Introduction: Dialyzers with special kind of membranes are currently available with pores that have expanded the lightening capacity of medium molecules, allowing the development of a therapy concept: “Expanded Hemodialysis”. It has also been shown that the flow of dialysate (Qd) has little value in the removal of molecules in conventional hemodialysis, so the objective of this study is to evaluate the effectiveness of dialysis taking into account the rate of reduction of medium molecules in patients weighing less than or equal to 70Kg comparing a dialysate flow of Qd400ml / min vs a Qd500ml / min in expanded hemodialysis with TheranovaMR filter. Methods and Results: Retrospective analytical observational cohort study. 23 patients met inclusion criteria, 11 (47%) with Qd 400ml / min and 12 (52.1%) with Qd 500ml / min. The reduction rate was not statistically significant, except in the kappa chains, which was 0.71 and 0.64 with Qd400ml / min and Qd500ml / min respectively with a P 0.043. In addition, water consumption was lower in the Qd group of 400ml / min with an average saving of 24 liters per patient and 13,824 liters in 12 weeks. Conclusion: Using a Qd of 400ml / min in expanded hemodialysis compared to Qd of 500ml / min did not influence the effectiveness of dialysis in terms of reduction rate, while obtaining substantial water savings. However, there are no previous studies of these characteristics, so it is considered a pilot study and a larger sample is required for further studies.
