Articles on Medical Diseases and Conditions

Entries Tagged ‘Hyponatremia’

Laboratory Investigation of Hyponatremia

When the serum sodium level is unexpectedly low, one must determine whether it is due to false (artifactual) hyponatremia, sodium depletion, hemodilution, the IADH syndrome, or the reset osmostat syndrome. The first step is to rule out artifactual causes. The serum sodium tests should be repeated and blood redrawn if necessary, avoiding areas receiving IV […]

Disorders Simulating Inappropriate Antidiuretic Hormone

Refractory dilutional syndrome is a moderately frequent condition in which many features of IADH are seen but the classic syndrome is not present. The dilutional hyponatremia of cirrhosis and congestive heart failure may sometimes be of this type, although usually other mechanisms can better account for hyponatremia, such as overuse of diuretics. However, in some […]

Hyponatremic Depletional Syndromes

In protracted and severe vomiting, as occurs with pyloric obstruction or stenosis, gastric fluid is lost in large amounts and a hypochloremic (acid-losing) alkalosis develops. Gastric contents have a relatively low sodium content and water loss relatively exceeds electrolyte loss. Despite relatively low electrolyte content, significant quantities of electrolytes are lost with the fluid, leading […]

Hyponatremia. Iatrogenic Sources of Hyponatremia

Diuretic therapy and administration of IV hypotonic fluids (dextrose in water or half-normal saline) form very important and frequent etiologies for hyponatremia, either as the sole agent or superimposed on some condition predisposing to hyponatremia. In several studies of patients with hyponatremia, diuretic use was considered to be the major contributing factor or sole etiology […]

Serum Sodium Abnormalities

The most frequent electrolyte abnormalities, both clinically and as reflected in abnormal laboratory values, involve sodium. This is true because sodium is the most important cation of the body, both from a quantitative standpoint and because of its influence in maintaining electric neutrality. The most common causes of low or high serum sodium values are […]