Who is the winner, pre-, post-, or mixed-dilution hemodiafiltration?

Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial and No Derivatives License (http:// creativecommons.org/licenses/by-nc-nd/4.0/) which permits unrestricted non-commercial use, distribution of the material without any modifications, and reproduction in any medium, provided the original works properly cited. Online hemodiafiltration (HDF) is the most technologically advanced renal replacement therapy, combining convective and diffusive solute removal. Online HDF removes a larger volume of small and middle molecule uremic toxins compared to conventional hemodialysis (HD). Recent clinical trials demonstrated that HDF improves patient survival when adequate convection volumes are achieved [1,2]. Online HDF is more complex than conventional HD. Various modes of online HDF, differing by the site of replacement fluid infusion, are in use. The replacement fluid can be infused into the tubing downstream of the dialyzer (postdilution), upstream of the dialyzer (predilution), both upstream and downstream (mixed dilution), or into the middle of the dialyzer blood pathway (mid-dilution). Each has its strengths and limitations (Table 1). Postdilution mode is the most common method of fluid substitution in online HDF. Postdilution HDF is the most effective method in terms of solute removal. However, it can increase the viscosity of the blood before fluid substituWho is the winner, pre-, post-, or mixed-dilution hemodiafiltration?