A woman strikes her head in a car crash and is admitted to the hospital, where she begins urinating up to 1 L every few hours and complaining of constant thirst.Which of the following is the most appropriate treatment?

Desmopressin

16. The correct answer is B. Desmopressin (dDAVP) is 1-deamino-8-D-arginine vasopressin, an analog of ADH. This woman has central DI caused by trauma to the posterior pituitary. This inhibits secretion of ADH. Repleting her ADH is the most appropriate therapy of the options given. If dDAVP is chosen, the patients sodium and fluid status should be carefully monitored, because acute trauma to the posterior pituitary can lead to a triphasic response. In phase 1, the injured pituitary ceases secretion of ADH, resulting in the clinical picture presented in the question stem. In phase 2, the death of pituitary tissue causes the release of ADH stores, leading to fluid retention and hyponatremia consistent with the syndrome of inappropriate ADH secretion. Phase 3 arises from permanent damage to the posterior pituitary, resulting in persistent central diabetes insipidus. Answer A is incorrect. Demeclocycline is used to treat the syndrome of inappropriate ADH secretion. This compound acts to inhibit ADH action and would exacerbate her condition. Answer C is incorrect. Furosemide is a loop diuretic and is likely to exacerbate her condition. Answer D is incorrect. Insulin is an inappropriate treatment. Central DI shares only the symptoms of polydipsia and polyuria with diabetes mellitus. The treatments and causes are completely different. Answer E is incorrect. Mannitol is an osmotic diuretic that would exacerbate her condition.