✅The correct answer is: B.
🔺This patient with quadriparesis has a corrected calcium level of 12.9 mg/dL:
corrected calcium = measured calcium + 0.8 x (4- albumin)
12.1 + 0.8 x (4-3) = 12.1 +0.8 = 12.9 mg/dL
with symptomatic hypercalcemia (nausea, polyuria) and suppressed parathyroid hormone (PTH) level likely due to immobilization. Hypercalcemia of immobilization is likely due to increased osteoclastic bone resorption. The risk is increased in patients with a pre-existing high rate of bone turnover (eg, younger ndividuals, Paget disease). The onset of hypercalcemia is usually around 4 weeks after immobilization although patients with chronic renal insufficiency may develop hypercalcemia in as little as 3 days.
🔺 The onset of hypercalcemia due to immobilization is often insidious, and the presenting symptoms can be is nonspecific. Bisphosphonates inhibit osteoclastic bone resorption and are effective in treating hypercalcemia of immobilization and reducing the associated bone loss.
❎(Choice A) Approximately 40% of circulating calcium is bound to proteins (predominantly albumin). Hypoalbuminemia will lower the total serum calcium level; therefore, measured calcium levels are corrected upward based on he extent of hypoalbuminemia. Conversely, hyperallbuminemia is associated with an increase in total calcium. In either case, the ionized fraction is unaffected, and patients will not have calcium-related symptoms directly related to the change in albumin levels.
❎(Choices C and F) Hypercalcemia in malignancy can be due to osteolytic metastasis, secretion of PTH-related o in protein (PTHrP), or increased formation of 1,25-dihydroxyvitamin D. This patient's PTHrP and 1,25- dihydroxyvitamin D levels are low.
❎(Choice D) This patient's PTH level is suppressed, which makes primary hyperparathyroidism unlikely.
❎(Choice E) Acute rhabdomyolysis causes hypocalcemia due to precipitation of calcium and phosphorus in damaged muscles. Hypercalcemia can occur due to remobilization of calcium during the diuretic/recovery phase of the illness, often with concurrent hyperphosphatemia. However, this patient recovered from rhabdomyolysis several weeks before the onset of hypercalcemia.
💡 Educational objective:
▪️Hypercalcemia can occur in prolonged immobilization due to increased osteoclastic activity, especially in individuals with a high baseline rate of bone turnover.
▪️Bisphosphonates can reduce this hypercalcemia and prevent bone loss.
#endocrinology
#surgery
#emergency_medicine
#step2
🔺This patient with quadriparesis has a corrected calcium level of 12.9 mg/dL:
corrected calcium = measured calcium + 0.8 x (4- albumin)
12.1 + 0.8 x (4-3) = 12.1 +0.8 = 12.9 mg/dL
with symptomatic hypercalcemia (nausea, polyuria) and suppressed parathyroid hormone (PTH) level likely due to immobilization. Hypercalcemia of immobilization is likely due to increased osteoclastic bone resorption. The risk is increased in patients with a pre-existing high rate of bone turnover (eg, younger ndividuals, Paget disease). The onset of hypercalcemia is usually around 4 weeks after immobilization although patients with chronic renal insufficiency may develop hypercalcemia in as little as 3 days.
🔺 The onset of hypercalcemia due to immobilization is often insidious, and the presenting symptoms can be is nonspecific. Bisphosphonates inhibit osteoclastic bone resorption and are effective in treating hypercalcemia of immobilization and reducing the associated bone loss.
❎(Choice A) Approximately 40% of circulating calcium is bound to proteins (predominantly albumin). Hypoalbuminemia will lower the total serum calcium level; therefore, measured calcium levels are corrected upward based on he extent of hypoalbuminemia. Conversely, hyperallbuminemia is associated with an increase in total calcium. In either case, the ionized fraction is unaffected, and patients will not have calcium-related symptoms directly related to the change in albumin levels.
❎(Choices C and F) Hypercalcemia in malignancy can be due to osteolytic metastasis, secretion of PTH-related o in protein (PTHrP), or increased formation of 1,25-dihydroxyvitamin D. This patient's PTHrP and 1,25- dihydroxyvitamin D levels are low.
❎(Choice D) This patient's PTH level is suppressed, which makes primary hyperparathyroidism unlikely.
❎(Choice E) Acute rhabdomyolysis causes hypocalcemia due to precipitation of calcium and phosphorus in damaged muscles. Hypercalcemia can occur due to remobilization of calcium during the diuretic/recovery phase of the illness, often with concurrent hyperphosphatemia. However, this patient recovered from rhabdomyolysis several weeks before the onset of hypercalcemia.
💡 Educational objective:
▪️Hypercalcemia can occur in prolonged immobilization due to increased osteoclastic activity, especially in individuals with a high baseline rate of bone turnover.
▪️Bisphosphonates can reduce this hypercalcemia and prevent bone loss.
#endocrinology
#surgery
#emergency_medicine
#step2