What Is the Optimal Sodium Concentration in the Dialysate?

Based on our experience in our hemodiafiltration unit we would recommend a personalized isonatremic dialysate bath. We currently prescribe 137 meq (isonatremic) or delta dialysate Na/serum Na less than 2 meq. In addition to the sodium prescribed in the dialysate, for the majority of our patients we do not restrict dietary sodium or water intake. The average sodium intake is 2775 mg per day and blood pressure is maintained without hypertensive medications. We acknowledge that part of the success for achieving dry weight may not be attributable only to the dialysate sodium but is likely the result of a combination of multiple factors such as convection therapy, cooling of dialysate, close monitoring of volume status during sessions with relative blood volume, presence of a nephrologist during all sessions and assessing volume status regularly with lung ultrasound and bioimpedance. In our experience, exercising during hemodialysis has additionally been associated with better hemodynamic status and less intradialytic hypotension. Moreover, we acknowledge there is little evidence to support a gradient dialysate to serum sodium of less than 2 meq and that our approach may not be optimal.