Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study.

Background. Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH. Methods. Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH. Results. Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 +/- 3 versus 31 +/- 4% of sessions, respectively, P1=10.03), as was the per cent of clinical interventions (17 +/- 3% of sessions with almost one intervention on HFR-Aeq versus 22 +/- 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 +/- 3% of sessions with hypotension on HFR-Aeq versus 71 +/- 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq. Conclusions. HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na+ measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.