Membrane fouling and dialysate flow pattern in an internal filtration-enhancing dialyzer

Abstract

For efficient removal of large molecular weight solutes by dialysis, several types of internal filtration-enhancing dialyzers (IFEDs) are commercially available. However, in a pressure-driven membrane separation process (i.e., filtration), membrane fouling caused by adhesion of plasma proteins is a severe problem. The objective of the present study is to investigate the effects of internal filtration on membrane fouling based on the membrane's pure-water permeability, diffusive permeability, and sieving coefficient. Hemodialysis experiments were performed with two different dialyzers, IFEDs and non-IFEDs. Local membrane fouling in each dialyzer was evaluated by measuring the pure-water permeability, the diffusive permeability, and the sieving coefficient of native membranes and membranes treated with bovine blood. The effects of packing ratio on dialysate flow pattern were also evaluated by measuring the time required for an ion tracer to reach electrodes placed in the dialyzers. In the IFED, membrane fouling caused by protein adhesion is increased because of enhanced internal filtration only at the early stage of dialysis, and this fouling tends to occur only near the dialysate outlet port. However, enhanced internal filtration has little effect on measured membrane transfer parameters.

A peritoneal-based automated wearable artificial kidney

“…The extracorporeal circulation would require, given our current technology, continuous anticoagulation and a complex monitoring system, with the additional concern for known and yet unknown consequences of immunological and non-immunological bloodartificial surface interactions. Other possible complications would include membrane fouling [6] and exsanguinations, either through occult bleeding (in continuously anti-coagulated patients) or accidental disruption of the blood circuit. There is also the possibility that continuous extracorporeal circulation may negatively affect the longevity of the limited vascular access sites.…”

Composite Hybrid Membrane Materials for Artificial Organs

“…Because hemodialysis is performed in tubular membrane modules with hollow fiber membranes, there is a tendency to clog the membrane preferentially at the end of the module where the blood enters the membrane, which affects the process efficiency by decreasing the flow in time. To avoid this inconvenience, a larger number of hollow fibers with the small diameter can be used, which leads to uniform blood flow crossing the membrane [32].…”

Evaluation of asymmetrical structure dialysis membrane by tortuous capillary pore diffusion model

“…With APS-15E and FB-150U membranes, diffusive permeability for tryptophan, Vitamin B 2 , Vitamin B 12 (Wako Pure Chemical Industries, Ltd., Osaka, Japan) was measured by the optical fiber method we have proposed [8,[10][11][12]. Physical property of test solutes is summarized in Table 2.…”