Enhancement of convective transport by internal filtration in a modified experimental hemodialyzer

Abstract

This approach suggests that changes in design of the dialyzer may affect its performance. The use of internal filtration is suggested to improve convection and dialyzer efficiency for larger solutes without the requirement for high volumes of replacement fluid, as is the case for current hemodiafiltration techniques.

High-Flux Dialysis: Clinical, Biochemical, and Proteomic Comparison with Low-Flux Dialysis and On-Line Hemodiafiltration

“…They also indicate that due to its excellent clinical tolerability and safety, high-flux HD with cellulose triacetate membrane can be safely performed in aged patients The efficiency of high-flux HD, in particular with cellulose triacetate, resulted similar to on-line HDF, probably due to the “internal” hemodiafiltration, which happens during high-flux HD driving a convective transport along the hollow fibers similar to on-line HDF [15]. Furthermore, cellulose triacetate showed a high performance in myoglobin extraction, which could be useful in patients affected by rhabdomyolysis.…”

Solute Transport in Hemodialysis: Advances and Limitations of Current Membrane Technology

“…Under normal operating conditions of high-flux HD, fluid flow within the filter is characterized by (forward) filtration (blood to dialysate directionality) in the proximal part of the filter and "backfiltration" (dialysate to blood directionality) in the distal portion of the filter. The convective clearance provided by this internal filtration mechanism contributes substantially to the total clearance of larger MW substances in high-flux HD [28] .…”

Pulse Push/Pull Hemodialysis: Convective Renal Replacement Therapy

“…Changes in non-permeable molecular concentrations occur in response to the water content of blood, and thus, the kinetics of water transport across membrane can be evaluated by measuring the cumulative concentration changes of non-permeable molecules (Ronco et al, 1992). Radiolabeled albumin (a non-permeable molecule) has been employed to determine the amounts of convection for hemodialyzers with reduced fiber diameters or an obstacle in dialysate stream (Ronco et al, , 1998. A series of in vitro experiments proved that this scintigraphic method was accurate for measuring internal filtration rates, but despite its precision, its clinical application is not plausible due to the safety issue raised by the use of radio-labeled molecules and the complexities of the procedures and equipment.…”