Performance of polysulfone membrane dialyzers and dialysate flow pattern

Area of Science:

• Nephrology
• Biomedical Engineering
• Medical Imaging

Background:

• Dialysate flow patterns are crucial for evaluating dialyzer function and optimizing design.
• Polysulfone membrane dialyzers (TS-UL and APS-S) were selected for investigation.
• Computed tomography (CT) with barium sulfate contrast was employed to visualize dialysate flow.

Purpose of the Study:

• To investigate and compare dialysate flow patterns in two polysulfone membrane dialyzers.
• To assess the clinical performance differences between the TS-UL and APS-S dialyzers.

Main Methods:

• In vitro: CT scans with barium sulfate contrast visualized dialysate flow in mock blood and dialysate.
• In vitro: Barium sulfate concentration was measured in defined regions of interest.
• In vivo: 12 hemodialysis patients switched from APS-S to TS-UL for 1 month to assess clinical parameter changes.

Main Results:

• CT scans revealed homogeneous dialysate distribution in TS-UL, but not in APS-S.
• Dialysate concentration curves were similar for TS-UL across regions, unlike APS-S.
• Significantly higher urea nitrogen clearance and albumin loss were observed with TS-UL compared to APS-S.

Conclusions:

• The TS-UL dialyzer exhibited superior clearance of substances across a wide molecular weight range compared to the APS-S.
• Differences in dialysate compartment design are likely responsible for the observed performance variations.