workup-hyponatremia
(JASN 2012;23:1140 & 2017;28:1340; Crit Care 2013;17:206; NEJM 2015;372:55)
Workup
- History:
- acute vs. chronic (>48 h);
- sx severity;
- risk for neuro complications (alcoholism, malnourished, cirrhosis, older women on thiazides, hypoxia, hypoK)
- Measure plasma osmolality
- For hypotonic hyponatremia, ✓ volume status
- Measure Uosm
- If euvolemic and ↑ Uosm, evaluate for glucocorticoid insufficiency and hypothyroidism
- If available, consider FEUricAcid as >12% suggests SIADH (J Clinc Endo 2008;93:2991)