A simple efficient technique of 'mid-dilution' on-line hemodiafiltration.

On-line hemodiafiltration (OL-HDF) with pre- as well as post-dilution reinfusion mode provides superior uremic toxin removal, especially middle uremic toxins, and can improve patient survival. Both standard pre- and post-dilution have limitations. Mid-dilution OL-HDF (Nephros OLpur) was invented to overcome the disadvantages of both standard modes, but such a cartridge is only available in limited centers and is expensive. We created a simple technique of mid-dilution OL-HDF that can be easily set up in every hemodialysis center. Twelve stable end-stage renal disease patients were dialyzed in a random sequence with three different infusion modes of OL-HDF (simple mid-dilution, standard pre-dilution and post-dilution). Small molecule, middle molecule, and protein-bound uremic toxin clearances were measured. Simple mid-dilution OL-HDF provided high efficiency in uremic toxin clearances with less protein loss. Simple mid-dilution OL-HDF combines the advantages of pre- and post-dilution modes without adverse effects. Thus, this technique could be useful in decreasing morbidity and mortality in hemodialysis patients.