- inappropriate sodium wasting in the urine in the setting of acute disease in central nervous system (CNS), usually subarachnoid hemorrhage
- less common cause of hyponatremia than SIADH
- release of BNP [brain natriuretic peptide] / diminished CNS sympathetic activity –>
- impaired Na reabsorption –>
- volume depletion, inc ADH release, hyponatremia, inc neurologic injury
- low Na
- low serum osm
- high urine osm [inappropriate] [>100 mosm/Kg; usually >300]
- low serum uric acid [urate wasting in urine]
Treatment: In patients with a clinical picture compatible with CSW, treatment should begin with isotonic saline to correct the volume depletion and possibly reverse the hyponatremia
- Patients with severe symptoms should be treated in the ICU with hypertonic saline and fludrocortisone.
- Acute hyponatremia and/or severe symptoms should have 6 mmol/L corrected over 6 h or until severe symptoms improve.
- The total correction of Na should not exceed 8 mmol/L over 24 h. Therefore, if 6 mmol/L is corrected in 6 h, the Na should not be increased more than 2 mmol/L in the following 18 h.
- The total correction of Na is based on the Na deficit which is calculated conservatively with the formula depicted.
- With improvement of symptoms, the patients can be moved to the less aggressive treatments in the algorithm, until Na reaches 131 mmol/L.
- SAH patients are an exception and receive treatment even for a serum Na of 131–135 mmol/L.
*HHH hypervolemia, hypertension, hemodilution (NOT RECOMMENDED ANYMORE); IMC intermediate care unit, U urine,
Uptodate.com,. “Cerebral Salt Wasting”. N.p., 2015. Web. 14 Dec. 2015.
Layon, A. Joseph, Andrea Gabrielli, and William A Friedman. Textbook Of Neurointensive Care. Print.