Search results for "Hemodialysi"
showing 10 items of 128 documents
A parametric CFD study of hollow fiber membrane modules for hemodialysis
2022
Hemodialysis is a membrane-based process in which solute transport from the patient’s blood to a rinsing solution (dialysate) occurs by diffusion and ultrafiltration. Devices used in hemodialysis are cylindrical modules filled with hollow-fiber membranes which allow the removal of toxic substances and metabolic wastes from the blood, but inhibit the passage of proteins and cells to the dialysate. A predictive porous-media model of hemodialysis was developed and validated against experimental data. Unlike previous literature models, it requires only basic membrane properties (hydraulic and diffusive permeabilities and reflection coefficients) instead of relying on empirically adjusted global…
A porous media CFD model for the simulation of hemodialysis in hollow fiber membrane modules
2022
A computational model was developed to predict the performance of hollow fiber membrane hemodialyzers. Blood and dialysate were modelled as fluids flowing through two interpenetrating porous media. Concerning hydrodynamics, experimental Darcy permeabilities measured for commercial hemodialyzers were used for both compartments. Concerning mass transfer, both diffusion and ultrafiltration were simulated. On the blood side theoretical Sherwood numbers for parallel flow in pipes were adopted. On the dialysate side Sherwood numbers were derived from CFD predictions for regular hexagonal fiber bundles. Solute concentrations on the two sides were alternatively computed in an iterative way and were…
Performance Comparison of Alternative Hollow-Fiber Modules for Hemodialysis by Means of a CFD-Based Model
2022
Commercial hemodialyzers are hollow-fiber cylindrical modules with dimensions and inlet–outlet configurations dictated mostly by practice. However, alternative configurations are possible, and one may ask how they would behave in terms of performance. In principle, it would be possible to depart from the standard counter-flow design, while still keeping high clearance values, thanks to the increase in the shell-side Sherwood number (Sh) due to the cross-flow. To elucidate these aspects, a previously developed computational model was used in which blood and dialysate are treated as flowing through two interpenetrating porous media. Measured Darcy permeabilities and mass transfer coefficients…
Circulating levels of molecular adhesion correlate with stage of renal disease and C-reactive protein in chronic kidney disease
2007
BACKGROUND: Patients with chronic renal failure (CRF) suffer from a series of complications linked to the atherosclerotic process in which the endothelial dysfunction mediated by the activation of some adhesion molecules plays an important role. This study aims to evaluate circulating levels of intercellular adhesion molecules-1 (ICAM-1) and vascular cell adhesion molecules-1 (VCAM-1) in patients with predialysis CRF, on maintenance hemodialysis (HD) and after kidney transplantation (KTx) and to correlate them with some inflammation and nutritional indexes. METHODS: Thirty two patients with predialysis CRF, 30 on maintenance HD, 36 after KTx and 28 subjects as a control group (C) were inclu…
Role and clinical importance of Helicobacter pylori infection in hemodialysis patients
2008
Dyspepsia is an extrarenal symptom frequently found in hemodialysed patients; it is due to chronic renal failure, and uremic gastritis is a specific associated condition in chronic renal failure (CRF). On the other hand, in the general population, Helicobacter pylori infection is an important dyspepsia-related risk factor; its close connections with gastro-duodenal pathology are already known, above all the peptic disease in a really exclusive way. By observation of a dyalitic group of patients, opportunely matched with a no CRF group, we evaluated CRF-associated uremia and Helicobacter pylori infection which could eventually interact causing symptoms and lesions. A statistical analysis of …
Upper gastrointestinal diseases correlated to helicobacter pylori infection: Comparison between uremic and non-uremic patients. Review of the literat…
2012
Helicobacter Pylori is the first cause of infection of the upper gastrointestinal tract in hemodyalisis patients. The hemodialytic treatment can lead to spontaneous eradication of this bacteria, but the frequency of pathological involving the upper gastrointestinal tract is still higher in these patients compared to hemodialysis patients negative for the infection and normal patients. In consideration of virulence and pathogenicity of helicobacter pylori infection, there is the strong recommendation for eradication therapy in uremic patients, that it has been demonstrated to reduce the incidence of benign and malignant of the upeer gastrointestinal tract.
P1055REMARKABLE REMOVALS OF BETA-2-MICROGLOBULIN AND PHOSPHATE WITH SHORT-DAILY HOME HEMODIALYSIS USING LOW DIALYSATE FLOW RATE
2020
Abstract Background and Aims Short-daily hemodialysis (HD) with low-dialysate volume is an appealing portable dialysis approach for home use. Although this type of HD has proved being effective for the volume control and the clearance of low molecular-weight uremic toxins, limited data are available on the impact on the removal rates of other uremic toxins like β2-microglobulin (β2M) or phosphate (P), whose clearance is limited by sequestration into compartments, poor diffusion, high time-dependency, or protein binding. We evaluated the impact of short-daily HD with slow dialysate flow rate on the removal of solutes of different molecular weights and distribution volumes. Method Single-sess…
FP749The effect of short daily home hemodialysis with low-flow, lactate-buffered dialysate on nutritional status and body composition
2019
Evaluation of diagnostic criteria for analgesic nephropathy in patients with end-stage renal failure: results of the ANNE study
1995
It was found that in Belgium, renal imaging techniques, demonstrating a decreased renal mass of both kidneys combined with either bumpy contours or papillary calcifications, were the only methods to reliably diagnose analgesic nephropathy (AN) in patients with end-stage renal failure. However, these criteria were selected in an area with a high prevalence of this disease (15.6% of the dialysis population at December 1990). To evaluate the criteria selected to diagnose AN in populations with lower or unknown prevalences of AN, the Analgesic Nephropathy Network of Europe (ANNE) was formed, consisting of 23 dialysis units from 14 European countries and Brazil. During 1991-1992, 598 new patient…