Chronic Kidney Disease USMLE Step 1 Practice Question
A 29-year-old woman develops polydipsia and polyuria 2 days after transsphenoidal pituitary adenoma resection. Vital signs show HR 98/min, BP 132/84 mmHg, RR 16/min. Serum sodium is 151 mEq/L with normal potassium. Urine osmolality is 180 mOsm/kg, and 24-hour urine output exceeds 3 liters. She denies prior diabetes mellitus. Following desmopressin administration, urine osmolality increases to 580 mOsm/kg. Which diagnosis best explains these findings?
Answer choices
- AType 4 renal tubular acidosis
- BNephrogenic diabetes insipidus
- CCentral diabetes insipidusCorrect answer
- DPrimary polydipsia
- ESIADH
- FAcute tubular necrosis
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