Disorders of water metabolism.
Disorders of water metabolism.
复制标题
水代谢紊乱。
DOI：
10.1159/000385246
复制
发表时间：
1980
影响因子：
--
通讯作者：
V. Szatalowicz
中科院分区：
文献类型：
--
作者：
R. Schrier;V. Szatalowicz
Hyponatremia constitutes an electrolyte disorder which may occur in a wide variety of settings. For example, a low plasma sodium concentration may be present in the edematous patient with an excess of total body sodium, or in the patient with Addison's disease and a deficit of total body sodium, or in the patient with hypothyroidism or the syndrome of inappropriate antidiuretic hormone (SIADH) and near normal total body sodium. Thus, assessment of extra-cellular fluid (ECF) volume will allow categorization of the spectrum of hypo-natremic disorders into three categories (fig. 1). The urine sodium concentration will then be helpful in confirming the specific diagnosis. For example, a low urine sodium (< 10 mEq/l) should be present in the edematous patient who is retaining sodium and not receiving a diuretic. On the other hand, if a hyponatremic patient has evidence of ECF volume depletion, eg flat neck veins, orthostatic hypotension and tachycardia, dry mucous membranes and decreased skin turgor, a low urine sodium concentration (< 10 mEq/l) suggests extrarenal sodi-um losses, eg diarrhea, while a high urine sodium concentration (> 20 mEq/l) suggests renal sodium losses, eg diuretic abuse or Addison's disease. Lastly, the hyponatremic patient with no evidence of either edema or ECF volume depletion, eg SIADH or hypothyroidism, will have a urine sodium concentration which reflects the patient's intake, ie generally> 20 mEq/l. However, if these patients become ill and do not ingest sodium, then their urine sodium concentration may diminish to< 10 mEq/l. This clinical approach which focuses on the assessment of ECF volume status and urine sodium concentration should allow for appropriate diagnosis and treatment of the hyponatremic patient (5, 22). In the remainder of this paper, an attempt will be made to present the current information about the pathogenesis of the defect in water excretion which is associated with (1) edematous disorders,(2) adrenal insufficiency, and (3) thyroid disease.
