Low-flux Dialysis Research Articles

A novel study on the quality of life index in canine chronic kidney disease treated with incremental intermittent hemodialysis.

In veterinary medicine, health-related quality-of-life index (QOLi) measurements are becoming increasingly important because they are a multifaceted concept that represents not only patients' physical well-being but also clients' emotional health. This study assessed QOLi in dogs receiving incremental intermittent hemodialysis (i-IHD) with high- and low-flux dialyzers. Thirty dogs diagnosed with chronic kidney disease (CKD) Stage IV were randomly divided into two groups of 15 dogs each. A high-flux dialyzer was used in Group I, whereas a low-flux dialyzer was used in Group II. i-IHD was performed on days 0, 2, 4, 19, and 34, whereas QOLi evaluation was performed on days 0, 15, 30, and 45. Both groups exhibited considerable decreases in post-dialysis creatinine, blood urea nitrogen, and phosphorus levels, while Group I experienced notable reductions in post-dialysis triglyceride and cholesterol levels. Dialysis adequacy did not show any significant difference between the clearance rates of high- and low-flux dialyzers. The QOLi assessment showed better post-dialysis scores in all categories except for water balance in Group I, while Group II demonstrated a worsening trend in scores for mental status, appetite, mobility, general health, and pain. In the first three sessions of i-IHD, dogs with CKD should be treated every other day, and the schedule can be extended by 15 days after that. A high-flux membrane, which effectively decreases triglyceride and cholesterol levels more than a low-flux membrane, warrants consideration for dogs with cardiovascular complications undergoing dialysis. The dialysis-related QOLi aids in clinical decision-making and encourages client engagement.

Hemodialysis patients have signs of a chronic thrombotic burden

BackgroundCardiovascular diseases are the dominant cause of morbidity in hemodialysis (HD) patients. Unless sufficient anticoagulation is used during HD, clotting may appear. The objective was to investigate if levels of fibrin degradation products (D-dimer) were increased before and during HD.MethodsThe combined observational study included 20 patients performing a total of 60 hemodialysis divided into three sessions of low-flux dialysis. None of the patients suffered from any clinically evident thromboembolic event before or during the study. Median bolus anticoagulation (mainly tinzaparin) doses were 84 Units/kg bow. Blood samples were drawn before HD (predialysis), and at 30min and 180min during HD with focus on analyzing D-dimer levels and its relation to interdialytic weight gain (IDWG) and speed of fluid elimination by HD (UF-rate).ResultsPredialysis, D-dimer levels (mean 0.767 ±0.821, min 0.136mg/L) were above the upper reference value in 95% of the sessions. D-dimer levels were lowered at 30min (p<0.001) and returned to predialysis levels at 180min. Predialysis D-dimer correlated with NT-pro-BNP, Troponin T, IDWG and UF-rate. Multiple regression analysis revealed that the D-dimer levels were significantly related to IDWG and the UF-rate.ConclusionsD-dimer levels were elevated in a high proportion predialysis and during HD and related to the IDWG and the UF-rate. Awareness of D-dimer levels and future studies will help clarify if optimization of those variables, besides anticoagulation and biocompatibility measures, will eradicate the repeated subclinical thromboembolic events related to each HD; one reason that may explain organ damage and shortened life span of these patients.

#360 Short-term treatment with medium cut-off dialyzers increases muscle mass with preserved fat tissue in maintenance HD patients

Abstract Background and Aims Protein-energy wasting is a significant complication of maintenance hemodialysis (HD) patients characterized by reduced fat or muscle mass and strength. The combination of non-modifiable general and disease-related factors, such as uremic toxin accumulation and systemic inflammation, is responsible for this condition. Medium cut-off (MCO) membranes are designed to provide clearance of large-middle molecular weight uremic toxins and inflammatory cytokines without causing loss of albumin. This study aimed to investigate the short-term effect of MCO dialyzers on fat tissues and muscle mass. Method We conducted a prospective, single-center cross-over study on maintenance HD patients treated with regular low-flux (LF) dialyzers. Fat tissues were measured with a skinfold caliper and mid-upper arm circumference. Muscle thickness and strength parameters from six different muscle groups were evaluated with ultrasound. The baseline (control) parameters were measured under LF dialyzers, and the measurements were repeated two weeks after switching to MCO dialyzers for the patients ordered by their clinicians according to the clinical indications. Results The median age was 69.5 (50.3,78.8) years, and 60% of the patients were female. Two weeks after switching to MCO, the Kt/Vs, urea reduction ratios, mean serum albumin, dry weight, and body mass index scores were similar. Mean skinfold thickness and mid-upper arm circumference were 15 mm (11,17) and 28mm (27,30) under LF and 16mm (14,19) and 28mm (27,30) under MCO dialyzers (p=0.82 and p=0.27). Rectus abdominis and external oblique muscle groups remained similar. Internal and external oblique muscle thickness were significantly increased (p=0.002 and p=0.001). Mean rectus femoris and gastrocnemius medialis (GKM) thicknesses were 1.19cm (0.99,1.33) and 1.16cm (0.9,1.4) under LF and 1.31cm (1.20, 1.40) and 1.24cm (0.95,1.40) under MCO dialyzers (p=0.002 and p=0.02). Mean GKM fibrile length and pennation angles were 2.4cm (2.2,2.8) and 20o (18,23) under LF and 2.7cm (2.4, 2.9) and 22o (19,24) under MCO dialyzers (p=0.007 and p=0.001). Conclusion Our study showed that MCO dialyzers increase muscle mass with preserved fat tissues in HD patients, short-term follow-up. This favorable effect might be due to the clearance of uremic toxins, which cannot be removed with conventional methods. If long-term studies support our findings, MCO dialyzers would be a milestone for the treatment of sarcopenia in HD patients.

#2032 Heart rate-adjusted augmentation index reduces after switching low-flux dialyzers to medium cut-off dialyzers in maintenance hemodialysis patients

Abstract Background and Aims Arterial stiffness affects almost all maintenance hemodialysis (MHD) patients and is one of the most important predictors of cardiovascular morbidity and mortality. Medium cut-off (MCO) membrane technology provides higher clearance of large-middle uraemic toxin and cytokines compared to conventional dialyzers. In this case-control study, we investigated the change in the arterial stiffness parameters after the transition to MCO dialyzers in MHD patients receiving treatment with low-flux dialyzers. Method We conducted a prospective, single-center cross-over study including 19 MHD patients receiving treatment with low-flux dialyzers. Baseline and repeated parameters were measured from the brachial artery on a mid-week HD session at 0th, 120th, and 240th minutes, and the average of the three measurements were analyzed. The repeated parameters were measured two weeks after the switching to MCO dialyzers which were decided by the clinician according to clinical indication. Results The median age was 71 (51, 79) years, and 57.9% of the patients were female. The frequency of diabetes was 36.8%, and hypertension was 73.7%. 21.1% patients were smokers. 31.6% of the patients had a history of cardiovascular disease. Two weeks after switching to MCO dialyzers, the Kt/Vs, urea reduction ratios, laboratory parameters, systolic, diastolic, and mean arterial pressures remained similar to baseline. The mean pulse wave velocity was 10.3 m/s (8.4, 11.0) with low-flux dialyzers and 10.2 m/s (7.0, 11.5) with MCO dialyzers (p = 0.38). The mean heart rate adjusted augmentation index [AIx(75)] was 20.0% (15.0, 30.3) with low-flux dialyzers and 13.0% (11.0, 22.0) with MCO dialyzers (p = 0.04). Conclusion Our study showed that the rapid effect of MCO membranes is the reduction in peripheral wave reflections defined by AIx(75). Additional long-term diseases are required to determine whether MCO dialyzers might improve the cardiovascular prognosis of MHD patients.

#91 Ultrafiltration rate induced cardiac strain (ULRICA) – study. Preliminary results of a prospective multicentre study in Sweden

Abstract Background and Aims Cardiovascular disease is the principal cause of mortality in the haemodialysis population, attributable not only to traditional risk factors but also to those specific to dialysis treatment such as fluid overload and ultrafiltration. These are modifiable risk factors. The cardiac biomarkers N-terminal pro-B-type natriuretic peptide (proBNP) and hs-Troponin T (TnT) increase during dialysis (Laveborn et al. 2012). Previous studies (Goto et al. 2023) hypothesize that this increase was related to ultrafiltration rate. The aim of the study was to determine if modifying ultrafiltration rate could reduce the elevation of these cardiac biomarkers. Method ULRICA is a multicentre study registered at ClinicalTrials.gov (NCT06153888), conducted in six centres across Sweden. It investigated the effect of ultrafiltration rate in adult, stable haemodialysis patients with a) interdialytic weight gain (IDWG) of more than 2.5% of dry body weight and b) an ultrafiltration rate of over 0.72 IDWG/h (standard UF rate). In a crossover setting each patient underwent one treatment according to standard prescription and, after one week, a second treatment with prolonged UF time to achieve an ultrafiltration rate of less than 0.6 IDWG/h or a reduction of ultrafiltration rate of at least 20% compared to standard treatment. All treatments were performed using low flux dialysers. Blood samples were collected before, after 180 min and after treatment. Levels of proBNP and TnT were then adjusted for haemoconcentration after the formula of Schneditz et al. (2012). Echocardiographic measurements were derived from echocardiographs performed within one year from study start under stable conditions. Due to the small sample size and non-normally distributed values, data were analysed using Wilcoxon signed-rank test for comparisons between treatments and Spearman's rank correlation coefficient for correlations. Results This preliminary one-centre report included 12 patients (four women, eight men) with a median age of 68.5 (range 32-86 years). There was a significant increase in TnT (p=0.008) and proBNP (p= 0.002) during dialysis with standard UF rate. The median levels of cardiac markers before treatment did not differ between the two treatments, TnT 61.5 ng/l (IQR 33.3-87.2) resp. 59.5 ng/l (IQR 35.5-90.0) and proBNP 12177.5 ng/l (IQR 3112.5-34773.0) resp. 9105 ng/l (IQR 2555.3-36803.0); (p=0.906 for TnT and p=0.638 for proBNP). The median increase of TnT was 4.1 ng/l (IQR 1.2-8.4) during standard treatment and 5.8 ng/l (IQR 0.1-10.3) during the prolonged treatment (p= 0.158). The median increase in proBNP was 3257.5 ng/l (IQR 855.0- 15074.7) during standard treatment and 2996.9 ng/l (IQR 724.1-13338.4) during the prolonged treatment (p=0.814). The changes at 180 min were also non-significant (p=0.182 for TnT and p=0.875 for proBNP). There was a positive correlation between the change in proBNP during treatment and age (R=0.85, p&amp;lt;0.001) and left ventricular mass index (LVMI) (R=0.89, p=0.019). There was also a correlation between age and LVMI (R=0.83, p=0.042). Conclusion Preliminary data of a small group of patients confirm an increase of TnT and proBNP during dialysis. Age and LVMI are strongly associated with increase of proBNP. To show whether a reduction of ultrafiltration rate per se might reduce the release of cardiac biomarkers during haemodialysis treatment, further inclusion of patients is in progress.

#730 Dialysis-induced changes in systolic, diastolic, and pulse pressure in maintenance hemodialysis patients

Abstract Background and Aims Hemodialysis (HD) therapy has a strong impact on cardiovascular function in both the short and long term. In the short term, the dialysis-induced changes in blood volume directly affect the arterial blood pressure (BP), frequently leading to intradialytic hypotension or hypertension, both associated with adverse outcomes. The aim of this study was to investigate the dialysis-induced changes in systolic (SBP), diastolic (DBP), and pulse pressure (PP) in maintenance HD patients and to assess their relationship with pre-HD BP. Methods 197 maintenance HD patients were studied during the middle dialysis session of the week. The mean pre-dialysis fluid overload was 2.0 ± 1.6 L (calculated as the difference between the pre-dialysis body weight and the target weight). All HD sessions lasted approximately 4 h and were performed using mainly low-flux dialyzers. SBP and DBP were measured pre-HD and post-HD using a sphygmomanometer. PP was calculated as SBP minus DBP. The patients were divided into two groups: A) patients with an intradialytic decline in SBP (∆SBP &amp;lt;0), and B) patients with an increase or no change in SBP during HD (∆SBP ≥0). Paired data were compared using the Student's t-test. Correlations between variables were assessed using Spearman's rho (ρ). Results During HD, SBP decreased in 120 (61%) patients (in 20 cases by more than 30 mmHg), remained unchanged in 11 (6%) patients, and increased in 66 (33%) patients (in 13 cases by more than 20 mmHg). DBP decreased in 94 (48%) patients, remained unchanged in 46 (23%) patients, and increased in 57 (29%) patients. In 76 (39%) patients both SBP and DBP decreased, whereas in 33 (17%) patients both SBP and DBP increased. In group A (n = 120), SBP, DBP, and PP decreased by 21 ± 16 mmHg (P &amp;lt; 0.001), 8 ± 11 mmHg (P &amp;lt; 0.001), and 13 ± 14 mm Hg (P &amp;lt; 0.001), respectively. In group B (n = 77), SBP, DBP, and PP increased by 12 ± 10 mmHg (P &amp;lt; 0.001), 4 ± 11 mmHg (P &amp;lt; 0.001), and 8 ± 13 mmHg (P &amp;lt; 0.001), respectively. Pre-HD SBP was 144 ± 23 mmHg in group A and 128 ± 25 mmHg in group B (P &amp;lt; 0.001). Pre-HD DBP was 80 ± 15 mmHg in group A and 68 ± 11 mmHg in group B (P &amp;lt; 0.001). In all patients combined, ∆SBP was similarly correlated with pre-HD SBP and pre-HD DBP (ρ = −0.42 in both cases, P &amp;lt; 0.001), whereas ∆DBP was more strongly correlated with pre-HD DBP (ρ = −0.52, P &amp;lt; 0.001) than with pre-HD SBP (ρ = −0.22, P &amp;lt; 0.01). ∆SBP was correlated with ∆DBP (ρ = 0.55, P &amp;lt; 0.001) and highly correlated with ∆PP (ρ = 0.78, P &amp;lt; 0.001). According to linear regression, SBP tended to increase during HD in patients with pre-HD SBP &amp;lt;118 mmHg (Fig. 1A), whereas DBP tended to increase in patients with pre-HD DBP &amp;lt;68 mmHg (Fig. 1B). Conclusions Patients with dialysis-induced decline in SBP (group A) had a significantly higher pre-HD BP (both SBP and DBP) compared with patients with an increasing or stable SBP (group B). This suggests that a high decline in SBP during HD appears to be more likely in patients with elevated pre-HD BP and that HD appears to have a pressure-normalizing effect in such patients. Similarly, a dialysis-induced increase in SBP or DBP appears to be more likely in patients with low values of pre-HD SBP or DBP, respectively.

Medium Cut-Off versus Low-Flux Dialyzers in Hemodialysis Patients with COVID-19: Clinical Outcomes and Reduction in Interleukin-6

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has caused extensive morbidity and mortality worldwide. Hemodialysis (HD) patients are both vulnerable to COVID-19 infection and tend to suffer greater disease severity and mortality. This retrospective study aimed to compare medium cut-off (MCO) and low-flux (LF) membrane dialyzers in terms of interleukin-6 (IL-6) reduction, change in inflammatory state, intradialytic complications, and mortality in chronic HD patients with COVID-19. Method: HD patients with a confirmed COVID-19 infection were admitted to the hospital for 10–14 days and underwent HD at the COVID-HD unit. Choice of dialyzer membrane used (MCO vs. LF) depended on the primary nephrologist(s). We collected data on demographics, baseline characteristics, laboratory results, diagnosis, treatments, HD prescription, hemodynamic status during HD, and mortality at 14 and 28 days after. Results: IL-6 reduction ratio (RR) in the MCO group was 9.7 (interquartile range, 71.1) percent, which was significantly higher than that of the LF group (RR, −45.7 [interquartile range, 70.2] percent). The incidence rate of intradialytic hypotension in the MCO group was 3.846 events per 100 dialysis hours (95% confidence interval [CI], 1.954–6.856), which was significantly lower than that of the LF group (9.057; 95% CI, 5.592–13.170). Overall, mortality was not significantly different between the two groups. Conclusion: The MCO membrane was more effective in removing IL-6 and was better tolerated than the LF membrane. Large, randomized controlled trials are required to confirm the relative benefits of the MCO membrane, especially mortality. However, due to the COVID-19 pandemic, our results suggest that the MCO membrane may be beneficial in chronic HD patients with COVID-19.

Clinical Outcomes in Patients on Hemodialysis with Congestive Heart Failure.

Congestive heart failure (CHF) is one of the common complications in patients with end-stage kidney disease. In the general population, CHF increases the risk of the death. However, there is no well-designed relevant study in the Chinese hemodialysis (HD) population addressing the risks associated with CHF. The aim of this study was to explore the impact of CHF on clinical outcomes in HD patients. Data from a prospective cohort study, the China Dialysis Outcomes and Practice Patterns Study (DOPPS) 5 (2012-2015), were analyzed. Demographic data, comorbidities, lab data, and death records were extracted. CHF was defined by the diagnosis records upon study inclusion. Our primary outcome was all-cause and cardiovascular (CV) mortality; secondary outcomes were all-cause and cause-specific hospitalization risk. Associations between CHF and outcomes were evaluated using Cox regression models. Stepwise multivariate logistic regression was used to identify the related risk factors, and subgroup analyses were carried out. Of 1,411 patients without missing CHF history information, 24.1% (340) had CHF diagnosis at enrollment. The overall mortality rates were 21.8% versus 12.0% (p < 0.001) in patients with and without CHF during follow-up, respectively. CHF was associated with higher all-cause mortality (adjusted HR: 1.72, 95% confidence interval [CI]: 1.17-2.53, p = 0.006), and the association with CV death was of similar magnitude (HR: 1.60, 95% CI: 0.91-2.81, p = 0.105). CHF patients had more episodes of hospitalization due to heart failure (HR: 2.93, 95% CI: 1.49-5.76, p < 0.01). However, compared with patients without CHF, the all-cause hospitalization risk was not much higher in CHF patients (HR: 1.09, 95% CI: 0.90-1.33, p = 0.39). Subgroup analysis found that the effect of CHF on all-cause mortality was stronger for male patients, patients with residual renal function, the elderly (≥60 years of age), patients with arteriovenous fistulae vascular accesses, nondiabetic patients, low-flux dialyzer users, and inadequately dialyzed patients (standardized Kt/V <2). In HD patients, CHF was found to be associated with a higher risk of all-cause mortality and cause-specific hospitalization risk. Further research is needed to identify opportunities to improve care for HD patients combined with CHF.

The use of a low-flux hemo-dialyzer is associated with impaired platelet aggregation in patients undergoing chronic hemodialysis.

In patients with chronic hemodialysis (HD), both abnormal thrombotic and bleeding events are commonly observed. Uremic platelet dysfunction is one of the important attributing factors. Moreover, HD may also result in aggregation dysfunction of platelets during the therapeutic procedure. However, how the HD process affects platelet and coagulation function is unknown and dialyzer membrane flux could have an impact on it. We aimed to compare the impacts of low-flux and high-flux HD on the platelet function of patients undergoing chronic HD. This was a cross-sectional study conducted in the HD unit of E-Da hospital in Taiwan. A total of 78 patients with maintenance HD three times per week for more than one year, including 40 with high- and 38 with low-flux hemodialysis, were recruited. Their platelet functions were evaluated using an in vitro platelet function analyzer (PFA-100) before and after the HD session. Of the 78 patients undergoing HD, 60 (76%) had prolonged pre-dialysis collagen/epinephrine (CEPI) and collagen/adenosine diphosphate closure times. Those receiving low-flux dialyzer had a significant increase in CEPI closure time (pre-dialysis 212.3 ± 62.1 seconds. post-dialysis 241.5 ± 64.3 seconds, P = .01), but not collagen/adenosine diphosphate closure time, after HD. After adjusting confounding factors, only the low-flux dialyzer demonstrated an independent association with the prolonged CEPI closure time after HD therapy (odds ratio = 23.31, 95% CI: 1.94-280.61, P = .01). We observed that impaired platelet aggregation is prevalent in patients undergoing chronic HD. Therefore, the use of low-flux dialyzers may further worsen platelet aggregation after dialysis. Patients with uremic bleeding diathesis should take precautions. We suggest that further studies using flow cytometry should be conducted to explore the mechanism of dialysis flux and platelet activity during HD.

Diffusive solute transport in hollow fiber dialyzers is not affected by variable feed viscosity

Dialyzer clearance (K) for hemodialysis is usually predicted from the mass transfer area product (K0A) provided in manufacturer data sheets without accounting for elevated feed-viscosity when treating blood. The boundary layer model for mass transport across hollow fiber membranes, however, predicts an increase in mass transfer resistance (1/K0) and a decrease in K with increasing feed-viscosity.The effect of increased feed-side viscosity relative to baseline crystalloid viscosity on small solute K and 1/K0 was therefore examined in commercial high- (HF) and low-flux (LF) dialyzers in lab-bench studies using standard dialysis equipment in the normal operating range. Homogeneous colloid solutions and bovine plasma were used to simulate the range of relative viscosities (ηrel) and oncotic pressures expected under in-vivo conditions. Internal filtration (IF) was quantified by a mathematical model to obtain diffusive transport characteristics (K’, 1/K0′).An up to 5-fold increase in ηrel caused a small increase in K and a small decrease in 1/K0 in HF, but not in LF dialyzers. After correction for a small convective contribution by IF, K’ and 1/K0′ remained constant in both LF and HF dialyzers.Diffusive transport characteristics of commercial HF and LF dialyzers are independent of variable feed-side viscosity. This suggests an insignificant contribution of the feed-side boundary layer resistance in dialyzers optimized for operation in hemodialysis. Increasing the feed-side viscosity, however, increases the convective component of dialyzer solute transport because of IF. Diffusive dialyzer clearance predicted from the dialyzer K0A is independent of elevated feed-viscosity.

Randomized Control Study on Hemoperfusion Combined with Hemodialysis versus Standard Hemodialysis: Effects on Middle-Molecular-Weight Toxins and Uremic Pruritus

Introduction: Classic hemodialysis schedules present inadequate middle-molecular-weight toxin clearance due to limitations of membrane-based separation processes. Accumulation of uremic retention solutes may result in specific symptoms (e.g., pruritus) and may affect clinical outcome and patient’s quality of life. Hemoperfusion (HP) is a blood purification modality based on adsorption that can overcome such limitations, and thus, it may be interesting to test the efficacy of at least one session per week of HP combined with hemodialysis. This is a randomized, open-label trial, controlled, multicenter clinical study to investigate the effect of long-term HP combined with hemodialysis on middle-molecular-weight toxins and uremic pruritus in maintenance hemodialysis (MHD) patients. Methods: 438 MHD patients from 37 HD centers in China with end-stage kidney disease (63.9% males, mean age 51 years) suffering from chronic intractable pruritus were enrolled in the study. Eligible patients were randomized into four groups: low-flux hemodialysis (LFHD), high-flux hemodialysis (HFHD), HP + LFHD, and HP + HFHD at a 1:1:1:1 ratio. Beta-2 microglobulin (β2M) and parathyroid hormone (PTH) were measured at baseline, 3–6, and 12 months. At the same time points, the pruritus score was evaluated. The primary outcome was the reduction of β2M and PTH, while the secondary outcome was the reduction of the pruritus score. Results: In the two groups HP + LFHD and HP + HFHD, there was a significant decrease of β2M and PTH levels after 12 months compared to the control groups. No significant differences were noted between HP + LFHD and HP + HFHD. Pruritus score reduction was 63% in the HP + LFHD group and 51% in the HP + HFHD group, respectively. Conclusion: The long-term HP + HD can reduce β2M and PTH levels and improve pruritus in MHD patients independently on the use of high- or low-flux dialyzers, showing that the results are linked to the effect of adsorption.

High Flux Versus Low Flux Dialysis: Impact on Intradialytic Hypertension and Adequacy of Dialysis

High Flux Versus Low Flux Dialysis: Impact on Intradialytic Hypertension and Adequacy of Dialysis

Effects of Low-Flux and High-Flux Dialysis Membranes on Erythropoietin Responsiveness in Hemodialysis Patients.

Background Chronic kidney disease (CKD) is often accompanied by anemia. High-flux membranes contribute to a reasonable removal of uremic toxins which cause anemia in CKD. Inadequate data have described the efficiency of high-flux dialysis in promoting erythropoietin responsiveness in CKD patients in the Middle East. This study was conducted to compare the efficiency of maintaining high-flux hemodialysis versus low-flux dialysis for ≥1 year in promoting erythropoietin responsiveness and to show the factors associated with erythropoietin hyporesponsiveness in Arab chronic hemodialysis patients. Methods It was a retrospective cohort study that involved 110 subjects who were categorized into group 1 (50 patients receiving low-flux dialysis) and group 2 (60 patients receiving high-flux dialysis). History taking, examination, and laboratory investigations were conducted for all patients every 3 months from January 2021 to January 2022. Results Group 2 had significantly higher weight and body mass index than group 1 but lower cholesterol and intact parathyroid hormone levels than group 1. Erythropoietin resistance index levels did not differ between the two groups upon repeated measures over a 1-year follow-up. Significant risk factors for erythropoietin hyporesponsiveness on multivariate analysis were lower weight (Odds ratio (OR): 0.966; 95% Confidence interval (CI): 0.94–0.992; p=0.011), longer hemodialysis vintage (OR: 1.172; 95% CI: 1.036–1.325; p=0.012), lower hemoglobin levels (OR: 0.531; 95% CI: 0.362–0.779; p=0.001), and higher neutrophil-to-lymphocyte ratio (OR: 2.436; 95% CI: 1.321–4.493; p=0.004). Conclusion High-flux dialysis was not superior to low-flux dialysis in improving erythropoietin responsiveness.

MO646: Effect of a High-Flux Dialyzer Applied to HFR Supra on the Removal of Large Uraemic Toxins in Haemodialysis Patients: Results from a Randomized Controlled Study

Abstract BACKGROUND AND AIMS HFR-Supra (haemodiafiltration with the regeneration of the ultrafiltrate) is a highly biocompatible dialysis technique characterized by an adsorptive resin cartridge with high protein-bound toxin adsorption capacity without removal of albumin, mimicking both glomerular and tubular functions. However, the low-flux dialyzer contained in the second diffusive stage of the HFR Supra system may hamper the removal of large uraemic toxins. This study assessed the large uraemic toxin removal ability of a new HFR system (HFR-H) which combines adsorption such as in HFR-Supra, with a high-efficiency high-flux haemodialysis membrane. METHOD In an open, randomized, cross-over, single-center, controlled study, 16 adult chronic haemodialysis patients were treated by haemodiafiltration with the regeneration of the ultrafiltrate with the HFR-Supra or the HFR-H system. All other dialysis parameters were kept constant in both study arms. All the treatments were delivered with Flexya dialysis monitor (Medtronic) in the middle-week session, lasting 4-h. The reduction rate (RR) of urea, creatinine, phosphate, β2-microglobulin, kappa (κFLC) and lambda (λFLC) free light chains and albumin, was intra-individually compared for the two dialysis types with linear mixed models. RESULTS The RRs for β2-microglobulin, κFLC and λFLC were significantly higher with the HFR-H system than those obtained with HFR-Supra (Figure). There were no significant differences in the RR for urea, creatinine, phosphate, interleukin-6 and albumin. CONCLUSION This study demonstrates that treating patients with an HFR-H instead of an HFR-Supra system significantly increases the elimination of middle and large molecules.

Comparative Study on Elution of Polyvinylpyrrolidone on Dialyzers Using Ultraviolet Analysis and Iodine Method.

It is known that poly(arylethersulfone)-based dialyzers can elute poly( N -vinyl-2-pyrrolidone) (PVP). With regard to chronic renal replacement therapy, this is a burden for the patient, because PVP is deposited in different organs and cannot be degraded or released from there; so elutable PVP has to be minimized. Usually, the iodine method is used for quantification of extractable PVP. To overcome the chain length dependency of this method, we used an ultraviolet method that is independent from the PVP chain lengths; so the absolute amount of eluted PVP can be quantified. The current study shows the amount of eluted PVP on differently sterilized low flux dialyzers (1.6 m 2 , similar storage time, n = 12)-PS160 (Allmed, Egypt), F7HPS (Fresenius Medical Care, Germany), F16 (Wego, China), and B-16P (Bain, China). Using the ultraviolet method, the irradiated filters show a sum total of approximately 9 mg more eluted PVP compared with the steam-sterilized ones, whereas the iodine method shows a value about three times lower between different types of sterilization. The boundary conditions during the radiation sterilization could lead to PVP degradation instead of cross-linking. The resulting shorter PVP chains can be more easily rinsed out and can falsely decrease the calculated eluted PVP amount by using the iodine complexation method.

Low serum prealbumin concentration predicts long-term mortality in maintenance hemodialysis patients with hepatitis B and/or C virus infections.

Background and AimA low serum prealbumin concentration is common in maintenance hemodialysis patients with hepatitis B and C and may be associated with mortality. In this study, we assessed Department of Nephrology and Hemodialysis predictive value of a low serum prealbumin concentration on mortality in HD patients using reused low‐flux dialyzers who were infected with hepatitis B and/or C virus.MethodsWe used serum prealbumin levels to predict the long‐term mortality of 326 hemodialysis patients. The patients were divided into two groups: group 1 (n = 140, with hepatitis B and/or C virus infections), and group 2 (n = 186, without hepatitis virus infections).ResultsDuring a 5‐year follow‐up, there were 75 deaths due to all‐cause mortality (23.0%). Mortality was significantly higher (P < 0.001) in patients with hepatitis B and/or C infection (44%) than in those without hepatitis infection (8%). Serum prealbumin was lower in the hepatitis infected group and mortality group than in non‐infected group and survival group. Multivariate Cox regression analysis showed that long duration of HD and lower serum prealbumin and albumin were related to mortality in patients undergoing maintenance HD. Receiver operating characteristic curves showed that serum prealbumin had a good prognostic value in predicting mortality in both groups with hepatitis B and/or C virus infection and without hepatitis infection (AUC = 0.792 [95% confidence interval: 0.714–0.87], P < 0.001; cut‐off value = 24.5 mg/dl, sensitivity = 62.3%, and specificity = 88.6%).ConclusionIn HD patients, serum prealbumin was a good prognostic biomarker of mortality in both groups of patients with hepatitis B and/or C virus infections and without hepatitis infections.

Incidence of intradialytic hypertension in hemodialysis patients in Beheira governorate and effect of high flux versus low flux dialysis on it

Abstract Background Intradialytic hypertension (IDH) is a common complication of hemodialysis (HD) that is under-recognized and its significance is underappreciated. No standard definition of IDH exists. As a unifying criteria for the diagnosis of IDH has not been proposed, the focus of this review will be on systolic blood pressure (SBP) rise = 10 mmHg at = 4 over six consecutive sessions. IDH is estimated at 5–15% of HD patients. IDH has been associated with poor clinical outcomes in HD patients including increased hospitalizations, higher ambulatory blood pressure (BP), cardiovascular morbidity, and mortality. Aim of the Work To detect the incidence of IDH in HD patients in Beheira governorate and to compare the effect of high flux versus low flux dialysis on it. Patients and Methods This study was conducted on 200 patients on maintenance HD from different HD units in Beheira governorate. The patients were divided into two groups: Group 1: 100 patients on HD with high flux dialyzers and Group 2: 100 patients on HD with low flux dialyzers. Results: Incidence of IDH in HD patients in Beheira governorate was 23.5% at the start, 21% after one month and 13% after three months duration. Results of our study demonstrated that there were no significant differences between both groups as regards effect of high-flux vs low-flux dialysis on IDH after one month and at the end of the study (P &amp;gt; 0.05), but there was a significant decrease in number of IDH patients after one month duration and after three months in both high-flux and low-flux dialysis patients. In our study, there was significant improvement in the form of reductions in all of pre-dialysis BUN, post-dialysis BUN, serum creatinine levels and serum IPTH levels at the end of the study in high flux group compared to low flux group. Finally, our results showed significant improvement in serum hemoglobin levels in high flux group by the end of the study in contrast to the low flux group. Conclusion No significant difference in the effect of high flux versus low flux dialysis on IDH, but there was significant improvement in all of pre-dialysis BUN, post-dialysis BUN, serum creatinine levels and serum IPTH levels by the end of the study in the high flux group compared to the low flux group.

Super high-flux membrane dialyzers improve mortality in patients on hemodialysis: a 3-year nationwide cohort study.

ABSTRACTIntroductionIn Japan, dialyzers are classified based on β2-microglobulin clearance. Type I dialyzers are classified as low-flux dialyzers (<10 mL/min clearance), type II and III as high-flux dialyzers (≥10 to <30 mL/min and ≥30 to <50 mL/min clearance, respectively), and type IV and V as super high-flux dialyzers (≥50 to <70 mL/min and ≥70 mL/min clearance, respectively). Super high-flux dialyzers are commonly used, but their superiority over low-flux dialyzers is controversial.MethodsIn this nationwide prospective cohort study, we analyzed Japanese Society for Dialysis Therapy Renal Data Registry data collected at the end of 2008 and 2011. We enrolled 242,467 patients on maintenance hemodialysis and divided them into five groups by dialyzer type. We assessed the associations of each dialyzer type with 3-year all-cause mortality using Cox proportional hazards models and performed propensity score matching analysis, adjusting for potential confounders.ResultsBy the end of 2011, 53,172 (21.9%) prevalent dialysis patients had died. Mortality significantly decreased according to dialyzer type. Hazard ratios (HRs) were significantly higher for type I, II and III compared with type IV (reference) after adjustment for basic factors and further adjustment for dialysis-related factors. HR was significantly higher for type I, but significantly lower for type V, after further adjustment for nutrition- and inflammation-related factors. These significant findings were also evident after propensity score matching.ConclusionsHemodialysis using super high-flux dialyzers might reduce mortality. Randomized controlled trials are warranted to clarify whether these type V dialyzers can improve prognosis.

Population pharmacokinetics-pharmacodynamics of fondaparinux in dialysis-dependent chronic kidney disease patients undergoing chronic renal replacement therapy.

Data on the anti-Xa efficacy of fondaparinux in dialysis-dependent chronic kidney disease (DD-CKD) patients are scarce. This study characterizes the pharmacokinetics (PK) and pharmacodynamics (PD) of fondaparinux in DD-CKD patients undergoing renal replacement therapy (RRT), to assess dosing strategies. A retrospective, observational study was conducted using data on anti-Xa activity (112 samples) from 12 (3 male and 9 female) DD-CKD patients (median (IQR) age 71years (63-88), weight 73kg (59-98.5)). Eleven patients underwent high-flux or low-flux hemodialysis (HD) and one patient underwent peritoneal dialysis. Three patients were also treated with therapeutic plasma exchange (TPE). A non-linear mixed effects analysis was performed using NONMEM 7.3.0. The lab-specific slope of the relationship between fondaparinux concentration and anti-Xa levels was 1.18IU/µg. In a one-compartment model, clearance (CL) and volume of distribution (Vd) were 0.05289 L/h and 5.55 L, respectively. High-flux HD was found to increase the CL of fondaparinux 2.26 times. TPE also considerably increased CL, but the fold-change could not be accurately estimated. Low-flux HD and peritoneal dialysis did not impact PK parameters. Model-based simulations showed that standard dosing (2.5mg three times weekly before HD) results in a median anti-Xa activity of 0.55IU/mL and 0.98IU/mL, pre- and post-low-flux HD, respectively. In patients undergoing high-flux HD, these values are approximately 27% lower. Additional caution is warranted with TPE, as this treatment can reduce anti-Xa activity even further.

Effect of High-Flux versus Low-Flux Dialysis on the Rate of Bacteremia in Hemodialysis Patients

Bacteremia in dialysis patients is a major risk factor of mortality. The aim of this study was to assess the effectiveness of dialysis with high-flux versus low-flux dialyzer regarding risk of bacteremia in dialysis patients. This was a retrospective cohort study that included dialysis patients who underwent dialysis therapy at old dialysis center where old low-flux dialyzers were used and the new dialysis center where high-flux dialyzers were used. The rate of positive culture was more in high-flux group (37.0%) compared to low-flux group (24.5%), although the difference was not statistically significant (P = 0.13). The vascular access was mostly permanent catheter in high-flux group compared to low-flux group (48.9% vs. 28.6%, respectively; P = 0.06), while arteriovenous (AV) fistula was more prominent in low-flux group compared to high-flux group (65.3% vs. 47.8%, respectively; P = 0.06). This was reflected in the type of bacteria, which was mostly from Gram-positive family (Staphylococcus). The results showed higher risk of bacteremia in high-flux group as compared to low-flux group; however, permanent catheters were more prominent in high-flux group.