Disorders of the Parathyroids Flashcards
what is the most common cause of acquired hypoparathyroidism?
post-surgical of thyroid, parathyroid, or radical neck surgery
what is the cause of hypoparathyroidism that is associated with function?
low magnesium
parathyroids need magnesium to function
what is the hallmark presentation of acute hypoparathyroidism? why?
tetany
hypocalcemia
twitch of the facial muscles when gently tapping an individuals cheek
chvostek sign
spasm of hand induced by inflation of a BP cuff around the arm
Trousseau sign
a patient presents with chvostek sign, trousseau sign, muscle cramps, stridor, cramps in hands and feet, seizures, and hyperactive deep tendon reflexes. what are they likely experiencing?
severe tetany due to hypopharathyroidism
why would we order a total calcium AND a corrected calcium?
low calcium may be due to hypoalbuminemia
we want to only look at unbound calcium
what would labs in a patient with hypoparathyroidism look like? PTH, serum calcium, serum phosphate, urinary calcium, magnesium.
low PTH
low serum total calcium
high serum phosphate
low urinary calcium
+/- low magnesium
what is the emergency treatment for patients with + chvostek/trousseau seizures, arrhythmias, and calcium less than 7.5? (5)
airway
IV calcium
oral calcium ASAP
vitamin D
magnesium
what is the goal in treating mild cases of hypoparathyroidism?
relieve symptoms + maintain serum Ca low-normal to avoid hypercalciuria
what is the treatment for a patient with mild hypoparathyroidism? (3)
oral calcium
oral vit D (calcitriol)
+/- magnesium
what medication can patients take if they have a severe case of hypoparathyroidism, but are not responsive to initial treatment?
Teriparatide (synthetic human PTH) - SubQ
how often should we monitor urinary/serum calcium and serum phosphate after treating a patient for hypoparathyroidism? (2)
weekly until stable serum calcium
3-6 month intervals
what is our first concerning sign after treating a patient for hypoparathyroidism?
what can it lead to? (3)
hypercalciuria
nephrolithiasis
nephrocalcinosis
renal failure
where does the problem occur in primary hyperparathyroidism?
parathyroid glands
what is the most common cause of primary hyperparathyroidism?
single parathyroid adenoma
what is the second most common cause of primary hyperparathyroidism?
hyperplasia of 2+ parathyroid glands
what is the most common cause of asymptomatic hypercalcemia?
primary hyperparathyroidism
what are some possible consequences of asymptomatic hypercalcemia? why?
hypercalcuria + renal calculi
renal tubules unable to reabsorb all the calcium
what is the relationship between PTH and bones?
PTH stimulates osteoclasts to break down bone
what does excessive PTH lead to, in relation to bones?
cortical demineralization
where in the body is cortical demineralization most common in?
hip and wrist
where does the problem occur in secondary/tertiary hyperparathyroidism?
kidney
what is the major cause of secondary/tertiary hyperparathyroidism?
chronic kidney disease
what occurs in chronic kidney disease to cause hyperparathyroidism? (secondary)
kidneys cannot reabsorb calcium
increased PTH secretion in an attempt to create more calcium
what occurs in secondary hyperparathyroidism?
parathyroid stimulation + enlargement
what occurs in tertiary hyperparathyroidism?
parathyroid glands act as an adenoma, not responding to any levels of calcium - just continue dumping PTH
a patient presents with low bone density, arthralgias, nephrolithiasis, abdominal groans, fatigue, depression, weakness, and bradycardia. what are they likely experiencing?
hyperparathyroidism
what would labs look like in primary hyperparathyroidism? (4)
elevated serum/urine calcium
elevated PTH
low-normal serum phosphate
normal-elevated Alk Phos
what does an elevated Alk Phos mean?
increased bone breakdown due to increased PTH = stimulating osteoclast activity
what would labs look like in secondary hyperparathyroidism? (2)
low-normal serum calcium
elevated PTH
when is imaging for hyperparathyroidism indicated?
pre-op to visualize adenomas
what imaging is used to view osteopenia, cystic lesions, brown tumors, and salt and pepper skull in hyperparathyroidism?
xray
what imaging is used to view nephrolithiasis in hyperparathyroidism?
ultrasound
what imaging is used to determine bone loss in hyperparathyroidism?
DXA scan
what is the treatment for a patient with hyperparathyroidism that is symptomatic or meets the asymptomatic guidelines?
parathyroidectomy
what is the treatment for a patient with hyperparathyroidism that is symptomatic but a poor surgical candidate?
cinacalet - severe hypercalcemia
what drug can be added for a patient with hyperparathyroidism that has osteoporosis?
bisphosphonates
what are 3 things a patient with hyperparathyroidism should avoid?
thiazide diuretics
calcium supplements
immobilization/bed rest
what can be reversed when primary hyperparathyroidism is cured? (2)
osteoporosis
osteopenia
