In the extension period levels of CRP, TNF-α-mRNA and IL-6 mRNA remained stable in High-flux as well as in MCO-Ci.ConclusionsMCO-Ci dialyzers modulate inflammation in chronic HD patients to a greater extent compared to High-flux dialyzers. Transcription of pro-inflammatory cytokines in peripheral leukocytes is markedly reduced and removal of soluble mediators is enhanced with MCO dialysis. Serum albumin concentrations stabilize after an initial drop. These results encourage further trials with longer treatment periods and clinical endpoints.

Optimal Design of Dialyzers.

Several types of synthetic dialysis membranes, including polysulfone, polyethersulfone, and polyester polymer alloy membranes, have asymmetrical structures. Dialyzers with these membranes show higher water and solute transport performance because the actual membrane thickness, which is related to the water and solute transfer resistance, is quite small compared with that in membranes with a homogeneous structure. The performance of a dialyzer depends not only on membrane permeability to water and solutes, but also on flow conditions of the blood and dialysate, which are determined during dialyzer fabrication. Many types of high-flux dialyzers with high-performance membranes have a high internal filtration/backfiltration (IF/BF) flow rate. In the enhanced IF/BF dialyzer, membrane fouling occurs more readily than with the conventional dialyzer because of the high local transmembrane pressure needed to enhance the IF/BF flow rate. To select the optimal enhanced IF/BF dialyzer for individual patients, we need to balance the disadvantage of membrane fouling with the advantage of increased convective transport. Key Messages: The following principles should guide dialyzer development in the near term. (1) Dialyzers should show high performance for the removal of low-molecular-weight proteins related to certain complications under conditions of low albumin and amino acid loss. (2) Dialyzers with biocompatible membranes are required to prevent severe adverse reactions, even though the causal relationship between these reactions and some complications remains to be clarified.

Treatment of Myeloma Cast Nephropathy (MCN): A Randomized Trial Comparing Intensive Haemodialysis (HD) with High Cut-Off (HCO) or Standard High-Flux Dialyzer in Patients Receiving a Bortezomib-Based Regimen (the MYRE Study, by the Intergroupe Francophone du Myélome (IFM) and the French Society of Nephrology (SFNDT))

▪Multiple myeloma (MM) is often revealed by acute kidney injury (AKI) usually related to MCN. Recovery of renal function is a key prognostic factor. With novel anti-myeloma agents, HD-independence occurs in about 30% of pts with severe AKI, advocating for the use of additional strategies to rapidly remove circulating monoclonal free light chains (FLC).We designed a prospective randomized trial to compare the HD-independence rate in pts with inaugural severe AKI secondary to biopsy-proven MCN, treated by intensive HD (8 sessions over the first 10 days, then thrice a week) using either a HCO dialyzer or a conventional high-flux dialyzer. In both groups, pts received 21-day courses of Bortezomib and dexamethasone (BD), reinforced by cyclophosphamide after 3 cycles in the absence of haematological response (HR).Between 2011 and 2015, 98 pts were randomised. One pt withdrew consent, and 3 had main exclusion criteria. Baseline characteristics in the control arm (n=48) and HCO arm (n=46) were close, including similarly high serum FLC levels (median 6,015mg/L).HD independence was achieved in 33% and 43% (p= 0.31) at 3 and in 37.5% and 60 % (p=0.03) at 6 mo, in the control and HCO arms, respectively. HR rate of very good partial response or above at 3 mo based on FLC was 48% in control and 59% in HCO groups (p=0.29). Tolerance of HD schedule and of chemotherapy was acceptable in both arms. At 12 mo, 17 pts have died (10 vs 7).This randomized trial demonstrates that in MM patients with MCN and severe AKI treated with a bortezomib-based regimen, intensive HCO-HD results in higher renal recovery rate than HD with conventional high-flux dialyzers. DisclosuresAugeul-Meunier:janssen: Consultancy; gilead: Consultancy. Benboubker:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

A reliable method to assess the water permeability of a dialysis system: the global ultrafiltration coefficient.

Background: Recent randomized controlled trials suggest that sufficiently high convection post-dilutional haemodiafiltration (HC-HDF) improves survival in dialysis patients, consequently this technique is increasingly being adopted. However, when performing HC-HDF, rigorous control systems of the ultrafiltration setting are required. Assessing the global ultrafiltration coefficient of the dialysis system [GKD-UF; defined as ultrafiltration rate (QUF)/transmembrane pressure] or water permeability may be adapted to the present dialysis settings and be of value in clinics. Methods: GKD-UF was determined and its reproducibility, variability and influencing factors were specifically assessed in 15 stable patients routinely treated by high-flux haemodialysis or HC-HDF in a single unit. Results: GKD-UF invariably followed a parabolic function with increasing QUF in dialysis and both pre- and post-dilution HC-HDF (R2 constantly >0.96). The vertex of the parabola, GKD-UF-max and related QUF were very reproducible per patient (coefficient of variation 3.9 ± 0.6 and 3.3 ± 0.3%, respectively) and they greatly varied across patients (31–42 mL/h−1/mmHg and 82–100 mL/min, respectively). GKD-UF-max and its associated QUF decreased during dialysis treatment (P < 0.01). The GKD-UF-max decrease was related to weight loss (R2 = 0.66; P = 0.0015). Conclusions: GKD-UF is a reliable and accurate method to assess the water permeability of a system in vivo. It varies according to dialysis setting and patient-related factors. It is an objective parameter evaluating the forces driving convection and identifies any diversion of the system during the treatment procedure. It is applicable to low- or high-flux dialysis as well as pre- or post-dilution HDF. Thus, it may be used to describe the characteristics of a dialysis system, is suitable for clinical use and may be of help for personalized prescription.

Removal of uremic toxins by renal replacement therapies: a review of current progress and future perspectives

Accumulation of uremic toxins induces various uremia-related complications in patients with chronic kidney disease, particularly those undergoing dialysis treatment. Direct interactions of uremic toxins with organ tissues are thought to be a major pathophysiological mechanism for disease; for example, indoxyl sulfate reacts directly with macrophages and accelerates atherosclerosis. The removal of sufficient volume of uremic toxins will prevent uremia-related complications in dialysis patients. Hemodialysis with the use of a high-flux dialysis membrane, long or frequent treatment, and increased blood/dialysate flow has improved removal of water-soluble small molecular weight uremic toxins. Middle molecular weight molecules are removed more effectively with hemodialysis using a high-flux membrane, hemodiafiltration and hemofiltration, and a direct hemoperfusion method using β2-microglobulin adsorption column, which is useful in reducing serum β2-microglobulin levels as well as improving dialysis-related amyloidosis-induced clinical symptoms. With improvements in dialysis therapies, removal of low and middle molecular weight water-soluble molecules has improved; however, conventional dialysis treatment is limited in its ability to remove protein-bound uremic toxins (PBUTs). Recent findings suggest that adsorption treatments using oral charcoal adsorbent, mixed matrix membrane hollow fiber, and additive charcoal in the dialysate, in addition to conventional dialysis treatment, may effectively remove a substantial amount of PBUTs. Further improvement of renal replacement therapy, including dialysis and additional therapeutic strategies, is needed for better clearance of small and middle molecular weight molecules and PBUTs, which will lead to improved survival and quality of life for dialysis-dependent chronic kidney disease patients.

Performance of hemodialysis with novel medium cut-off dialyzers.

Background. Compared to high-flux dialysis membranes, novel medium cut-off (MCO) membranes show greater permeability for larger middle molecules. Methods. In two prospective, open-label, controlled, randomized, crossover pilot studies, 39 prevalent hemodialysis (HD) patients were studied in four dialysis treatments as follows: study 1, three MCO prototype dialyzers (AA, BB and CC with increasing permeability) and one high-flux dialyzer in HD; and study 2, two MCO prototype dialyzers (AA and BB) in HD and high-flux dialyzers in HD and hemodiafiltration (HDF). Primary outcome was lambda free light chain (λFLC) overall clearance. Secondary outcomes included overall clearances and pre-to-post-reduction ratios of middle and small molecules, and safety of MCO HD treatments. Results. MCO HD provided greater λFLC overall clearance [least square mean (standard error)] as follows: study 1: MCO AA 8.5 (0.54), MCO BB 11.3 (0.51), MCO CC 15.0 (0.53) versus high-flux HD 3.6 (0.51) mL/min; study 2: MCO AA 10.0 (0.58), MCO BB 12.5 (0.57) versus high-flux HD 4.4 (0.57) and HDF 6.2 (0.58) mL/min. Differences between MCO and high-flux dialyzers were consistently significant in mixed model analysis (each P < 0.001). Reduction ratios of λFLC were greater for MCO. Clearances of α1-microglobulin, complement factor D, kappa FLC (κFLC) and myoglobin were generally greater with MCO than with high-flux HD and similar to or greater than clearances with HDF. Albumin loss was moderate with MCO, but greater than with high-flux HD and HDF. Conclusions. MCO HD removes a wide range of middle molecules more effectively than high-flux HD and even exceeds the performance of high-volume HDF for large solutes, particularly λFLC.

Combining Inferior Vena Cava Diameter and Right Atrial Volume Index with Pro-BNP in Assessment of Volume Status in Haemodialysis Patients

1.1.Background: The need for a concept of dry weight derives from an awareness of the dangers of being fluid overloaded. Which reflected by strain on the heart also abnormal low fluid load is also harmful and it might be associated with unacceptable degrees of low blood pressure and consequently of ischemia of vital organs. To judge excess volume, there are no gold standards, but its assessment has been done using a variety of tools. Physical examination which based on patient’s interdialytic weight gain and clinical signs, the assessment of volume is made poorly by physical examination. The assessment of inferior vena cava (IVC) diameter and its collapse with inspiration have been the most commonly used echocardiographic techniques to assess intravascular volume. Right atrial volume index which is noninvasive echocardiographic tool for assessment of volume overload but not widely used due to lack of data about right atrial volume even in normal population. NT-pro BNP is one of natriuretic peptides which secreted mainly upon mechanical stretching of cardiomyocytes, Both BNP and NT-proBNP are eliminated during hemodialysis, but they show different behaviors depending on the chosen dialysis membrane. 1.2.Methods: The study was conducted on two groups group I include 20 ESRD patients maintained on regular HD three times/week, four hour/session which they subdivided into two subgroups. The 1st subgroup included ten patients using high flux dialyzers and the 2nd subgroup included ten patients using low flux dialyzers. Group II: include ten healthy subjects as a control group. We estimate Urea, Cr, Hg and NT pro BNP by enzyme linked immune-sorbent assay (ELISA), trans-thoracic echocardiography stressing on inferior vena cava diameter and collapsibility index, right atrial volume index to the patients before and after HD and also in 2nd group. 1.3.Results: There was statistical significant difference between the pre HD and post HD in mean BP, Rt. at volume index, IVC diameter, and IVC collapsibility index. There were statistical significant difference between the Pro BNP low flux in pre HD and post HD, the Pro BNP high flux in pre HD and post HD. 1.4.Conclusion: Mean BP, Rt. at volume index, IVC diameter and pro BNP high flux were significantly decreased post HD session, and IVC collapsibility index, and proBNP low flux were increased post HD. So we can combine these parameters for effected evaluation of dry weight.

Research on polyvinylidene fluoride (PVDF) hollow-fiber hemodialyzer.

In this study, polyvinylidene fluoride (PVDF) hollow-fiber hemodialysis membranes were prepared by non-solvent-induced phase separation. The PVDF hollow-fiber hemodialyzers were prepared by centrifugal casting. The results showed that the PVDF membrane had better mechanical and separation properties when the membrane wall thickness was 40 μm and the N,N-dimethylacetamide in the core was 70 Vol%. Compared with commercial polysulfone hemodialysis membrane (Fresenius F60S membrane), the PVDF membrane had better mechanical property and ultrafiltration (UF) flux of pure water. The PVDF dialyzer's removal efficiency for middle molecules was proven to be much higher than that of the F60S dialyzer. The UF coefficient of a high-flux PVDF dialyzer is 62.6 ml/h/mm Hg, whereas F60S is 42.5 ml/h/mm Hg, which can promote clearance for middle molecules.

Is Regional Citrate Anticoagulation the Future of Hemodialysis?

Citrate has many characteristics of the ideal anticoagulant for hemodialysis. In addition to immediate and complete anticoagulation in the dialysis circuit, citrate has important effects beyond anticoagulation, mainly in reducing inflammatory response induced by hemodialysis. Citrate has already become the standard anticoagulant in acute kidney injury requiring continuous renal replacement therapy (CRRT), both for adults and children, with the citrate module being a part of modern CRRT monitors. Although the citrate module is not yet available for intermittent hemodialysis, precise infusion pumps, point-of-care ionometers and high citrate clearance from high flux dialyzers increase safety while reducing the risk of metabolic complications, both in adult and pediatric patients. Slovenia has a long tradition, high volume and expansion of citrate use in hemodialysis, including long-term citrate anticoagulation in selected patients. At the Department of Nephrology, University Medical Centre Ljubljana, more than 10 000 citrate procedures were performed in 2015. We believe that regional citrate anticoagulation may replace heparin as the main anticoagulant for intermittent hemodialysis in the not so distant future.

Bioimpacts of dialyzer variety on phosphorus level in Iranian hemodialysis patients.

Introduction: Cardiovascular events are the major cause of death in patients with chronic renal failure. About half of dialysis patients because of reduced phosphorus clearance have hyperphosphatemia. Hyperphosphatemia and following secondary hyperparathyroidism lead to some cardiovascular changes. Hemodialysis (HD) partly removes phosphorus during each dialysis session. Objectives: Presented study was designed to evaluate dialyzer variation effect on phosphorus level as a prognostic factor after dialysis using. Materials and Methods: Six kinds of dialyzer were used for dialysis; low flux (LF) dialyzer (F7 and F8), high flux (HF) dialyzer (F70 and F80) and finally hollow-fiber dialyzers including polyethersulfone (PES) 130 HF and polysulfone (PS) 13 LF. Fifty-seven patients were divided into 6 matched groups included three groups of 10 people and 3 groups of 9 persons in groups: A (F70), B (F80), C (F7), D (F8), E (PES 130 HF) and F (PS 13 LF). Patients were treated for one month with these dialyzers. At the end of the month, blood samples were taken again for phosphorus level before dialysis handling. Results: The mean pre-dialysis serum phosphorus was 5.03, 5.4, 5.2, 4.6, 4.95 and 5.1 mg/dl and the mean phosphorus was 5.43, 5.01, 4.9, 4.18, 4.17 and 5.3 mg/dl after one month of dialysis, respectively in groups A to F without any statistically differences between pre- and after one month dialysis values respectively. Discussion: The findings indicate dialyzer type in the control of serum phosphorus has not been effective in the short-term HD. We suggest a study with more duration time.