Table 3.

Diagnostic criteria for the diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH) [32,33].

1. Hyposomolality; plasma osmolality <280 mOsm/kg

2. Inappropriate urinary concentration (Uosm >100 mOsm/kg)

3. Patient is clinically euvolemic

4. Elevated urinary sodium (>40 mmol/L), with normal salt and water intake

5. Exclude hypothyroidism and glucocorticoid deficiency―particularly in patients with neurosurgical conditions