Calcium and Parathyroid USMLE Step 1 Practice Question
A 42-year-old man with a history of neck trauma presents with acute-onset severe neck pain and swelling. Vital signs show BP 128/82, HR 92, RR 16, Temp 37.2°C, SpO2 98%. Intraoperative findings reveal a cystic parathyroid gland with hemorrhage. Postoperatively, serum calcium is 7.8 mg/dL (normal 8.5-10.5) with PTH 8 pg/mL (normal 15-65). No tetany is observed. Which pathophysiology best explains the acute hypocalcemia?
Answer choices
- AAcute kidney injury from surgical hypotension
- BTransfusion-related citrate toxicity
- CVitamin D deficiency uncovered by surgery
- DSurgical hypoparathyroidism from inadvertent removal of all parathyroid tissueCorrect answer
- EHungry bone syndrome from rapid bone remineralization
- FAcute hyperphosphatemia from tumor lysis syndrome
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