Dialysate Sodium Lowering in Maintenance Hemodialysis

Abstract

Introduction: Lowering dialysate sodium may improve volume and blood pressure control in maintenance hemodialysis patients. Methods: We randomized 42 participants 2:1 to dialysate sodium 135 vs. 138 mEq/L for 6 months. This was followed by a 12 week extension in which sodium was increased to 140 mEq/L in low arm participants. The primary outcome was intradialytic hypotension (IDH). Secondary outcomes included dialysis disequilibrium symptoms, ER visits/hospitalizations, interdialytic weight gain, blood pressure (BP). Longitudinal changes across arms were analyzed using linear mixed regression. Results: Treatment to dialysate sodium 135 vs. 138 mEq/L was not associated with a difference in a change in the rate of IDH (mean change (95%CI) 2.8 (0.8,9.5) vs. 2.7 (1.1, 6.2) events per 100 treatments per month; ratio of slopes 0.96(0.26,3.61) or ER visits/hospitalizations (7.3 (2.3, 12.4) vs. 6.7 (2.9, 10.6) events per 100 patient months; difference 0.6(-6.9,5.8). Symptom score was unchanged in the 135 mEq/L arm (0.7 (-1.4,2.7) and decreased in the 138 mEq/l arm (5.0,8.5,2.0); difference 6.0 (2.1,9.8)). Interdialytic weight gain declined in the 135 mEq/L arm and was unchanged in the 138 mEq/L arm,(-0.3(-0.5,0.0) vs. 0.3 (0.0, 0.6) kg over 6 months; difference (-0.6 (-0.1,-1.0) kg). In the extension phase, raising dialysate sodium from 135 to 140 mEq/L was associated with an increase in interdialytic weight gain (0.2 (0.1, 0.3) kg), predialysis BP (7.0 (4.8, 9.2)/ 3.9 (2.6, 5.1) mm Hg) and a reduction in IDH [OR 0.66 (0.45, 0.97)]. Conclusion: Use of a dialysate sodium of 135 as compared with 138 mEq/L was associated with a small reduction in interdialytic weight gain without impact on IDH or predialysis BP, but with an increase in symptoms. Raising dialysate sodium from 135 to 140mEq/L was associated with a reduction in IDH, a small increase in interdialytic weight gain and a marked increase in predialysis BP.

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

“…The drawback is insufficient net Na removal, increased thirst, volume expansion, and hypertension [ 38 , 49 ]. Miskulin et al demonstrated that using a dialysate Na 135 mEq/L, as opposed to 138 mEq/L, resulted in a slight reduction in IDWG without impacting IDH or pre-dialysis blood pressure, albeit with an increase in symptoms [ 50 ]. Conversely, raising the dialysate Na to 140 mEq/L decreased episodes of IDH despite a slight increase in IDWG and pre-dialysis blood pressure [ 50 ].…”

Hemodialysis Procedures for Stable Incident and Prevalent Patients to Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

“…The drawback is an insufficient net Na removal, with increased thirst, volume expansion, and hypertension [35,46]. Miskulin et al demonstrated that using a dialysate Na 135 mEq/l, as opposed to 138 mEq/l, resulted in a slight reduction in IDWG without impacting IDH or pre-dialysis blood pressure, albeit with an increase in symptoms [47]. Conversely, raising the dialysate Na to 140 mEq/l decreased episodes of IDH despite a slight increase in IDWG and pre-dialysis blood pressure [47].…”

“…Miskulin et al demonstrated that using a dialysate Na 135 mEq/l, as opposed to 138 mEq/l, resulted in a slight reduction in IDWG without impacting IDH or pre-dialysis blood pressure, albeit with an increase in symptoms [47]. Conversely, raising the dialysate Na to 140 mEq/l decreased episodes of IDH despite a slight increase in IDWG and pre-dialysis blood pressure [47]. It is clear from the literature that there is no ideal dialysate Na.…”

Dialysate Sodium and Mortality

“…2 Furthermore, raising dialysate sodium from 135 to 140 mMol/L was associated with a 44% reduction in intradialytic hypotension occurrence but a small increase in interdialytic weight gain (0.2 [0.1-0.3] kg). 2 Accordingly, reducing dialysate sodium in patients without major fluid overload might only cause excessive risk of intradialytic cardiovascular stress because fluid status is already adequately controlled. 3 Conversely, raising dialysate sodium in patients in whom euvolemia is not difficult to achieve may just provide benefits on mortality through the reduction of intradialytic hypotension episodes and consequently end organ ischemia without too much concern for an inappropriate increase in weight gain.…”

“…Indeed, it has been recently shown in a randomized clinical trial that dialysate sodium 135 mMol/L was associated with a very small decrease in interdialytic weight gain (20.3 [20.5 to 0.0] kg) but with more dialysis disequilibrium symptoms, compared with dialysate sodium 138 mMol/L. 2 Furthermore, raising dialysate sodium from 135 to 140 mMol/L was associated with a 44% reduction in intradialytic hypotension occurrence but a small increase in interdialytic weight gain (0.2 [0.1-0.3] kg). 2 Accordingly, reducing dialysate sodium in patients without major fluid overload might only cause excessive risk of intradialytic cardiovascular stress because fluid status is already adequately controlled.…”