| [ Summary ] |
In order to remove middle to high molecular weight toxins efficiently, the pores of the membrance should be designed to be large enough to assure high permeability for macromolecules and water. Thus, the porosity and the average pore diameter of hemodiafiltration membranes should be made larger than those of conventional hemodialysis membranes. At the same time, the pore size distribution of the membrane should be tailored steep enough to keep the total amount of albumin leakage below four grams per session. It should be emphasized that pore size distribtion as well as mean pore size determins albumin permeability, and that membranes with broard pore size distribution are likely to cause massive albumin leakage, when a large amount of ultrafiltration volume is replaced. The selection of optimal pore characteristics is dependent on the filtration method and filtration volume in hemodiafiltration treatment. In the predilution method, by virtue of smaller albumin leakage, membranes with larger pores are usualy selected compared to the postdilution technique. |