Abstract: Dialysis fluid is the final product of a multi-step precision manufacturing process, with its quality directly impacting treatment efficacy and patient safety. Strict standards for dialysis water and ultrapure dialysis fluids have been established as essential prerequisites for online convective therapies, such as high-volume hemodiafiltration (HDF). These standards enhance the biocompatibility of the dialysis system, reduce systemic inflammation in dialysis patients, improve the response to erythropoiesis-stimulating agents, and ultimately have the potential to improve patient survival. This review provides a comprehensive update on the quality management requirements for water and dialysis fluids, with a specific focus on their role in optimizing high-volume hemodiafiltration.

Key words: Hemodiafiltration, Dialysis fluid, Water quality, Sustainability