Expanded hemodialysis as an alternative to suboptimal online hemodiafiltration

Introduction. Online hemodiafiltration (OLHDF) is associated to reduction in cardiovascular events and mortality when achieving high-dose convective volume. However, not all patients are able to reach the optimal volume of OLHDF or are not eligible for OLHDF. The aim of the present study is to compare expanded hemodialysis (HDx) and suboptimal post-dilution OLHDF in the reduction of solutes. Methods. In this observational prospective study we included all the patients of our hemodialysis units with suboptimal (i.e. convective volume <19.2 litres) OLHDF. After a minimum of one month in OLHDF, patients were switched to HDx for another month. Removal ratio (RR) for small, medium and large molecules were calculated for each period. In addition, we compared the global removal score (GRS) with both techniques. Results. Twelve patients were included (58% male, 68±16 years) and completed the study. OLHDF displayed higher RR of urea (p=0.011), prolactin (p<0.001), β2-microbloglulin (p=0.011), myoglobin (p=0.015), kappa free light chains (FLC) (p=0.04) and lambda FLC (p=0.012). In contrast, OLHDF and HDx presented similar RR of Creatinine, C-reactive protein, albumin, α2-macroglobulin, interleukin (IL)-1, IL-6, IL-8, IL-10, IL12, TNF-α, metalloproteinase-1 and p-cresol. The GRS was similar in OLHDF and HDx (55 [46-70]% vs 51 [41-59]%, NS). Conclusion. In conclusion, HDx presents a similar GRS in comparison to OLHDF demonstrating that this technique can be prescribed in cases of suboptimal convective volume achievement.