A Forgotten Technique of RRT for Correction of Severe Hyponatremia in CKD: Case Report

Introduction: Patients with chronic kidney disease (CKD) present electrolytes disorders. This represents a challenge when hyponatremia is below 125mmol/L associated with any criteria for urgent renal replacement therapy (RRT) with conventional hemodialysis because of higher risk of over correction above the security threshold of 10mmol/L/day and osmotic demyelination syndrome. Case Description: A 49-year-old Guatemalan female with history of 15 days of edema and slurred speech. Only history of T2DM. Was brought to the ER with BP 100/80mmHg and anasarca. Initial laboratories: negative COVID-19Ag, Cr 5.12mg/dl, (previous 2mg/dl) BUN 105mg/dl, glucose 156mg/dl, Na 108mmol/L, K 5.2meq/L, Cl 70meq/L. SOsm 224mOsm/kg, UOsm 875mOsm/kg, UNa 28meq/L. Because of neurologic symptoms, received a 150ml bolus of 3% saline twice with a rise to 112mmol/L. After the bolus, we initiated a 24-hour infusion with 3% hypertonic solution reaching a rise of Na up to 119mmol/L in 48 hours, but because of persistence of neurologic symptoms plus fluid overload >10% of body weight and hyperkalemia, we initiated RRT. In the absence of CRRT or CVVH we planned a conventional HD with blood flow of 100ml/min, dialysate flow 600ml/min, dialysate Na 130meq/L (the lowest Na possible) and 3 hours duration. After the first session had neurological and edema improvement. After two sessions with interdialytic period of 48 hours, Na control of 122mmol/L and 132mmol/L respectively with resolution of uremic syndrome. Later was diagnosed with hospitalacquired pneumonia receiving antibiotic treatment for 14 days and was discharged home with ambulatory HD. Discussion: In undeveloped countries where the access to CRRT or CVVH is unavailable, conventional modalities can be used with low blood flows and modification of the dialysate Na to a minimum (130mmol/L) offering a safe option to Na correction for patients with severe hyponatremia and any other HD criteria.