This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Search for Related Content Social Bookmarking                         What's this?

The hyponatremic patient: A systematic approach to laboratory diagnosis

Hyponatremia (serum sodium < 134 mmol/L) is a common electrolyte disturbance. A history of concurrent illness and medication use as well as the assessment of extracellular volume status on physical examination may provide useful clues as to the pathogenesis of hyponatremia. Measurement of the effective serum tonicity is the first step in the laboratory evaluation. In patients with normal or elevated effective serum osmolality (280 mOsm/kg or greater) pseudohyponatremia should be excluded. In the hypo-osmolar state, urine osmolality is used to determine whether water excretion is normal or impaired. A urine osmolality value of <100 mOsm/kg indicates complete and appropriate suppression of antidiuretic hormone secretion. A urine sodium level <20 mmol/L is indicative of hypovolemia, whereas a level >40 mmol/L is suggestive of the syndrome of inappropriate antidiuretic hormone secretion. Levels of hormones (thyroid-stimulaing hormone and cortisol) and arterial blood gases should be determined in difficult cases ofhyponatremia. A clinical diagnostic algorithm for hyponatremia is included in this review article.

Nutrition in Clinical Practice, Vol. 18, No. 1, 104-105 (2003)
DOI: 10.1177/0115426503018001104c


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?