Optimization of dialysate sodium in sodium profiling haemodialysis

Sodium profiling haemodialysis is a modified method of sodium gradient dialysis during which dialysate sodium follows a time-dependent profile. Sodium profiling haemodialysis has claimed to reduce intradialytic discomforts such as hypotension, muscle cramps, and disequilibrium syndrome. Having the low sodium period is an essential part of the sodium profiling haemodialysis to compensate for the sodium gain during the high sodium period. In spite of this, however, the incidence of interdialytic complications that results from the excessive sodium gain has been reported in previous literature. Making the prediction of optimal dialysate sodium concentration for isonatric dialysis is practically very difficult since too many variables influence the sodium gradient, including the initial plasma sodium and tonicity and/or dialysis dynamics that differ from patient to patient and from treatment to treatment. As for sodium profiling haemodialysis, complexities are added further since details of profile, such as type and form of profile, or initial, terminal, or time-distribution of dialysate sodium are varied considerably. We have recently reported that the intradialytic sodium balance and interdialytic weight gain are directly related to the time-averaged concentration of dialysate sodium (TACNa). The dialysate sodium can be optimized using this concept of TACNa for sodium profiling dialysis. TACNa should be approximately 0.5-0.8 mmol/L lower than patient's predialysis serum sodium concentrations to achieve a sodium balance neutral dialysis. In that study the optimal TACNa, seems to be between 137.8 and 143.5 mmol/L. Such an optimal value should be defined for the individual centres based on their profile protocols for clinical use. In the future, dialysate sodium should be optimized based on the exact prediction of the postdialysis plasma sodium levels.