A 62-year-old man with stage 4 chronic kidney disease presents with diffuse bone pain and pruritus. Vital signs: BP 152/88, HR 82, RR 16, Temp 37°C, SpO2 98%. Laboratory studies reveal calcium 7.2 mg/dL, phosphate 5.8 mg/dL, PTH 612 pg/mL, and creatinine 3.4 mg/dL. Renal ultrasound shows normal kidney size without obstruction. He denies recent medication changes. Which mechanism best explains the elevated parathyroid hormone?
- A)Primary autonomous parathyroid adenoma
- B)Excess calcitriol production by the diseased kidney
- C)Destruction of parathyroid glands by autoimmunity
- D)Ectopic PTH production by renal cell carcinoma
- E)Secondary hyperparathyroidism due to phosphate retention and reduced calcitriolGABARITO
Explicação
Secondary hyperparathyroidism due to phosphate retention and reduced calcitriol is correct. Chronic kidney disease decreases phosphate excretion and impairs 1 alpha hydroxylation of vitamin D, lowering serum calcium and stimulating parathyroid hormone release.... Ver explicação completa e trilha adaptativa →