Evaluation of the impact of a new synthetic vitamin E-bonded membrane on anemia and rHuEPO requirement in ESRD patients with central venous catheters: a pilot study.

In the last years, the number of hemodialysis (HD) patients with erythropoietin (rHuEPO) resistance is increasing. Probably, central venous catheters (CVCs) contribute to this resistance by inducing inflammation and oxidative stress. This study was aimed to compare vitamin E-bonded dialyzer (PSVE) versus polyethersulfone membrane. Sixteen subjects with CVCs were included in a prospective two-arm crossover 12-month study. The primary endpoints were the rHuEPO requirement and the erythropoiesis-stimulating agents (ESA) index, which was defined by the ratio between weekly EPO dosage (IU/kg/week) and Hb levels (g/dl). The mean dosages of rHuEPO to maintain hemoglobin between 10.5 and 12 g/dl were 135 ± 59 and 101 ± 57 IU/kg/week with polysulfone and PSVE, respectively (P = 0.14). The ESA indexes were 12.1 ± 5.2 and 8.7 ± 5.2 (P < 0.0001) with polysulfone and PSVE, respectively. A trend towards consensual changes in protein glycoxidation, antioxidant, and inflammatory markers was observed. In conclusion, the study suggests a role for PSVE in the reduction of ESA index in HD patients with CVCs.

Evaluation of hygiene and safety controls for on-line paired hemodiafiltration (PHF).

BACKGROUND: On-line hemodiafiltration is gaining popularity due to increasing evidence of clinical benefits however it also requires strict attention to hygiene and safety as notable quantities of liquid are reinfused into the patient. Although most centers are improving their attention to water quality, a frequent concern is the inadvertent or accidental contamination of water and whether the redundant safety controls are sufficient to protect the patient. In the present study, in order to simulate a worst-case safety condition, we tested in vitro the reliability of paired hemodiafiltration - (PHF), under low, moderate and high bacterial contamination of the water supply. Tests were performed using various bacterial concentrations (range 85-2000 cfu/mL) of Pseudomonas Aeruginosa. Samples were analyzed from different sites throughout the entire on-line hemodiafiltration circuit for bacteria endotoxin, fungus and ability to stimulate whole blood production of TNFalfa. RESULTS: In the in vitro contamination study, with the three bacterial concentrations tested at various points of the circuit, bacteria were below the level of detection and endotoxins were < 0.01 UE/mL. Addition of dialysate samples taken after the first stage of microfiltration, as well as after the first and second stage of ultrafiltration and incubated with whole blood were not associated with stimulated production of TNFalfa . CONCLUSIONS: PHF appeared to be a safe and feasible method for on-line hemodiafiltration even in the unforeseen presence of bacterial contamination of the feed water or water distribution system.

[Safety controls in a new hemodiafiltration on line technique (PHF)]. / Controlli di sicurezza in una nuova tecnica di emodiafiltrazione on-line (PHF).

PURPOSE: On-line hemodiafiltration (HDF) is gaining popularity due to increasing evidence of clinical benefits. The purpose of this study was to test a new on-line technique paired hemodiafiltration (PHF). In addition, we evaluated the PHF system during in vitro contamination. METHODS: Five patients used the PHF technique over a 6-month period. We performed a disinfection protocol and tested for bacteria, endotoxin, halogenated carbons and metals in the feed water, and we tested for bacteria, endotoxins and fungi in the dialysate after different ultrafiltration stages. In vitro tests were performed using three bacterial concentrations of pseudomonas aeruginosa. Samples were analyzed from different sites throughout the entire on-line HDF circuit for bacteria endotoxins, fungus and the ability to stimulate whole blood production of tumor necrosis factor-alpha (TNF-alpha). RESULTS: The bacteriological control from the feeding machine water and at the entrance to the monitors had a bacterial level of <100 CFU/mL. No bacteria were detected in the dialysate and endotoxin levels were <0.03 EU/mL. In the in vitro contamination study, with the three bacterial concentrations tested at various points in the circuit, bacterial and fungi were below the level of detection and endotoxins were <0.03 UE/mL. The addition of dialysate samples taken after the 1st microfiltration stage, as well as after the 1st and 2nd ultrafiltration stage and incubated with whole blood were not associated with stimulated TNF-alpha production. CONCLUSIONS: PHF appeared to be a safe and feasible method for on-line HDF even in the unforeseen presence of the bacterial contamination of the feed water or in the water distribution system.

[New dialysis therapy modalities: what role do they play in the hemodialysis patient's outcome?]. / Nuovi schemi di terapia dialitica: quale ruolo nell'"outcome" del paziente in emodialisi?

Many studies have been devoted to investigating new techniques and new dialysis strategies aimed at achieving adequate removal of "uremic toxins". Conversely, few studies focus on the effect of different dialysis techniques on long-term outcome, including large series and with adequate follow-up. Dialysis dose, membrane biocompatibility and permeability, convective techniques, and the number and duration of dialysis sessions have all been considered as potentially related to patient outcome. The available data from the literature clearly show a significant relationship between the urea kinetic model based dialysis delivered and long-term patient outcome. A significant positive correlation between survival and Kt/V up to 1.3 per session in patients treated three times a week with standard low flux cellulosic dialyzers has been shown. Many studies have shown an effect of high flux membranes on the appearance of symptoms related to dialysis amyloidosis. It is likely that such an effect is further enhanced by convective or mixed techniques. The role of these techniques in patient survival is suggested by some studies, but should be confirmed in larger series. The use of techniques suitable for ultra-pure dialysis fluids are mandatory whenever high permeability membranes are used. Treatment schedules which include long dialysis sessions or an increased number of sessions such as daily dialysis, seem to be beneficial for the control of hypertension or hyperphosphatemia. However, their role on patient survival has not yet been clearly assessed. Together with the choice of the best strategy, great attention should be paid to other factors known to be related to patient outcome, such as early patient referral, and the type and efficiency of vascular access.