Performance evaluation of developed polysulfone membrane hemodiafilters, ABH-F and ABH-P, in post- and pre-dilution hemodiafiltration

ABH-F and ABH-P have been developed for hemodiafiltration (HDF) therapy. In this study, we evaluated the solute removal characteristics of the hemodiafilters in a bovine blood in vitro study. The hemodiafilters were examined for 120 min at various filtration flow rates (Q F) (31.2–250 mL/min) under a constant blood flow rate of 250 mL/min and constant dialysate flow rates of 500/250 mL/min in pre-dilution HDF (pre-HDF) and post-dilution HDF (post-HDF). Creatinine clearance in pre-HDF was approximately 85 % of that in post-HDF because it was removed by molecular diffusion dominantly. The initial clearances of β2-microglobulin and α1-microglobulin increased with Q F and these values slightly and steeply decreased with time due to membrane fouling. Under a same Q F of 62.5 mL/min, higher clearance values in post-HDF were obtained compared with those in pre-HDF. All clearance values of ABH-P were higher than those of ABH-F under the same Q F. It seems that the ABH-P has a larger pore size of membrane than that in ABH-F. The creatinine and α1-microglobulin clearance values were obtained as highest at post-Q F62.5, the β2-microglobulin clearance values and transmembrane pressure were obtained as highest at pre-Q F250. Large solute clearances such as α1-microglobulin and albumin decreased with time in all HDF experiments. Time decay of large solute clearance values was observed in the HDF modality that had a higher clearance of the solute at 5 min later after the start of experiment.