calcium metabolism Flashcards
In the evaluation of hypercalcemia, the first step is to determine if the
intact PTH level is inappropriately normal/high or appropriately suppressed.
In the outpatient setting, primary hyperparathyroidism (PHP) due to a __________________ is the most common etiology. Most patients are asymptomatic. Kidney and bone evaluation, both biochemical and imaging, are performed to determine need for treatment. Surgery is the treatment of choice. Indications for it include age under 50, osteoporosis, fragility fractures, kidney stones, eGFR under 60 and calcium level 1 mg/dl over the upper end of normal.
In the outpatient setting, primary hyperparathyroidism (PHP) due to a parathyroid adenoma is the most common etiology. Most patients are asymptomatic. Kidney and bone evaluation, both biochemical and imaging, are performed to determine need for treatment. Surgery to remove the adenoma (parathyroidectomy) is the treatment of choice. Indications for parathyroidectomy include age under 50, osteoporosis, fragility fractures, kidney stones, eGFR under 60 and calcium level 1 mg/dl over the upper end of normal.
Accidental removal of ______________ is a major complication of thyroidectomy, especially for multinodular goiters
parathyroids
The major cause of asymptomatic hyperparathyroidism is a ____________
solitary adenoma.
Adenomas consist of _____ cells and/or ______ cells, usually contain no f____, and may be associated with a _____________.
Adenomas consist of chief cells and/or oxyphil cells, usually contain no fat, and may be associated with a compressed rim of normal parathyroid.
Parathyroid hyperplasia and/or neoplasia is a major component of __________ (up to ~80% of patients, often severe disease), a minor component of _________ (only ~30% of patients, usually mild disease) and not present in __________.
Parathyroid hyperplasia and/or neoplasia is a major component of MEN1 (up to ~80% of patients, often severe disease), a minor component of MEN2A (only ~30% of patients, usually mild disease) and not present in MEN2B.
Familial hypocalciuric hypercalcemia (FHH) arises from a mutation in the _______________________. It is a benign disorder that does not require treatment. The clinical presentation of FHH mimics ___________________, and it is therefore important to recognize to prevent unnecessary parathyroidectomy.
Familial hypocalciuric hypercalcemia (FHH) arises from a mutation in the calcium sensing receptor (CaR). It is a benign disorder that does not require treatment. The clinical presentation of FHH mimics primary hyperparathyroidism, and it is therefore important to recognize to prevent unnecessary parathyroidectomy.
Among hospitalized patients with ____________, malignancy is the most common etiology. Humoral mechanisms account for the majority of malignancy-related ___________. Most patients are symptomatic and the presence of ____________ generally suggests a poor prognosis.
** all the same word
hypercalcemia
Treatment of hypercalcemia is aimed at lowering the calcium level (if the patient is symptomatic) and managing the underlying cause. Treatment for acute hypercalcemia includes (2)
hydration followed by a loop diuretic and agents that inhibit bone resorption (such as bisphosphonates).
In the evaluation of hypocalcemia, determine if the intact __ is inappropriately low or appropriately elevated.
PTH
Symptoms and signs of acute hypocalcemia are _______ and_______ in origin. ______ sign elicits carpo-pedal spasm. ________ sign elicits ipsilateral contractions of the facial muscle.
Symptoms and signs of acute hypocalcemia are neuromuscular and cardiac in origin. Trousseau’s sign elicits carpo-pedal spasm. Chvostek’s sign elicits ipsilateral contractions of the facial muscle.
The causes of hypocalcemia are due to PTH deficiency or resistance, vitamin D deficiency or resistance or complexation of calcium. The most common etiology of hypocalcemia is ______________
surgery in the neck (total thyroidectomy or parathyroidectomy).
Acute hypocalcemia is a medical emergency. Treatment of acute hypocalcemia requires _______________, while treatment of chronic hypocalcemia requires ______________________.
Acute hypocalcemia is a medical emergency. Treatment of acute hypocalcemia requires appropriate amounts of IV calcium, while treatment of chronic hypocalcemia requires oral calcium co-administered with the active form of vitamin D.
Use when major alterations in serum albumin or plasma proteins are present to confirm calcium abnormality
Ionized calcium concentration
Can be affected by changes in volume status and plasma protein concentration
Use albumin to correct for such changes
Total calcium concentration
