Short-Term Efficacy and Safety of Hemodialysis Using Super High-Flux Dialyzers Compared With Online Hemodiafiltration: An Exploratory Cross-Sectional Study in Vietnam

Background Online hemodiafiltration (OL-HDF) improves middle-molecule clearance but requires ultrapure water systems and specialized infrastructure, limiting implementation in many low- and middle-income countries. Super high-flux (SHF) dialyzers may enhance middle-molecule removal using standard hemodialysis platforms. This exploratory, single-session study evaluated the short-term biochemical efficacy and safety of SHF hemodialysis (SHF-HD) compared with post-dilution OL-HDF in a Vietnamese tertiary center. Methods In this cross-sectional pilot study, 30 maintenance hemodialysis patients (15 SHF-HD; 15 OL-HDF) were evaluated during a single 240-minute session. Pre- and post-dialysis concentrations of urea, β₂-microglobulin, parathyroid hormone, interleukin-6, leptin, albumin, and C-reactive protein (CRP) were measured. Reduction ratios were hematocrit-corrected. This study was not powered for non-inferiority or equivalence testing. Results Baseline characteristics were comparable, although blood flow rate (Qb) was higher in the OL-HDF group (270 ± 22 vs. 240 ± 24 mL/min; p = 0.008). No statistically significant differences were detected in reduction ratios of β₂-microglobulin (65.05% vs. 68.20%, p = 0.561), parathyroid hormone (66.32% vs. 63.57%, p = 0.803), interleukin-6 (23.62% vs. 21.20%, p = 0.213), or leptin (41.08% vs. 36.36%, p = 0.678). Serum albumin changes were minimal in both groups (-0.40 ± 0.68 vs. -0.44 ± 1.32 g/L, p = 0.911), and CRP remained stable. No intradialytic adverse events occurred. Conclusions In this exploratory Vietnamese pilot study, SHF-HD demonstrated similar short-term biochemical performance to OL-HDF during a single dialysis session, without acute safety concerns. Given the small sample size, non-randomized allocation, moderate convective volume, and absence of direct albumin quantification, these findings should be interpreted cautiously. Larger, prospective studies are required to determine long-term clinical implications.