hypocalcemia

Question 1

Q: What is hypocalcemia?

Answer 1

A: Hypocalcemia refers to a serum calcium level below the lower limit of normal, often considered below 8.5 mg/dL.

Question 2

Q: Why is calcium important in the body?

Answer 2

A: Calcium plays a vital role in cardiac muscle function and nerve signaling.

Question 3

Q: What can calcium imbalances such as hypocalcemia result in?

Answer 3

A: Abnormal cardiac rhythm and neurologic dysfunction.

Question 4

Q: What are some important causes of hypocalcemia?

Answer 4

A: Hypomagnesemia, impaired vitamin D conversion, hypoparathyroidism, and secondary hyperparathyroidism.

Question 5

Q: What initial assessment should be performed if hypocalcemia is suspected?

Answer 5

A: Perform an ABCDE assessment to determine if the patient is unstable or stable.

Question 6

Q: How should you stabilize an unstable hypocalcemic patient?

Answer 6

A: Stabilize airway, breathing, and circulation, obtain IV access, continuous vital sign monitoring, and provide supplemental oxygen if needed.

Question 7

Q: What severe symptoms might a patient with hypocalcemia experience?

Answer 7

A: Laryngospasm, seizures, or a prolonged QT interval on an ECG.

Question 8

Q: How do you treat severe hypocalcemia?

Answer 8

A: Administer intravenous calcium gluconate and consider giving IV magnesium.

Question 9

Q: What should be done for stable patients with suspected hypocalcemia?

Answer 9

A: Obtain a focused history and physical examination, and order labs, including serum calcium and magnesium levels.

Question 10

Q: What symptoms might a stable hypocalcemic patient report?

Answer 10

A: Numbness around the mouth, paresthesias of the fingers and toes, and emotional lability.

Question 11

Q: What physical exam signs can indicate hypocalcemia?

Answer 11

A: Positive Chvostek or Trousseau signs.

Question 12

Q: What is the Chvostek sign?

Answer 12

A: Tapping over the facial nerve muscles causes facial muscle spasms.

Question 13

Q: What is the Trousseau sign?

Answer 13

A: Inflating a blood pressure cuff over the arm causes a spasm of the hand.

Question 14

Q: Why should hypocalcemia be considered but not diagnosed immediately with low serum calcium levels?

Answer 14

A: Because half of the calcium in blood is bound to plasma proteins like albumin, and ionized calcium reflects the body’s stores more accurately.

Question 15

Q: How do you calculate the corrected total serum calcium level?

Answer 15

A: Subtract serum albumin from 4, multiply the difference by 0.8, then add the product to the measured serum calcium.

Question 16

Q: What should be checked after diagnosing hypocalcemia?

Answer 16

A: Review the serum magnesium level.

Question 17

Q: What does low serum magnesium indicate in hypocalcemia?

Answer 17

A: Hypocalcemia due to magnesium deficiency, as magnesium is essential for PTH production.

Question 18

Q: What labs should be ordered if serum magnesium is normal in hypocalcemia?

Answer 18

A: A basic metabolic panel, serum PTH, and 25-hydroxy vitamin D.

Question 19

Q: What does elevated serum creatinine indicate in hypocalcemia?

Answer 19

A: Impaired conversion of vitamin D to its active form due to impaired renal function.

Question 20

Q: What does low 1,25-dihydroxy vitamin D suggest?

Answer 20

A: Hypocalcemia due to impaired conversion of vitamin D to its active form.

Question 21

Q: What should be checked if serum creatinine is normal in hypocalcemia?

Answer 21

A: Check PTH levels.

Question 22

Q: What does low or normal PTH indicate in hypocalcemia?

Answer 22

A: Hypoparathyroidism, often iatrogenic or due to autoimmune disorders.

Question 23

Q: What is autosomal dominant hypocalcemia?

Answer 23

A: A genetic disorder with a mutation in the calcium-sensing receptor causing low PTH secretion.

Question 24

Q: How do you screen for autosomal dominant hypocalcemia?

Answer 24

A: Check urine calcium to creatinine ratio and consider genetic testing if elevated.

Question 25

Q: What does elevated PTH indicate in hypocalcemia?

Answer 25

A: Secondary hyperparathyroidism, consider vitamin D deficiency or impaired vitamin D activity.

Question 26

Q: What should be assessed if PTH is elevated in hypocalcemia?

Answer 26

A: Assess 25-hydroxy vitamin D levels.

Question 27

Q: What does low 25-hydroxy vitamin D indicate?

Answer 27

A: Vitamin D deficiency.

Question 28

Q: What should be considered if 25-hydroxy vitamin D is normal in hypocalcemia?

Answer 28

A: Pseudohypoparathyroidism, a rare genetic condition with end-organ resistance to PTH.

Question 29

Q: How do you confirm a diagnosis of pseudohypoparathyroidism?

Answer 29

A: Order genetic testing.

Question 30

Q: What is a common cause of secondary hyperparathyroidism?

Answer 30

A: Chronic kidney disease, leading to defects in vitamin D activation and resulting in hypocalcemia and hyperphosphatemia.

Question 31

Q: What are some important causes of hypocalcemia?

Answer 31

A: Hypomagnesemia and impaired vitamin D conversion to its active form.

Question 32

Q: What should be done if hypocalcemia due to magnesium deficiency is ruled out?

Answer 32

A: Assess PTH levels.

Question 33

Q: What does low or normal PTH indicate?

Answer 33

A: Hypoparathyroidism.

Question 34

Q: What does elevated PTH indicate?

Answer 34

A: Secondary hyperparathyroidism, assess 25-hydroxy vitamin D levels.

Question 35

Q: What does normal 25-hydroxy vitamin D suggest in hypocalcemia?

Answer 35

A: Pseudohypoparathyroidism.