Optimization of dialysate sodium in sodium profiling haemodialysis

Abstract

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.

Effect of Sodium Balance and the Combination of Ultrafiltration Profile during Sodium Profiling Hemodialysis on the Maintenance of the Quality of Dialysis and Sodium and Fluid Balances

“…Because it is neutral with respect to the intradialytic diffusive sodium balance (7,8,16), it is theoretically possible that it avoids the sodium gain-associated complications while preserving hemodynamic tolerance. Despite the Figure 3.…”

“…Nevertheless, the negative consequences by sodium gain have been frequently reported: Thirst, excessive interdialytic weight gain, dyspnea, and the development of hypertension (8 -15). Independent of the detailed course of a profile, an important consideration during sodium profiling HD is the sodium balance that is determined by the intradialytic diffusive sodium transport: Positive, negative, or neutral (7,8,16). We recently reported that the time-averaged mean of dialysate sodium has a close relationship with the complication related to intradialytic diffusive sodium gain (9).…”

“…When it is combined with sodium profiles, UF profile can potentate the elevation of plasma tonicity, providing a greater driving force for plasma refilling by high UF rate during a high-sodium period. It can also avoid hypovolemia, reducing the incidence of hypotensive episodes by low UF rate during a low-sodium period (4,7,8). Therefore, the combination of UF profile has been a common practice during sodium profiling HD (4,8,17).…”

Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids

“…Despite this, and thanks to some strategies based on current practice, with particular reference to calcium and magnesium concentration in the dialysate [16,20], dialysate temperature [21] and ultrafiltration and sodium concentration profiles [7,22-25], pressure stability is guaranteed as a general rule. Some electrolytes, particularly sodium and bicarbonate, can be modulated in profiles with the purpose of better respecting the gap in osmolarity or concentration that is established during the haemodialysis session, but their haemodynamic effect still remains controversial [21,23,25]. …”

Is there any role for sodium modeling in the prevention of intradialytic hypotension in patients with large interdialytic fluid gains?

“…Despite this measure, the majority of sodium profiles result in a positive sodium balance as evidenced by increases in IDWG, thirst, and blood pressure (16). The time‐averaged dialysate sodium concentration during dialysis plays a key role in determining net sodium flux and whether positive sodium balance occurs (17,18). Thus, positive sodium balance in sodium profiles can result in a vicious cycle of increased interdialytic thirst, larger ensuing IDWG, the need for additional UF with dialysis, and consequent risk for IDH.…”