Diagnostic Dilemma SIADH vs. RSW
Both characterized by:
Association with intracranial diseases
Hyponatremia
Concentrated urine
Urinary (Na) usually>20 mEq/L
Normal renal/adrenal/thyroid function
Nonedematous
Hypouricemia
Increased FE urate
Only difference is volume status
Table 1: Common findings in SIADH and RSW that complicate differentiation of SIADH from RSW.