Correction of Hyper- and Hyponatraemia during Continuous Renal Replacement Therapy

Abstract

Background: Severe hyper- and hyponatraemia is associated with significant risks, yet its correction can also have serious consequences when implemented too fast or inadequately. The safe correction of serum sodium levels is particularly challenging when renal replacement therapy (RRT) is required. Methods: Using 2 case scenarios, we aim to illustrate a simple method of correcting hyper- and hyponatraemia safely by step-wise manipulation of the dialysate/replacement fluid. Results: During continuous RRT, hypernatraemia can be corrected effectively and safely by adding small pre-calculated amounts of 30% NaCl to the dialysate/replacement fluid bags aiming for a [Na⁺] in the fluid that allows safe equilibration and correction of the serum [Na⁺]. To correct hyponatraemia safely, pre-calculated amounts of sterile water can be added in a step-wise manner to achieve a fluid [Na⁺] that equals the desired target serum [Na⁺]. Conclusion: During continuous RRT, the step-wise adjustment of [Na⁺] of dialysate/replacement fluids offers a safe and reliable method to correct sodium disorders.

Correction of hyponatremia by infusing D5W (5% dextrose in water solution) prefilter in patients receiving continuous renal replacement therapy: A case series

“…Reducing the effluent rate below the recommended 20–25 mL/kg/hour means less solute clearance, which may not be optimal for many patients . Customizing dialysate or replacement sodium concentration has been done successfully but there are downsides to this approach . It requires an experienced pharmacist to compound the solution, and there are risks in compromising the sterility of the solution.…”

“…Albeit rare, ODS has been reported in patients undergoing intermittent hemodialysis. There was a case report describing a uremic patient who developed ODS after his serum sodium level was corrected by 21 mEq/L during a single 2.5 hour hemodialysis session . Multiple treatment plans have been proposed to control sodium correction with renal replacement therapy.…”

“…Various techniques have been utilized to control sodium correction with CRRT such as (1) using a reduced effluent rate, (2) adding free water to standard replacement or dialysate fluids, (3) infusing peripheral D5W, or (4) more recently, infusing D5W post‐filter of CRRT . Reducing the effluent rate below the recommended 20–25 mL/kg/hour means less solute clearance, which may not be optimal for many patients .…”

“…With continuous renal replacement therapies, various treatment plans have been proposed to control sodium correction which include adding free water to standard replacement or dialysate fluids, using a reduced effluent rate, infusing peripheral dextrose 5% solution (D5W), or more recently, infusing D5W post‐filter of CRRT . While sodium concentration with intermittent hemodialysis (iHD) can be easily adjusted to a certain degree, such as 130 mEq/L, sodium concentration of commercially available dialysate and replacement fluid is fixed at 140 mEq/L.…”

Precision Fluid Management in Continuous Renal Replacement Therapy

“…For instance, during CRRT, hypernatremia can be corrected by adding small pre-calculated amounts of a hypertonic sodium chloride solution to the dialysate/replacement fluid bags aiming for a [Na + ] in the fluid that allows safe equilibration and correction of the serum [Na + ]. Conversely, to correct hyponatremia safely, pre-calculated amounts of sterile water can be added ] [28,29] . In either case, correction of the sodium disorder can be achieved through manipulation of the sodium concentration in the dialysate, replacement solution or both and through slow, step-wise changes the desired plasma sodium concentration can be reached.…”