Assessment of dialyzer surface in online hemodiafiltration; Objective choice of dialyzer surface area

Abstract

Introduction: Online hemodiafiltration (OL-HDF) is currently the most effective technique. Several randomized studies and meta-analyses have observed a reduction in mortality as well as a direct association with convective volume. Currently, it has not been well established whether a larger dialyzer surface area could provide better results in terms of convective and depurative effectiveness. The aim of this study was to assess the effect of larger dialyzer surface areas on convective volume and filtration capacity. Material and methods: A total of 37 patients were studied, including 31 men and 6 women, who were in the OL-HDF program using a 5008 Cordiax monitor with auto-substitution. Each patient was analyzed in 3 sessions in which only the dialyzer surface area varied (1.0, 1.4 or 1.8 m2). The concentrations of urea (60 Da), creatinine (113 Da), β2-microglobulin (11800 Da), myoglobin (17200 Da) and α1-microglobulin (33000 Da) were determined in serum at the beginning and end of each session in order to calculate the percent reduction of these solutes. Results: The convective volume reached was 29.8 ± 3.0 with 1.0 m2, 32.7 ± 3.1 (an increase of 6%) with 1.4 m2, and 34.7 ± 3.3 L (an increase of 16%) with 1.8 m2 (p