genitourinary disorders
Nephrogenic Diabetes Insipidus
Key Points
Patients with NDI are unable to concentrate urine due to impaired renal tubule response tovasopressin. They typically pass large volumes of dilute urine, are appropriately thirsty and have near-normal serum sodium levels. Minimize preventable neurologic sequelae by considering inherited NDI in infants with polyuria or affected family members. Measure 24-hour urine volume and osmolality and serum electrolytes. Confirm the diagnosis with a water deprivation test. Ensure adequate free water intake, restrict dietary salt and protein, and use a thiazide diuretic oramilorideas needed. 