Severe Hyponatremia and Continuous Renal Replacement Therapy: Safety and Effectiveness of Low Sodium Dialysate

Abstract Rationale & Objective In patients with severe hyponatremia in the setting of acute kidney injury (AKI) or end stage kidney disease (ESKD), continuous renal replacement therapy (CRRT) using standard sodium (140 mEq/L) fluids may lead to excessively rapid correction of the plasma sodium concentration. Use of dialysate and replacement fluids with reduced sodium concentration can provide a controlled rate of correction of the plasma sodium concentration. Study Design We performed a single-center retrospective analysis of the safety and effectiveness of this approach in patients with a plasma sodium concentration Setting & Participants Between January 2016 and June 2018, 23 hyponatremic patients underwent CVVHDF using low-sodium dialysate and replacement fluids; 4 patients were excluded from analysis because of CRRT duration of Results The 19 patients included in the study had a mean age of 56 years, 11 (58%) were men and 15 (79%) were white (N=15). The initial mean plasma sodium level was 121 mEq/L and the initial CRRT effluent dose was 27 mL/kg/h. Only 2 patients (11%) had an increase in plasma sodium concentration of >6 mEq/L at 24 hours. The mean change in plasma sodium level at 24 and 48 hours, and at the time of CRRT discontinuation were 3, 3 and 6 mEq/L respectively. None of the patients developed osmotic demyelination syndrome. Limitations Key limitations were the small sample size and lack of a control group. Conclusions Use of low-sodium dialysate and replacement fluids is a safe strategy for the prevention of overly rapid correction of plasma sodium in hyponatremic patients undergoing CRRT.