Effect of sodium pool changes on blood pressure in patients undergoing PFD: design of a prospective randomized multicenter trial

Blood pressure control is important during dialysis and the interdialytic p eriod because of the frequency and potential seriousness of hypotension and hypertension. Water and sodium removal play an important role in the genes is of intradialytic cardiovascular instability or hypertension. Changing di alysate sodium concentrations without the aid of a kinetic model can someti mes give good results but is only an empirical approach. Therefore, this cl inical trial was designed to prospectively investigate the advantages of ch anges in the sodium pool on the blood pressure profile of patients undergoi ng paired filtration dialysis (PFD), The hypothesis to be tested is whether using a dialysate conductivity which, according to the conductivity kineti c model, ensures that the conductivity of the ultrafiltrate at the end of e ach dialysis session is 0.3 mS/cm more (B) or less (C) than the mean during the run-in period, improves blood pressure control either in patients pron e to intradialytic hypotension or patients who are hypertensive or normoten sive with antihypertensive treatment. Patients will be randomly allocated t o one of two treatment sequences (where treatment A is standard PFD): AABB or ABAA for patients with intradialytic hypotension; AACC or ACAA for hyper tensive patients. During the experimental phase arterial blood pressure wil l be measured and symptoms reported by the patients will be recorded.