Membranes for endotoxin removal from dialysate: Considerations on feasibility of commercial ceramic membranes

As the quality of water in dialysis fluid varies considerably, dialysate is often contaminated by large amounts of bacteria and endotoxins. Membrane p roperties and operating pressures are acknowledged to give high-flux dialys is with bicarbonate the bacteriological potential to favor passage of endot oxin fragments from the dialysate into the blood stream. Therefore, a steri le dialysate will have to become a standard. Ultrafiltration across hydroph obic synthetic membranes was shown to remove endotoxins (and their fragment s) from dialysis water by the combined effect of filtration and adsorption. However, each module can be used for a limited time only. Ceramic membrane s may represent an alternative to polymeric membranes for endotoxin removal . In this article, we tested the capacity of different commercial ceramic m embranes with nominal molecular weight cut-off down to 1,000 to retain endo toxins from Ps. aeruginosa. The tested membranes did not generally produce dialysate meeting the Association for the Advancement of Medical Instrument ation standard. When using aluminum-containing membranes, we detected alumi num leaking into the dialysate that could possibly be transported into the blood stream.