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

AbstractIntroductionOnline haemodiafiltration (OL-HDF) is most effective technique; several randomised studies and meta-analyses have shown a reduction in mortality, with a directly related association with convective volume. At present, it is not properly established whether the increasing in dialyser surface area may suppose better outcomes in terms of convective and clearance efficacy. The purpose of the study was to assess the effect of increase in dialyser surface area on the convective volume and clearance capacity.Materials and methodsA total of 37 patients were included, 31 male and 6 female subjects who were participating in an OL-HDF programme with a 5008 Cordiax monitor with autosubstitution. Each patient was analysed in three sessions, and only the dialyser surface area (1.0, 1.4 or 1.8m2) varied. In each session, urea (60Da), creatinine (113Da), β2-microglobulin (11,800Da), myoglobin (17,200Da) and α1-microglobulin (33,000Da) serum concentration at baseline and at the end of each session were determined, so the reduction of thes solutes could be calculated.ResultsConvective volume achieved was 29.8±3.0 with 1.0m2, 32.7±3.1 (6% increase) with 1.4m2 and 34.7±3.3L (16% increase) with 1.8m2 (p