Studies of Electrolyte Metabolism in 2 Patients With Pituitary Insufficiency*

THE relative ease and accuracy of sodium and potassium determinations made possible by the introduction of the flame photometer a few years ago has led to intensified interest in the electrolyte metabolism in a variety of diseases. In this clinic, as elsewhere, investigators have been repeatedly confronted with the problem, of edema formation in the presence of low serum electrolyte concentrations. This was first noted by us in 2 patients with Addison's disease. At the time of these observations, both patients were receiving added salt and desoxycorticosterone. It is well known that either of these agents in excess will produce edema in patients with this disease, but the simultaneous observation of low serum electrolyte levels seemed somewhat unusual. Furthermore, in spite of chloride levels as low as 80 milliequivalents per liter, neither patient showed signs of intravascular dehydration or circulatory inadequacy. Other clinics have reported low concentrations of serum electrolytes in certain cases of congestive heart failure (1, 2) and of cirrhosis of the liver (3, 4). The same phenomenon has been observed here and the administration of saline, even in hypertonic solution, has resulted primarily in the expansion of the extracellular fluid, without increasing the serum sodium concentration to normal levels.