Ronco C, Cruz DN (eds): Hemodialysis – From Basic Research to Clinical Trials. Contrib Nephrol. Basel, Karger, 2008, vol 161, pp 191–198 Online Hemodiafiltration: A Multipurpose Therapy for Improving Quality of Renal Replacement Therapy Bernard Canaud a,b , Leila Chenine a , Delphine Henriet a , Hélène Leray a a Lapeyronie Hospital – Nephrology, and b Renal Research and Training Institute, Montpellier, France Abstract By combining diffusive and enhanced convective clearances, hemodiafiltration (HDF) offers the most efficient and biocompatible renal replacement therapy modality at the pre- sent time. HDF increases solute mass transfer and enlarges the molecular weight spectrum of uremic toxins, and reduces the microinflammation profile of dialysis patients. Online (ol) production of substitution fluid by ‘cold sterilization’ of dialysis fluid gives access to virtu- ally an unlimited amount of sterile and non-pyrogenic solution. ol-HDF provides a multi- purpose platform that permits to develop and customize HDF options (HDF, post-, pre-, mixed-, mid-dilution) to patients’ needs. With these unique features, ol-HDF should be considered as a dialysis platform permitting to develop new options such as feedback-controlled vole- mia, automation of priming and restitution and daily treatment schedule. At the present time, ol-HDF offers major options to enhance dialysis efficacy and to improve global care of patients. Copyright © 2008 S. Karger AG, Basel Introduction By combining diffusive and enhanced convective clearances, hemodiafil- tration (HDF) offers the most efficient instantaneous solute clearances at the present time. HDF increases instantaneous solute mass transfer and enlarges the molecular weight spectrum of uremic toxins removed [1–4]. By improving the hemocompatibility of the dialysis system, HDF reduces the microinflamma- tion profile of dialysis patients [5, 6]. Online HDF (ol-HDF) is now an estab- lished treatment modality that tends to gain in popularity in chronic renal disease patients [7–9]. Downloaded by: Fresenius Medical Care 193.41.37.3 - 4/27/2015 1:19:51 PM