Despite the potential benefit, hemodiafiltration has not found widespread adoption. Reason for the reluctance in applying hemodiafiltration to a larger patient population are multiple and include lack of convincing cost-saving potential, safety concerns using a large volume of online-hemodiafiltration prepared substitution fluid. In addition, vascular access may be in adequate to match minimum blood flow requirements, staffs need to be specifically educated, and online-hemodiafiltration machines are more expensive.
The main reason may be a lack of convincing evidence of a survival benefit compared with standard conventional hemodialysis.
In the future, an international consensus definition of target ultrafiltration volume, as surrogate of convective dose, is needed to objectively assess the potential impact of convective therapies. Furthermore, in the absence of a general survival advantage with hemodiafiltration, target populations that benefit mostly from this treatment form need to be defined, and potential long term side effects of online-hemodiafiltration, such as chronic nutrient depeletion, need to be elucidated.