Today our residents were quickly on point in recognizing that a patient with recurrent falls and nausea needed to be evaluated for an intracranial abnormality, who was found to have a subacute subdural hematoma and hyponatremia.
A learning point we discussed, was that with hyponatremia and a brain bleed, managing SIADH with fluid restriction should be prioritized over fluid administration to treat cerebral salt wasting. This is based mostly on epidemiology of SIADH being far more common the CSW (Hannon et al Jan 2014 JCEM).
This 2007 NEJM article is a fantastic reference on SIADH, and it's essential features which include:
-Decreased effective osmolality (<275 mOsm/kg of water)
-Urine Osms >100
-Urine Sodium >40
-Normal thyroid and adrenal function
-No recent diuretics