Comparative Analysis of Hemodiafiltration Methods: Efficacy and Safety in Maintenance Hemodialysis

BACKGROUND The removal of uremic toxins in patients with end-stage renal disease is most effectively achieved through hemodiafiltration (HDF). Mixed-dilution HDF (mix-HDF) is a novel technique that automatically adjusts the infusion ratio between pre-dilution HDF (pre-HDF) and post-dilution HDF (post-HDF) based on transmembrane pressure feedback, maximizing filtration without compromising ultrafiltration. This prospective single-center study aimed to evaluate and compare the efficacy and safety of mix-HDF with pre-HDF and post-HDF in patients on stable chronic hemodialysis. MATERIAL AND METHODS Twenty-seven adult patients undergoing maintenance dialysis were treated sequentially with pre-HDF (T1), post-HDF (T2), and mix-HDF with varying dilution ratios: T3 (20: 10), T4 (15: 10), and T5 (15: 15). Key outcomes included urea reduction ratio, reduction ratios of ß2-microglobulin and alpha1-microglobulin, and total dialysate removal amounts. Secondary endpoints were blood flow, transmembrane pressure, convective volume, and convective volume completion rate. Statistical significance was determined using the Kruskal-Wallis and Wilcoxon tests (P<0.05). RESULTS Urea reduction ratio did not differ significantly among the groups (P>0.05). ß2-Microglobulin reduction ratio was significantly lower in pre-HDF vs post-HDF and mix-HDF (P<0.05), while a1-microglobulin reduction ratio remained lower overall. T5 (15: 15) mix-HDF achieved alpha1-microglobulin clearance closest to post-HDF. Transmembrane pressure was highest in T5, followed by T2. Convective volume completion rate was highest in pre-HDF and mix-HDF (20: 10). CONCLUSIONS Mix-HDF demonstrated similar performance to post-HDF for small and middle molecule clearance and offered improved control over transmembrane pressure. It presents a safe and effective alternative to conventional HDF modalities and warrants further clinical validation.