Pituitary Disorders USMLE Step 1 Practice Question
A 19-year-old woman underwent transsphenoidal pituitary surgery for a Rathke cleft cyst 1 month ago. She now presents with sudden-onset polydipsia, polyuria (6 L/day), and nocturia. Vital signs show BP 118/76, HR 88, RR 16, Temp 37°C. Labs reveal plasma osmolality 295 mOsm/kg, urine osmolality 95 mOsm/kg, and serum sodium 142 mEq/L. She denies fever or headache. Which intervention is most appropriate immediately?
Answer choices
- AObservation without intervention; symptoms typically resolve spontaneously
- BHyperetonic saline infusion
- CFluid restriction to 1 liter per day
- DDesmopressin (DDAVP) replacement therapyCorrect answer
- EThiazide diuretics to reduce polyuria
- FVasopressin infusion to restore endogenous ADH production
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