Haemodiafiltration: Principles, technique, and advantages over conventional haemodialysis

Conventional haemodialysis (HD) is a widely used therapy for the replacement of renal function in children with end-stage kidney disease (ESKD). HD is based on diffusive transport of solutes across a semipermeable membrane and is effective in removing small uraemic retention solutes, such as urea, and correcting electrolyte and fluid imbalances. However, it is poorly suited to the removal of larger uraemic retention solutes, such as β-microglobulin, even when high-flux membranes are used. As the importance of larger uraemic toxins has become recognised, the need for alternative therapies that provide better removal of those solutes has become evident. This insight led to the development of convective therapies, haemofiltration, and combined convective and diffusive therapies, haemodiafiltration (HDF) in the 1970s. Today, HDF is used in treating both acute kidney injury (as continuous veno-venous HDF) and ESKD. In this chapter, we discuss the principles of HDF, the technique and practical aspects of performing HDF in children, relevant paediatric and adult studies, and the advantages of HDF over conventional HD.