parathyroid Flashcards
PTH 3 functions
- mobilize calcium from bones by osteoclast stimulation
- stimulates kidneys to resorb calcium
- increases GI absorption of calcium
- what causes 85% of primary hyperparathyroidism
- other 15%
- benign parathyroid gland adenomas
- parathyroid gland hyperplasia
hyperparathyroidism
- gender
- age
women 2:1 ratio
incidence increases after age 50
what occurs with chronic kidney disease and why
secondary hyperparathyroidism occurs due to hyperphosphatemia, causing increased ionized calcium levels, and decreased renal production of active vitamin D
mild hypercalcemia symptoms
asymptomatic
thirst, anorexia, depressed DTR, N/V, abd pain, constipation, fatigue, anemia, wt loss, peptic ulcer disease, pancreatitis, HTN
severe hypercalcemia symptoms
stones, bones, groans, moans
- renal loss of Ca and phosphate= kidney stones
- bone loss from PTH= pain in bones
- increase GI absorption and abd cramps= groans
- irritability, psychosis, depression= moans
pathologic fractures occur where usually
jaw
hypercalcemia induced nephrogenic diabetes insipidus symptoms
polydipsia and polyuria
hypercalcemia in relation to urine calcium
urine calcium excretion is low for hypercalcemia
what labs confirm hyperparathyroidism
elevated serum levels of intact PTH
what labs confirm a secondary disorder of PTH such as malignancy
elevated calcium with low PTH
what labs indicate parathyroid cancer
extreme elevations of both calcium and PTH
what to do before treating hyperparathyroidism
screen for familial benign hypocalciuric hypercalcemia with a 24 hr urine for calcium and creatinine
pts with low bone mineral density, normal serum calcium, elevated PTH
should be assessed for secondary hyperparathyroidism from vitamin D or calcium deficiency, hyperphosphatemia, or renal failure
EKG with hyperparathyroidism
prolonged PR interval, shortened QT interval, bradyarrhymias, heart block, asystole
treatment for mild asymptomatic primary hyperparathyroidism
stay active, avoid immobilization, drink adequate fluids
hyperparathyroidism pts should avoid what
thiazides, large doses of vitamin A and D, and calcium containing antacids, and supplements
monitor hyperparathyroidism with what tests
serum calcium serum albumin kidney function urinary calcium excretion bone density studies
what can temporary measure to decrease serum calcium
bisphosphonates; with cautious administration of vitamin D
acute hypercalcemic crisis
IV hydration and bisphosphonates; furosemide may promote urinary calcicum excretion
- tx for symptomatic primary disorder-hyperparathyroidism
- what can occur post operatively
- parathyroidectomy
- hypocalcemia and transient hyperthyroidism may occur post op
hypercalcemia symptoms
proximal muscle weakness, gait disturbances, atrophy, hyperreflexia
acquired hypoparathyroidism most commonly from what
following parathyroidectomy or thyroidectomy
heavy metal toxicity can cause what
hypoparathyroidism
hypomagnesium can cause what
hypoparathyroidism
What is DiGeorge syndrome
congenital cause of hypocalcemia arising from parathyroid hypoplasia, thymic hypoplasia and outflow tract defects of the heart
congenital pseudohypoparathyroidism results from what
a group of disorders characterized by alterations in serum calcium related to resistance to PTH
tetany, carpopedal spasms, mm or abd cramps, paresthesias as well as teeth, nail, and hair defects, HYPERreflexia
hypocalcemia
hypocalcemia signs
tetany, carpopedal spasms, mm or abd cramps, paresthesias as well as teeth, nail, and hair defects, HYPERreflexia
chvostek sign
contraction of eye, mouth, nose muscles, elicted by tapping along the course of the facial nerve anterior to the ear
trosseau sign
produces spasm in the hand and wrist with compression to the forearm
lethargy, anxiety, parkinsonism, mental retardation, personality changes, blurred vision caused by cataracts
severe chronic hypoparathyroidism
hallmark to hypoparathyroidism
decreased PTH and adjusted serum calcium, and increased phosphate levels
[serum magnesium may be low, alk phos nml]
EKG in hypoparathyroidism
prolonged QT intervals and t wave abnormalities
radiographs in hypoparathyroidism
chronic increased bone mineral density, especially in the lumbar spine and skull
hypoparathyroidism tx
correct hypocalcemia with Ca and Vit D. Mag supp may be required
how to monitor tx of hypoparathyroidism
measurement of adjusted serum and urine calcium levels
avoid what drugs with hypoparathyroidism
phenothiazines and furosemide due to risk of further calcium loss
what is emergency tx of tetany
airway maintenance and slow administration of IV calcium gluconate
An adenoma of the parathyroid does what
An adenoma leads to excessive secretion of parathyroid hormone.
Chronic renal failure and poor production of vitamin D which will cause what
Chronic renal failure and poor production of vitamin D which will decrease Calcium, thereby stimulating the parathyroid glands
hyperparathyroidism
Blood work
Ca > 10.5
elevated PTH is diagnostic
phosphate low less <2.5 in primary disease. Elevated in secondary disease
low vitamin D
hyperparathyroidism
Urine
Ca elevated
phosphate elevated
hyperparathyroidism
Imaging
- CT/ MRI not helpful
- U/S is far more sensitive though not necessary
- X-ray: demineralization
subperiosteal bone resorption especially in the fingers
cysts of the jaw; salt and pepper skull - DXA scan may help determine amount of bone loss
hyperparathyroidism surgical tx
Surgical removal 94% successful
parathyroidectomy is the recommended treatment for symptomatic and some asymptomatic patients
complication of parathyroidectomy
hypocalcemia
Hyperthyroidism and hyperparathyroidism
Hyperthyroidism may result from physical manipulation of the thyroid- propranolol if necessary
Medical treatment of hyperparathyroidism
Fluid, Fluid, Fluid — admission and IV fluid if necessary
IV Bisphosphonates
Pamidronate
Zoledronic Acid
Cinacalcet — a calcimimetic
Vitamin D
Estrogen decreases serum Ca in a postmenopausal hyperparathyroidism
Propranolol may be used to protect the heart against elevated Ca
Heavy metal damage Low Mg Granulomas Tumors Infection Reidel’s thyroiditis Post thyroidectomy is the most common Post parathyroidectomy
can all cause hypoparathyroidism
Autoimmune hypoparathyroidism
may occur alone in combination with other autoimmune disorders like lupus or Addison’s disease.
irritability tetany — the involuntary contraction of muscles carpopedal spasms cramping convulsions tingling circumoral distal extremities
acute hypoparathyroidism
Lethargy parkinsonism mental retardation anxiety changes in personality cataracts → blurred vision dry skin decreased eyebrow hair Nail and teeth defects — brittle nails hyperreflexia (possible)
chronic hypoparathyroidism
Ca low Corrected Ca will be low (Ca is mostly bound to albumin so if albumin is low you need a corrected Ca) Urinary Ca low Parathyroid hormone is low Mg low
hypoparathyroidism
- CT or x-ray may show dense bones
cutaneous calcifications, calcifications of basal ganglia - EKG: prolonged QT, T wave abnormalities
- Slit-lamp: early cataract formation
hypoparathyroidism
hypoparathyroidism treatment
Emergently: airway maintenance and IV calcium gluconate
Followed by: Mg if appropriate
Ca supplement
Vitamin D supplement
Close monitoring of Ca
pseudohypoparathyroidism
In pseudohypoparathyroidism you make parathyroid hormone, but the receptors don’t respond to it.
pseudohypoparathyroidism Blood work
Ca will be low
Parathyroid hormone is elevated
pseudohypoparathyroidism treatment
Cases are typically not as severe as true hypoparathyroidism
Ca supplement
Vitamin D supplement
X-ray: salt and pepper skull; demineralization
subperiosteal bone resorption especially in the fingers
cysts of the jaw
hyperparathyroidism
hyper or hypoparathyroidism can cause cataracts
hypo- do slit lamp
QT interval for hyper and hypoparathyroidism
hyper is shortened
hypo is prolonged
hyper and hypoparathyroidism
which has t wave abnormalities, bradyarrhythmias, hrt block, asystole?
hypoparathyroidism has t wave abnormalities
hyperparathryroisim has bradyarrhythmias, hrt block, and asystole
