RESUMO
Nephrogenic diabetes insipidus (NDI) presents a rarely encountered but challenging fluid management problem in the perioperative period. This case is that of a patient with a perforated duodenal ulcer and previously undiagnosed NDI who received standard preoperative and postoperative hydration with normal saline, causing hypernatremia and an inappropriate diuresis. The resulting hypernatremia and hyperosmolality required aggressive hypotonic fluid replacement to return to preoperative values. Though refractory to 1-desamino-8-D-argenine-vasopressin (dDAVP), thiazide diuretics and nonsteroidal anti-inflammatory agents have a role in managing selected patients. Early diagnosis with careful fluid and electrolyte management are critical in successful management of these patients in the perioperative period.