Syndrome of inappropriate vasopressin secretion. Studies on the mechanism of the hyponatremia in a patient.

Abstract

CONSIDERABLE interest was aroused by the report of Schwartz et al1in 1957 of two patients with hyponatremia which was attributed to secretion of antidiuretic hormone (ADH). The combination of hyponatremia and a concentrated urine which these patients manifest is by no means rare being seen in adrenal insufficiency, malnutrition, and chronic debilitating illnesses of various types. In order to establish that this combination of hyponatremia and urinary hyperosmolality results from inappropriate ADH secretion, it is necessary to exclude adrenal and renal insufficiency and to show that the serum sodium concentration can be reproducibly raised and lowered by the restriction and the forcing of excessive fluid intake, respectively. As Bower et al2have pointed out, only 20 case reports have been published since 1957 which satisfy these requirements. The validity of the suggestion by Schwartz et al that inappropriate release of vasopressin-like substance is responsible for this