Online Hemodiafiltration: treatment optimization and effects on biochemical parameters

Online hemodiafiltration is a promising dialysis technique with superior removal of uremic toxins as compared to conventional hemodialysis. Whether hemodiafiltration leads to improved clinical outcome is currently under investigation in the Dutch CONvective TRAnsport STudy (CONTRAST). In the first part of this thesis, the design and rationale of the CONTRAST study is described extensively. All data presented in this thesis originates from the CONTRAST study. State of the art treatment with online hemodiafiltration requires high convective volumes and sustained high microbiological quality of dialysis solutions. In the second part of this thesis, factors determining convective volumes in clinical practice were identified, to be able to establish highest possible volumes. In addition, the microbiological quality of dialysis solutions was evaluated in a sample of ten dialysis centers. In the third part of this thesis, the effects of hemodiafiltration on biochemical parameters (phosphate and beta-2-microglobulin) were evaluated. Residual kidney function appeared an important influencing factor of these parameters and was evaluated in more detail. In the last part of this thesis, practical recommendations to optimize convective volumes in clinical practice are provided. Furthermore, benefits and potential drawbacks of hemodiafiltration are summarized. Results from randomized controlled trials such as CONTRAST are warranted to provide conclusive evidence on the role of online hemodiafiltration to improve the prognosis of chronic hemodialysis patients.