Achieving high convection volumes in postdilution online hemodiafiltration: a prospective multicenter study.

Background. Available evidence suggests a reduced mortality risk for patients treated with high-volume postdilution hemodiafiltration (HDF) when compared with hemodialysis (HD) patients. As the magnitude of the convection volume depends on treatment-related factors rather than patient-related characteristics, we prospectively investigated whether a high convection volume (defined as ≥22 L/session) is feasible in the majority of patients (>75%). Methods. A multicenter study was performed in adult prevalent dialysis patients. Nonparticipating eligible patients formed the control group. Using a stepwise protocol, treatment time (up to 4 hours), blood flow rate (up to 400 mL/min) and filtration fraction (up to 33%) were optimized as much as possible. The convection volume was determined at the end of this optimization phase and at 4 and 8 weeks thereafter. Results. Baseline characteristics were comparable in participants (n = 86) and controls (n = 58). At the end of the optimization and 8 weeks thereafter, 71/86 (83%) and 66/83 (80%) of the patients achieved high-volume HDF (mean 25.5 ± 3.6 and 26.0 ± 3.4 L/session, respectively). While treatment time remained unaltered, mean blood flow rate increased by 27% and filtration fraction increased by 23%. Patients with <22 L/session had a higher percentage of central venous catheters (CVCs), a shorter treatment time and lower blood flow rate when compared with patients with ≥22 L/session. Conclusions. High-volume HDF is feasible in a clear majority of dialysis patients. Since none of the patients agreed to increase treatment time, these findings indicate that high-volume HDF is feasible just by increasing blood flow rate and filtration fraction.

Optimization of the convection volume in online post-dilution haemodiafiltration: practical and technical issues.

In post-dilution online haemodiafiltration (ol-HDF), a relationship has been demonstrated between the magnitude of the convection volume and survival. However, to achieve high convection volumes (>22 L per session) detailed notion of its determining factors is highly desirable. This manuscript summarizes practical problems and pitfalls that were encountered during the quest for high convection volumes. Specifically, it addresses issues such as type of vascular access, needles, blood flow rate, recirculation, filtration fraction, anticoagulation and dialysers. Finally, five of the main HDF systems in Europe are briefly described as far as HDF prescription and optimization of the convection volume is concerned.

A Comparison of 8 Nutrition-Related Tests to Predict Mortality in Hemodialysis Patients.

OBJECTIVE: Protein-energy wasting (PEW) describes a state of decreased protein and energy fuels and is highly prevalent in hemodialysis patients. As PEW is associated with mortality, it should be detected accurately and easily. This study investigated which nutrition-related test predicts mortality and morbidity best in hemodialysis patients. DESIGN AND SUBJECTS: Data were used from CONTRAST, a cohort of end-stage kidney disease patients. Subjective Global Assessment (SGA), Malnutrition Inflammation Score (MIS), Geriatric Nutritional Risk Index (GNRI), composite score of Protein-Energy Nutritional Status (cPENS), serum albumin, serum creatinine, body mass index, and normalized protein nitrogen appearance rate were assessed at baseline. End points were all-cause mortality, cardiovascular events, and infection. Discriminative value of every test was assessed with Harrell's C statistic and calibration tested using the Hosmer-Lemeshow goodness-of-fit test. Ultimately, in every test, 4 groups were created to compare (1) hazard ratios (HR; worst vs best group), (2) HR increase per group, and (3) HR of worst group versus other groups. RESULTS: In total, 489 patients were analyzed. Median follow-up was 2.97 years (interquartile range, 1.67-4.47 years). MIS, GNRI, albumin, and creatinine discriminated all-cause mortality equally. SGA, cPENS, body mass index, and normalized protein nitrogen appearance were inferior. cPENS and creatinine were inadequately calibrated. Of the remaining tests, GNRI predicted mortality less when comparing HRs. MIS and albumin predicted mortality equally well. In a subanalysis, these also predicted infection equally well, but MIS predicted cardiovascular events better. CONCLUSION: Of the 8 investigated nutrition-related tests, MIS and albumin predict mortality best in hemodialysis patients. As one has no added value over the other, we conclude that mortality is most easily predicted in hemodialysis patients by serum albumin.

Treatment policy rather than patient characteristics determines convection volume in online post-dilution hemodiafiltration.

BACKGROUND/AIMS: Sub-analyses of three large trials showed that hemodiafiltration (HDF) patients who achieved the highest convection volumes had the lowest mortality risk. The aims of this study were (1) to identify determinants of convection volume and (2) to assess whether differences exist between patients achieving high and low volumes. METHODS: HDF patients from the CONvective TRAnsport STudy (CONTRAST) with a complete dataset at 6 months (314 out of a total of 358) were included in this post hoc analysis. Determinants of convection volume were identified by regression analysis. RESULTS: Treatment time, blood flow rate, dialysis vintage, serum albumin and hematocrit were independently related. Neither vascular access nor dialyzer characteristics showed any relation with convection volume. Except for some variation in body size, patient characteristics did not differ across tertiles of convection volume. CONCLUSION: Treatment time and blood flow rate are major determinants of convection volume. Hence, its magnitude depends on center policy rather than individualized patient prescription.

Plasmapheresis in myeloma cast nephropathy.

Renal failure in multiple myeloma is frequent, and portends a dismal prognosis. Precipitation of free light chains in tubules contributes to development of cast nephropathy and renal failure. Treatment with plasmapheresis is reported as an adjunct to chemotherapy in these patients, but evidence regarding its efficacy in the literature is conflicting. In this article, we report the case of a 63-year-old man who presented with severe acute renal failure due to myeloma cast nephropathy and whose kidney function improved significantly following treatment with dexamethasone and a course of 8 plasma exchanges. We then provide a review of the technical aspects of plasmapheresis, followed by an analysis of the randomized trials that have been published to date on the efficacy of plasmapheresis for myeloma cast nephropathy.

Gene polymorphisms as clinical tools in chronic glomerulopathies: a prospective study.

BACKGROUND/AIMS: Studies have proposed various polymorphisms of genes implicated in the physiopathology of chronic kidney disease as risk factors of progression and potential clinical tools. We sought to validate and simultaneously compare their predictive value in a prospective cohort of chronic glomerulopathies receiving recommended antihypertensive and antiproteinuric therapies. METHODS: Using PubMed, we identified 9 polymorphisms previously associated with progression. These were mostly of the renin-angiotensin-aldosterone and inflammation pathways: MCP-1 A2518G, TGF-ß1 T869C and C-509T, ACE I/D, AGT M235T, AT1R A1166C, TSC-22 A-396G, eNOS 4b/a and CYP11ß2 C-344T. We hypothesized that their determination would identify individuals at higher risk of progression. RESULTS: We recruited 93 predominantly male and Caucasian patients with a mean age of 63 and baseline eGFR of 33 ml/min/1.73 m(2) followed prospectively over a median of 36 months. 61% of patients had diabetic nephropathy, almost all received RAA blockade (90%) and none immunosuppressive therapy. The average blood pressure during follow-up was 140/72 mm Hg, the urinary protein to creatinine ratio 0.15 g/mmol and the rate of renal function decline -3.2 ± 4.1 ml/min/1.73 m(2)/year. Proteinuria and blood pressure strongly predicted progression. However, under recommended therapy, none of the proposed polymorphisms predicted renal function decline. In addition, none showed simple or partial correlations with the severity of proteinuria or blood pressure. Finally, summation variable of risk polymorphisms did not predict progression. CONCLUSION: This study does not validate the use of these 9 polymorphisms as individual clinical tools in patients with chronic glomerulopathies on recommended antihypertensive and antiproteinuric therapies.