Abstract: SA-PO466
Cisplatin Induced Renal Salt Wasting Syndrome: An Uncommon Diagnostic Distinction
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Case Reports
November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid‚ Electrolyte‚ and Acid-Base Disorders
- 1002 Fluid‚ Electrolyte‚ and Acid-Base Disorders: Clinical
Authors
- Suma Kumaran, Sharmil, SUNY Upstate Medical University Hospital, Syracuse, New York, United States
- Habib, Muhammad Farhan, SUNY Upstate Medical University Hospital, Syracuse, New York, United States
- Sravanthi, Metlapalli Venkata, SUNY Upstate Medical University Hospital, Syracuse, New York, United States
- Bhargava, Ramya, SUNY Upstate Medical University Hospital, Syracuse, New York, United States
Introduction
Platinum-based chemotherapy is commonly associated with nephrotoxicity and electrolyte imbalances including hyponatremia. The mechanism of hyponatremia in such cases is either syndrome of inappropriate antidiuretic hormone secretion (SIADH) or renal salt wasting syndrome (RSWS). The latter is scarcely reported. We describe a case of RSWS induced by cisplatin.
Case Description
A 20-year-old male with nonseminomatous germ cell testicular cancer for which he underwent right orchiectomy, presented with one-week history of abdominal pain, polyuria, and unintentional 15 lbs weight loss after he was initiated on adjuvant BEP (bleomycin, etoposide, cisplatin) chemotherapy. Orthostatic hypotension was noted. He appeared hypovolemic on physical examination. His urine output in the first 24 hours of monitoring was more than 5 L. Pertinent labs include low serum Na 123 mmol/L, high urine Na 173 mmol/L, and normal serum creatinine. His Fractional Na excretion (FeNa) was calculated to be 2.1%. A diagnosis of RSWS was made and he was commenced on intravenous 0.9% saline and salt tablets. His serum Na gradually normalized over two days. Considering his young age and high likelihood of cure, cisplatin was continued although subsequent chemotherapy cycles were completed inpatient with close monitoring of serum and urine sodium. RSWS did not recur on rechallenging with Cisplatin.
Discussion
Hyponatremia is a serious complication of platinum-based chemotherapy. Understanding the mechanism of hyponatremia is important as the treatments are distinct- salt supplementation in RSWS and fluid restriction in SIADH. The mechanism of RSWS is thought to be cisplatin-induced inflammation, alteration of solute transport, and apoptosis in proximal and distal tubular epithelium with preference to the former, thus causing a net sodium excretion. These patients present with hypotonic hyponatremia, polyuria, and hypovolemia. In contrast, SIADH patients are euvolemic and normouric. A high FeNa despite volume depletion helps delineate RSWS further from SIADH. Treatment consists of salt and water replenishment, and recovery is the rule although recurrence is common. While carboplatin is less toxic, cisplatin has unequivocal superiority in most of the cancers in which it is used, making it difficult to replace it, especially when there is realistic curative intent.