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Abstract: SA-PO359

The Unresolved Quest: The Higher the Dialysate Sodium, the Better?

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Pinter, Jule, Universitatsklinikum Wurzburg, Wurzburg, Bayern, Germany

Group or Team Name

  • Hemodialysis registry working group from European Clinical Database 5

Half of all people receiving maintenance dialysis die within 5-years of treatment. Mortality is largely driven by cardiovascular disease. A key contributor to cardiovascular disease in dialysis recipients is persistent fluid and sodium overload. During dialysis, sodium removal occurs largely via convective (ultrafiltration, weight loss) but also through diffusive losses (dialysate-plasma sodium gradient), the latter being largely dependent on the difference between serum and dialysate sodium concentration. Whether a higher or lower dialysate sodium influences survival is unknown, recognizing that other factors (i.e.; volume status, hemodynamic conditions) may influence the outcome.


We conducted an observational time-to-event analysis in a large international database of incident hemodialysis patients to assess the relation between dialysate sodium and all-cause mortality. We utilized the European Clinical Database 5 from Fresenius Medical Care, which is a real-time electronic health record repository for hemodialysis patient care management. From 72,163 incident hemodialysis patients in 25 countries dialysate sodium measurements were retrieved over a period of ten years. The cox regression model for time to death assessed dialysate sodium concentrations and serum sodium concentrations (< 137 mmol/l, 137-139.9 mmol/l, >=140 mmol/l). Age, sex, ethnicity, body mass index, comorbid conditions, laboratory values, treatment variables and mediators were adjusted for before the final model accounted for fluid overload, ultrafiltration, antihypertensive medication, diuretics and overweight.


A dialysate sodium concentration of > 140 mmol/l (21,705 observations) was consistently associated with lower all-cause mortality risk (adjusted HR 0,58 (0.46-0.73), <0.001), as compared to 137-139.9 mmol/l, (adjusted HR 0,74 (0.61-0.90), 0.003; 49,470 observations).
We observed a lower mortality risk in iso-, and hyponatremic patients dialyzed against higher dialysate sodium prescriptions (> 140 mmol/l).


Higher dialysate sodium concentrations are independently associated with better survival. This observational finding clearly delineates the need for high quality randomized evidence. The Randomised Evaluation of Dialysate Sodium on Vascular Events Study is currently underway to evaluate the practice of default dialysate sodium concentrations to guide policy development and improve hemodialysis outcomes.


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