"Pleurex Desalination" in Malignancy-related Ascites: A Novel Mechanism of Hyponatremia.

OBJECTIVE: Pleurex catheters are a form of palliative therapy for patients, offering relief from symptomatic ascites while also affording greater independence and flexibility; however, aggressive drainage can lead to significant total body sodium losses. We describe the course of patients with "Pleurex desalination," an under-appreciated cause of hypovolemic hyponatremia, highlighting its unique pathophysiology and providing recommendations on how to manage these complex patients. PATIENTS AND METHODS: We included representative patients with "Pleurex desalination" who were evaluated and treated by the renal consult service at Brigham and Women's between 2017 and 2019. RESULTS: We identified 3 patients who were hospitalized with "Pleurex desalination" and had complete data on serum and urine studies, as well as treatment course. We demonstrate that patients with "Pleurex desalination" were removing up to 1 to 2 L of ascitic fluid a day and were admitted with signs and symptoms of profound hypovolemia and hyponatremia. Patients worsened with administration of diuretics and salt restriction and improved with aggressive fluid resuscitation in the form of hypertonic saline, normal saline, and/or intravenous albumin. CONCLUSION: "Pleurex desalination" is an under-recognized cause of hyponatremia; at-risk patients require close observation and periodic resuscitation with intravenous, volume-expanding fluids.