Title of the Study: Sodium Management Tool in Hemodialysis Patients
Objectives This study aims to evaluate the impact of the Sodium Management Tool (SMT) by Fresenius on interdialytic weight gain and dialysis tolerance in hemodialysis patients. While the SMT is already in use across various dialysis centers, there is currently no systematic data collection regarding its clinical benefits.
In conventional hemodialysis, a fixed dialysate sodium concentration (typically 136-138 mmol/L) is used without adjustments during dialysis. If the dialysate sodium concentration is higher than the plasma sodium level, sodium can diffuse into the patient, leading to increased thirst and interdialytic weight gain. These factors are associated with higher mortality and an increased risk of cardiovascular events. Conversely, a negative sodium balance (dialysate sodium concentration lower than plasma sodium) can reduce plasma tonicity, increasing the risk of muscle cramps and intradialytic hypotension.
The SMT continuously measures plasma sodium concentration (once per minute) and adjusts the dialysate sodium concentration. This optimization of sodium homeostasis may reduce the occurrence of muscle cramps and hypotensive episodes during dialysis.
Methods The study will include all outpatient hemodialysis patients from the Lucerne Cantonal Hospital at the Luzern, Luzern Süd, and Sursee sites who undergo dialysis three times per week with Fresenius 6008 machines and have provided informed consent.
Participants will be randomized into two groups:
Group 1: Standard dialysis procedure in weeks 1-4, followed by dialysis with the SMT activated in weeks 5-8. The SMT will be set to 0 mmol/L, meaning the dialysate sodium concentration will be adjusted so that the plasma sodium level at the end of dialysis matches the pre-dialysis level.
Group 2: Dialysis with the SMT activated (Na 0 mmol/L) in weeks 1-4, followed by standard dialysis in weeks 5-8.
Data collection includes:
Interdialytic weight gain Pre- and post-dialysis plasma sodium levels Blood pressure before and after dialysis Bolus administration and total sodium removal Symptomatic hypotension, blood pressure drops >20 mmHg, and muscle cramps (documented by nursing staff) Dialysis tolerance and thirst perception, assessed using a visual analog scale (VAS) Patient-reported symptoms (thirst, shortness of breath, muscle cramps, dizziness, fatigue) using the Dialysis Symptom Index Extension Phase (Weeks 9-12)
For a subset of participants, the study will continue:
Subgroup A: Patients with high interdialytic weight gain will have the SMT set to -1 mmol/L. This setting aims for a plasma sodium level 1 mmol/L lower at the end of dialysis, enhancing sodium removal.
Subgroup B: Patients frequently experiencing symptoms (cramps, hypotension) will have the SMT set to +1 mmol/L. This adjustment targets a plasma sodium level 1 mmol/L higher at the end of dialysis, increasing plasma tonicity.
Outcomes Primary Outcome: Effect of the SMT on interdialytic weight gain. Secondary Outcomes: Incidence of intradialytic hypotension, muscle cramps, and specific patient symptoms (thirst, fatigue, shortness of breath, muscle cramps) measured using the Dialysis Symptom Index.
The study will be conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization (ICH-GCP) guidelines for Good Clinical Practice. All participants will provide written informed consent. Confidentiality and data protection will be maintained at all times.
