A Case of Continuous Venovenous Hemofiltration for Anuric Acute Kidney Injury With Severe Hyponatremia: A Simple Method Involving Flexible Adjustment of Sodium Replacement Solution

INTRODUCTION D ialysis therapy for patients with severe hyponatremia is challenging because rapid correction of the serum sodium concentration may lead to osmotic demyelination syndrome (ODS). Gradual correction of hyponatremia is recommended to prevent hazardous sequelae. Continuous venovenous hemofiltration (CVVH) with low-sodium replacement solution can be used to prevent rapid correction of the serum sodium concentration; however, preparation of low-sodium replacement solution by dilution is difficult and is not recommended. We developed the “FlexNa” method, which involves flexible adjustment of the sodium concentration of commercially available replacement fluid; it assures provision of CVVH without affecting the patient’s serum sodium concentration. We present a case of acute kidney injury concomitant with severe hyponatremia and hyperkalemia, which was treated successfully with CVVH using this FlexNa method.