Albumin Loss in Post-Dilution On-Line Hemodiafiltration Compared With Pre-Dilution On-Line Hemodiafiltration and Conventional Hemodialysis

Abstract

Background: The purpose of the study was to investigate the amounts of albumin lost in the dialysate in a dialysis session using either a high-flux (on-line hemodiafiltration (HDF)) or a low-flux filter (conventional hemodialysis (HD)).

Methods: The loss of albumin was studied in 10 hemodialyzed patients, with on-line HDF (pre- and post-dilution) and with conventional HD. We determined the albumin loss in the total ultrafiltrate for four different dialysis models.

Results: No change was found in serum albumin levels when switching from conventional HD to on-line HDF. The loss of albumin in on-line HDF post-dilution, with a high-flux filter of 2.5 m² (group A) was marginally significantly greater than the loss with the same filter with a surface area of 2.1 m² (group B) (P = 0.05). However, there was no difference in albumin loss when comparing groups A and B with group C (conventional HD) (P = NS). Albumin loss was significantly less in group D (pre-dilution on-line HDF, with filter 2.5 m² surface area) compared to groups A (P < 0.01), B (P < 0.01) and C (P < 0.03). The urea reduction ratio in each case (groups A, B, C and D) was, on average, > 73.5%, but in group C, it was significantly lower than in groups A and B (P < 0.05). Transmembrane pressure in group D was clearly lower than in groups A and B.

Conclusion: The polyethersulfone filters (polynephron) used in the on-line HDF lost very little albumin in a session (more with post-dilution), but this increased when their surface area and the transmembrane pressure increased. The urea reduction ratio was above the desired target in each model of dialysis using this filter, including both surface areas.

World J Nephrol Urol. 2023;12(1):1-7
doi: https://doi.org/10.14740/wjnu438