The Management of Postoperative Diabetes Insipidus

T HE usual response to a major surgical procedure is temporary oliguria which persists for several days. 1,3,~2,17 The secretion of antidiuretic hormone (ADH) tha t produces this oliguria is, in a sense, an inappropria te secretion, in tha t it is not controlled by osmotic stimuli. After surgical nlanipulation in the sellar and suprasellar areas, however, the supraopt ico-hypophyseal system may be temporarily or permanent ly damaged, so that a t ransient or permanent diabetes insipidus results. The coexistence of uncontrolled polyuria with postoperat ive sodium retention, or with possible excessive sodium loss in pat ients with prolonged hypopituitarism, may make the management of these patients very difficult. Two cases will be described to illustrate some of these problems. In the charts illustrating these cases, crude water balance indicates only fluid intake and urine output . Insensible fluid loss, water of oxidation, and water in the food are not indicated. However, when this balance is considered along with changes in body weight, a good first approximation of the actual water balance can be made. Corrected serum sodium concentration, or osmolality, indicates the ratio between body water and body electrolytes and tends to va ry directly with changes of exchangeable electrolytes and inversely with changes of total body water? ,9