Comparison of Middle-Molecule Clearance between Convective Control Double High-Flux Hemodiafiltration and On-Line Hemodiafiltration

Abstract

Hemodiafiltration (HDF) is now a well-recognized treatment modality for end-stage renal disease (ESRD) patients. It provides superior characteristics over conventional hemodialysis in many respects. On-line HDF, however, which has been mainly used in clinical practice, requires a special machine. Interestingly, the recently innovated convective-control double high-flux hemodiafiltration (CC-DHF) machine can provide HDF treatment with an adjustable convection rate by using the conventional volume-controlled dialysate flow hemodialysis machine in a modified way. The present study was conducted to compare the efficacy of CC-DHF compared to on-line HDF in terms of middle and small solute clearances in 12 stable, chronic hemodialysis patients who underwent hemodialysis three times a week for at least 6 months. The results showed that the β₂-microglobulin (β₂M) removal represented by the β₂M clearance in CC-DHF was comparable to that in on-line HDF (112.4±17.0 vs. 119.4±15.5 ml/min respectively, NS). Also, the β₂M reduction ratio in the CC-DHF group did not differ from the on-line HDF group (85.5±4.2% vs. 86.1±6.7%, NS). With regard to small solute clearances, the values of single-pool Kt/V and phosphate clearance did not differ between CC-DHF and on-line HDF groups. In conclusion, CC-DHF provides removal of β₂M and small molecule uremic toxins that is comparable to on-line HDF. An on-line HDF machine may not be available in all hemodialysis centers, whereas CC-DHF can be easily set up, with proper precautions regarding the fluid quality. Therefore, CC-DHF can provide the benefits of convective therapy to patients in situations where use of an on-line HDF machine is limited.