Table compares clinical and laboratory findings in CSW vs SIADH. Both conditions will present with low serum (osm and Na) and high urine (osm and Na). The key to distinguishing between the two is extracellular fluid status (increased or normal in SIADH and decreased in CSW).
SIADH criteria proposed by Janicic and colleagues:
- Posm <275
- inappropriate urinary concentration (Uosm >100)
- clinical euvolemia (no orthostasis, tachycardia, dec skin turgor, dry mucous membranes or edema and ascites)
- elevated urinary Na excretion with normal salt and water intake
- absence of other causes of euvolemic hypoosmolality (hypothyroidism, hypocortisolism)
Layon, A. Joseph, Andrea Gabrielli, and William A Friedman. Textbook Of Neurointensive Care. Print.