Abstract: TH-PO1128

Rate of Cisplatin Salt Wasting (CSW)

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 704 Fluid, Electrolyte, Acid-Base Disorders

Author

  • Latcha, Sheron, Memorial Sloan Kettering Cancer Center, New York, New York, United States
Background

CSW likely results from cisplatin injury to the proximal renal tubules, the major site of sodium and water reabsorption. Up to 10% of patients developed CSW in early clinical studies with cisplatin. Subsequently, CSW has only been rarely reported. The rate of CSW may have declined due to agressive hydration with normal saline (NS), which is renoprotective, or it may be due to under recognition and therefore under reporting of CSW.

Methods

We obtained retrospective data on adult patients who received cisplatin from 1/1/2014-12/34-2015 who met the following criteria: sodium <135mEq/l, received IV normal saline (NS) >24H after cisplatin administration, and diagnosis codes for hypotension, polyuria, dehydration, hypovolemia or shock. A nephrologist randomly reviewed the medical record of 35% of episodes, and determined if the patient had SIADH, dehyration, CHF, CSW or other cause for to explain the criterion outlined above. The diagnosis of CSW was based on the findings of hypotension, nocturia, polyuria with the absence of other causes of dehydration (decreased oral intake, infection,diarrhea).

Results

652 patients and 829 hyponatremic episodes were identified; 300 episodes in 230 patients were reviewed; 48 episodes were removed from analysis (record incomplete, duplicates)/ 252 episodes were analyzed. CSW was identified in 8 (3.2%) epispodes, dehydration in 111 (44%), SIADH in 86 (34.1%) and CHF 11 (4.4%). Urine sodium and osmolarity were checked in 41 (16%) and renal consults in 5 (2%) episodes. With the exception of episodes of CHF, hyponatremia was empirically treated with IV NS, even when patients were normotensive, and had no tachycardia or edema. Patients were not asked for symptoms of polyuria, nocturia or thirst.

Conclusion

CSW is likely underdiagnosed and underreported. Nausea is most often interpreted as a cause of dehydration as opposed to a symptom of hyponatremia itself and patients complaining of dizziness and lightheadness are assumed to have dehydration from decreased oral intake. Patients were not specifically questioned about symptoms of CSW, specifically polyuria, nocturia or thirst . Orthostatic blood pressure reading, and urine and serum sodium and osmolarity are rarely used to evaluate hyponatremia. Consequently, patients with CSW may remain hyponatremic because they are not receiving adequate hydration, and patients with SIADH are inappropriately receiving IVF.