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

Abstract

Excessive sodium gain is a major hindrance of sodium profiling hemodialysis (HD) that offsets the benefit in reducing intradialytic hypotension-related discomforts (IHD). Patients who showed frequent IHD (>30% of the sessions; n = 11) were enrolled in a prospective study that consisted of two phases. In the phase 1 study, eight treatment modalities were evaluated: Conventional HD (control), sodium balance-positive step-down sodium profiling HD (PS), sodium balance-neutral step-down sodium profiling HD (NS), sodium balance-neutral alternating sodium profiling HD (NA) without ultrafiltration (UF) profile, and all those with UF profile (UF only, PS+U, NS+U, and NA+U). The incidences of "dialysis failure," defined as the occurrence of one or more of (1) session failure (discontinuation of session <75% of planned time), (2) UF failure (%UF achieved <70%), and (3) delivery failure (Kt/V <1.1), were 48.5, 21.2, 42.4, 39.4, 45.5, 18.2, 21.2, and 18.2% in control, PS, NS, NA, UF only, PS+U, NS+U, and NA+U, respectively. Four treatments, PS, PS+U, NS+U, and NA+U, reduced the incidence of dialysis failure significantly as compared with control (P < 0.05) and were evaluated in the phase 2 study, a randomized controlled 6-wk crossover study. Parameters were measured in the steady state after a 6-wk maintenance of each treatment. Diffusive sodium gain (DeltaNa) was significantly increased with sodium balance-positive profiles with or without UF profile, PS and PS+U (PS 1.9 +/- 1.1, PS+U 1.7 +/- 1.0 mEq/L; both P < 0.05 to control -0.1 +/- 0.2, NS+U 0.5 +/- 0.4, NA+U 0.4 +/- 0.2 mEq/L). They also increased the interdialytic weight gain (PS 3.8 +/- 0.6, PS+U 4.0 +/- 0.6 kg; both P < 0.05 to control 2.7 +/- 0.6, NS+U 3.3 +/- 0.6 kg; both P = NS to NA+U 3.5 +/- 0.6 kg). Predialysis weight and the required amount of UF also increased significantly with these sodium balance-positive profiles. Although the absolute amount of UF was larger with PS and PS+U, %UF achieved targeting dry weight was higher with sodium balance-neutral profiles with UF profiles, NS+U and NA+U (NS+U 92.7 +/- 3.8, NA+U 93.7 +/- 6.8%; both P < 0.05 to control 72.6 +/- 14.0, PS 88.3 +/- 6.6, PS+U 88.2 +/- 8.2%). Postdialysis weight was closest to dry weight with these treatments showing Delta (postdialysis weight - dry weight) of 0.3 +/- 0.1 and 0.3 +/- 0.2 kg in NS+U and NA+U (both P < 0.05 to control 1.0 +/- 0.6 kg; both P = NS to PS 0.5 +/- 0.3, PS+U 0.5 +/- 0.4 kg). Incidence of excessive weight gain and subjective discomforts during the interdialytic period increased significantly with PS. In conclusion, continuous use of sodium balance-positive sodium profiles resulted in an undesirable steady state with sodium and fluid expansion offsetting their hemodynamic benefit. Sodium balance-neutral sodium profiles in combination with UF profile were associated with less sodium and weight gains, better UF performance with postdialysis weight closest to dry weight, and fewer interdialytic problems with the equivalent hemodynamic benefit. Therefore, it is proposed that sodium balance-neutral sodium profiling HD with UF profile is a better choice, ensuring the dialysis of quality without sodium gain-related complications.