LAUSR

Abstract Introduction Online haemodiafiltration (OL-HDF) has been associated with increased survival. To date, the influence of the inner diameter of the hollow fibers of the dialyzer on convective volume has not been well established. The objective of the study was to evaluate the effect of increasing the inner diameter of the dialyzer on the convective volume and removal capacity. Material and methods We included 16 patients in postdilutional OL-HDF. Each patient was analyzed in 4 sessions in which the inner diameter varied; 185 μm (FX60 Cordiax and FX80 Cordiax) vs. 210 μm (FX600 Cordiax and FX800 Cordiax). Different solutes were measured at the beginning and end of each dialysis session. Results No differences in the convective volume were found with an increased inner diameter: 32.3 ± 3.1 vs. 31.8 ± 3.6 L/session (FX60 vs. FX600) and 33.7 ± 4.3 vs. 33.5 ± 3.8 L/session (FX80 vs. FX800). The reduction ratios also did not differ: urea 83.7 ± 4.5 vs. 84.1 ± 3.4 for FX60 and FX600, and 82.7 ± 4.1 vs. 83.6 ± 3.8 for FX80 vs. FX800; creatinine similar 78.2 ± 5.6 vs. 77.8 ± 4.6 and 77.1 ± 5.4 vs. 78.1 ± 4.9; β2-microglobulin 82.2 ± 4.3 vs. 82.9 ± 4.2, and 82.9 ± 4.7 vs. 84.0 ± 3.8; myoglobin 71.0 ± 10 vs. 70.2 ± 9 and 72.8 ± 11 vs. 75.0 ± 10; prolactin 70.4 ± 9 vs. 68.1 ± 9, and 72.2 ± 10 vs. 73.4 ± 8.2; and α1-microglobulin 22.9 ± 10 vs. 21.6 ± 10, and 26.5 ± 12 vs. 28.8 ± 11, respectively. Conclusion The increase in the inner diameter of the hollow fibers did not result in improved convective volume and removal capacity.