The course of hematocrit value along the length of a dialyzer’s fiber: Hemoconcentration modeling and validation methods

Abstract

Objectives: Contemporary therapies for chronic kidney disease patients encompass a wide range of hemodialysis treatments, most of which rely greatly on dialyzers and hemofilters. The filtration process taking place in these devices with respect to the hemodynamic characteristics of the flow, has not yet been fully investigated. This study aims at improving the understanding of hemodynamics in a dialyzer by employing experimental methods and mathematical models. Methods: A semiempirical model has been formulated based on the principles of hemodynamics, considering the dominant phenomena of filtration-backfiltration and the corresponding driving forces. An in vitro hemodialysis circuit was accordingly assembled for experimental data acquisition, and subsequently for model validation. The circuit consisted of two dialyzers arranged in sequential order, in pursuance of increasing the number of sampling points. Fresh, heparinized porcine blood was used throughout the course of this study. Pressure and flow data obtained from in vitro investigations with the hemodialysis circuit were used as an input for the semiempirical model. Findings: The model predicted a substantial divergence in the course of hematocrit value along the length of the hollow fibers, which is corroborated by the experimental data. Particularly in certain operational conditions, hematocrit rose from 25% at the inlet to 65% halfway along the dialyzers’ length, to end at 30% at the outlet. Conclusion: Validation of the model’s predictions with experimental data demonstrated a very good agreement, confirming the model’s accuracy. Potential implementation of the model in clinical practice in the future might contribute greatly to an improved hemodialysis experience.

Quantification of dissolved H2 and continuous monitoring of hydrogen-rich water for haemodialysis applications: An experimental study

“…This may prove particularly enlightening since hydrogen's anti-oxidative and anti-inflammatory action might be appealing to a wide range of disciplines, especially when one takes into account blood trauma and the pro-inflammatory influence of commonly used medical devices such as pumps, filters and catheters, where cell distribution induced by diversified flow patterns is prevalent. [40][41][42]…”

The effect of ultrafiltration transmembrane permeation on the flow field in a surrogate system of an artificial kidney

“…In the 1990s, the progress from conventional hemodialysis (HD) controlled by diffusion and known as low-flux hemodialysis (LFHD) to new RRTs like hemofiltration(HF), hemodiafiltration (HDF) and high-flux HD (HFHD) (Cheung et al, 2003) was due to the introduction of ultrafiltration (UF) membranes characterized by high convective permeation fluxes. Despite the advancement on the efficient removal of small water-soluble toxins and slight improvement on the removal of middle size molecules and protein bound uremic toxins (Vanholder et al, 2003), fluid volume removal and hemodynamic management remains as a matter of concern due to its association to cardiovascular stress and potential organ damage (Canaud et al, 2019;Poorkhalil et al, 2019).…”

Intensification of Middle- and High-Molecular-Weight Toxins Removal in Dialysis Process

“…1,2 Hemodialysis is effective in removing and controlling the levels of small-molecular-weight substances such as urea and creatinine. [3][4][5][6] However, other toxins, such as middle-and highmolecular-weight toxins, are not efficiently removed with current hemodialysis techniques. 7 Studies have reported that the accumulation of these toxins may be associated with decreased life expectancy.…”