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

Patients with severe hyponatremia and renal failure who require continuous renal replacement therapy (CRRT) are at risk for overcorrection of their sodium level due to preformulated isotonic replacement or dialysate fluids. Rapid correction of hyponatremia can lead to serious neurologic complications including osmotic demyelination syndrome (ODS). There is limited data available in preventing overcorrection of severe hyponatremia with CRRT. It has been proposed to use reduced effluent volume to avoid overcorrection. However, there are instances where the CRRT prescription cannot be reduced due to other metabolic derangements. Herein, we present four cases using a calculated amount of dextrose 5% solution (D5W) prefilter as preblood pump to prevent overcorrection of hyponatremia while delivering recommended effluent volume of at least 20-25 mL/kg/hr in majority of cases. In each case, the rate of sodium correction did not exceed 8 mEq/day using D5W prefilter. Even in patients whose hyponatremia was initially overcorrected, adding calculated amount of amounts of D5W prefilter decreased the sodium level back down to prevent the risk of ODS. We also review a simplified equation to determine the D5W rate depending on the prescribed effluent volume.