Online hemodiafiltration (HDF) versus high-flux hemodialysis (hf-HD): A review

Chronic kidney disease affects a vast part of the world population and as a consequence gradually declines renal function. Patients enter the end stage of kidney disease as the disease progresses, and the use of renal replacement therapy such as hemodialysis then becomes necessary. With the advance of technology, new modalities of dialyzers have been made available in the market with the objective of making the hemodialysis process more efficient and of increasing its biocompatibility. This review aims to discuss different hemodialysis techniques, focusing on online hemodiafiltration and high-flux hemodialysis, in terms of molecular clearance, biocompatibility, cardiovascular stability, survival, safety, and costs. In comparison to conventional hemodialysis (low-flux), online hemodiafiltration and high-flux hemodialysis present a greater capacity to filtrate medium molecular weight molecules, presenting greater biocompatibility and maintaining cardiovascular stability during dialysis sessions, and constituting factors which can justify better outcomes of patients submitted to these modalities. However, studies differ on the real superiority of online hemodiafiltration when compared to high-flux hemodialysis, which highlights the need for further discussion on the subject.