Khajohn Tiranathanagul

By Khajohn Tiranathanagul and Somchai Eiam-Ong

The high mortality of hemodialysis (HD) patients is partly due to the limited capacity of diffusion-based HD to remove large uremic toxins. Hemodiafiltration (HDF) which combines convection with diffusion could enhance both large and protein-bound uremic toxin removal. Recently, there have been several randomized controlled trials demonstrating that high-efficiency post-dilution online HDF could improve survival. Indeed, high blood flow rate, which is the necessary requirement, could not be achieved in some patients. The alternative HDF techniques that could provide comparative efficacy would be considered. Pre-dilution online HDF could be performed without risk of hemoconcentration. Mid-dilution online HDF could be conducted via either simple way by using two dialyzers with the substitution fluid line in between or using special designed dialyzer. Mixed-dilution online HDF requires additional substitution pump for both pre- and post-dilution. There are interesting HDF techniques that could be performed with the conventional HD machine and these include HD with double high-flux, enhanced internal filtration, or super high-flux dialyzers. These modalities enhance the convective clearance in combination with internal backfiltration within the dialyzer in HD platform. All of these alternative high-efficiency HDF modalities are available and can potentially provide quite equivalent benefits with the high-efficiency post-dilution online HDF.

Part of the book: Aspects in Dialysis