Parathyroid Disorders (Exam 3)

Question 1

How many parathyroid glands are there typically? Where are they located?

Answer 1

There are usually 4 parathyroid glands they are located posterior to each pole of the thyroid

Question 2

What hormone do the parathyroid glands release? What is the function of the hormone?

Answer 2

The parathyroid glands release parathyroid hormone (PTH) which regulates serum calcium levels.

Question 3

What are the functions of serum Ca 2+?

Answer 3

• Muscle contraction
  
  • Terminal neurons release Ca 2+ ions that bind to activator proteins which signal muscles to contract and relax
• Ca 2+ stabalizes cardiac cell membranes against depolarization in severe hyperkalemia (too much potassium)
• Essentail element of bone mineralization
• Important in blood clotting

Question 4

Bone has many uses when it comes to Ca 2+ what can is serve as?

Answer 4

A reservoir for Ca 2+

Question 5

Hypercalcemia and hypocalcemia can lead to issues with which vital organ?

Answer 5

The heart, can cause arrhythmias

Question 6

To maintain homeostatic levels of Ca 2+ the body needs how many functioning parathyroid glands?

Answer 6

1

Question 7

In the event of low Ca 2+ serum levels PTH stimulates which cells within bone to break down the bone matrix and release Ca 2+ into the blood stream?

Answer 7

Osteoclasts

Question 8

Oh snap! Blood serum levels of Ca 2+ are low, the body senses this and the parathyroid releases PTH. PTH reaches the kidneys, they respond by doing two things, what are they?

Answer 8

Reducing Ca 2+ clearance in the urine and stimulating production of 1.25dihydroxyvitaminD (Calcitriol) which stimulates the absorption of Ca 2+ in the GI tract.

Question 9

DDX for elevated calcium (Hypercalcemia)

Answer 9

• Primary hyperparathyroidism
• Familial hypocalciuric hypercalcemia
• Lithium
• Sarcoidosis
• Genetic disorders: multiple endocrine neoplasia, familial hyperparathyroidism
• Renal failure acute or chronic
• Vitamin D excess
• Granulomatous disease
• Williams syndrome
• Endrocrine disease: thyrotoxicosis, adrenal insufficiency
• Milk-Alkali syndrome
• Thiazide diuretics (She mentioned these a lot!)
• Cancers: Multiple myeloma, head, neck, lung, lymphoma

Question 10

When serum Ca 2+ levels are high osteo____ activity increases

When serum Ca 2+ levels are low osteo____ activity increases

Answer 10

1. Osteoblast activity increases in response to high levels of serum Ca 2+
2. Osteoclast activity increases in response to low levels of serum Ca 2+ (Osteoclasts break down bone and release Ca 2+ into the blood)

Question 11

Cause of 80% of hyperparathyroidism, leading to hypercalcemia

Answer 11

Benign parathyroid adenomas

Most common in women 3:1

Increased incidence after age 50

Question 12

Besides benign parathyroid adenomas what are otther causes of hypercalcemia?

Answer 12

• Renal failure
• multiple myeloma
• Head, neck, and lung cancers
• TB
• Medications
• lymphoma
• Adrenal insufficiency
• Hyperthyroidism

Question 13

The sign and symptoms of Hypercalcemia as a result of hyperparathyroidism are best summerized by the mnemonic “Stones, bones, abdominal groans, throans, and psychiatric overtones” What the hell does that mean?

Answer 13

• Stones
  
  • Kidney stones (Calcium Oxalate)
• Bones
  
  • Bone diseases of hyperparathyroidism
    
    • Osteitis fibrosa cystica (some bones become abnormally weak and deformed)
    • Osteoporosis
    • Osteomalacia (softening of bones)
    • Arthritis
• Abdominal groans
  
  • N/V/D
  • Constipation (Most common)
  • PUD (Peptic ulcer disease)
  • Pancreatitis
• Thrones
  
  • Polyuria
  • Constipation
• Psychiatric overtones (from effects on the CNS)
  
  • Depresson
  • Memory loss
  • Psychosis
  • Delerium
  • Fatigue

Question 14

Clinical features of hyperparathyroidism

Answer 14

• Thirst
• Anorexia
• Nausea
• Vomiting
• Abdominal pain
• Constipation (A big sign)
• Fatigue
• Anemia
• Wight loss
• PUD (Peptic ulcer disease)
• Pancreatitis
• HTN

Question 15

Halmark lab finding for a Dx of Hyperparathyroidism

Answer 15

Adjusted total calcium greater than 10.5 mg/dl

Question 16

Which lab test is needed to see calcium levels

Answer 16

Comprehensive metabolic panel

Question 17

Findings that can lead you to a Dx of Hyperparathyroidism

Answer 17

• Adjusted total calcium greater than 10.5 mg/dl (Hallmark finding)
• Elevated PTH
• Low phosphate level
• Imaging studies–ultrasound, CT, MRI, sestamibi scan
• EKG may show prolonged PR, shortened QT, bradycardia, heart block, and eventually asystole

Question 18

Patients who have elevated calcium levels should be screened for what?

Answer 18

Familial hypocalciuric hypercalcemia (Gene mutation that leads to elevated calcium levels)

Question 19

Treatment for hyperparathyroidism

Answer 19

• Avoid foods and medications that increase calcium levels (thiazide, diuretics, antacids, large doses of vit. A and D)
• Furosemide is a diuretic that may be used as it increases the amount of calcium lost in urine
• Increase fluids
• Exercise
• Monitor with scheduled serum calcium and albumin levels, kidney fxn test, urinary calcium excretion, and bone density
• If hypercalcemic crisis occurs treat with IV fluids and bisphosphonates
• A parathyroidectomy is indicated when symptomatic primary disorder

Question 20

How would you treat a patient in hypercalcemic crisis

Answer 20

IV fluids and bisphosphonates

Question 21

When would a parathyroidectomy be indicated

Answer 21

• In symptomatic primary hyperparathyroidism
• If serum Ca2+ is 11.5 mg/dl or greater
• Creatinine clearance less than 60 ml/minute
• Bone mineral density T score less than 2.5 at the hip, spine or wrist and/or history of previous fragility fracture
• Age less than 50

Question 22

If a parathyroidectomy is not done in a patient for whom it is indicated what needs to be done?

Answer 22

• Closely monitor serum Ca2+ and creatinine levels annually
• Bone density checks every 1-2 years

Question 23

Which is more common hyperparathyroidism or hypoparathyroidism

Answer 23

Hyperparathyroidism is more common

Question 24

Findings that indicate hypoparathyroidism

Answer 24

• Decreased PTH
• Low calcium
• Increased phosphate levels

Question 25

Common causes of hypoparathyroidism

Answer 25

* Aquired most commonly after surgical removal of thyroid or parathyroid glands * Autoimmunity * Heavy metal toxicity * Wilson's disease * Genetic disorder that causes the accumulation of copper in the body * Hemochromatosis * Accumulation of Iron * Thyroiditis * Hypomagnesemia (caused by alcoholism) * DiGeorge syndrome * congenital cause of low Ca 2+ arising from parathyroid hypoplasia * Congenital pseudohypoparathyroidism

Question 26

Clinical features of hypoparathyroidism (theres a lot of them)

Answer 26

* Abdominal cramps * Muscle cramps * Tetany * Carpopedal spasm * Paresthesias * Numbness/tingling especially around mouth or fingers * Hyperreflexia * Teeth, hair, and nail defects * Lethargy * Anxiety * Parkonsonism * Mental retardation * Blurred vision from cataracts * Personality changes * Bronchospasm * Seizures

Question 27

Contraction of eye, nose, or mouth by tapping facial never anterior to ear is what sign?

Answer 27

Chvostek sign (indicates hypocalcemia)

Question 28

A spasm produced in the hand and wrist with compression to forearm (such as applying a BP cuff).

Answer 28

Trousseau sign (indicates hypocalcemia)

Question 29

Hallmark signs to make diagnosis of hypoparathyroidism

Answer 29

* Low PTH * Low adjusted calcium * Increased phosphate * EKG may show prolonged QT, T-wave abnormalities

Question 30

As Ca2+ increases, Phosphate \_\_\_\_

Answer 30

Decreases (vice versa is true too as Ca2+ decreases phosphate increases)

Question 31

Treatments for hypoparathyroidism

Answer 31

* Directed at increasing Calcium levels (goal calcium level is 8.0-8.6 mg/dl) * Calcium and vit D supplements * Monitor adjusted serum calcium levels and urine calcium levels * Avoid furosemide and other meds that increase calcium loss * Thiazide diuretics increase calcium levels so they are safe to use * Emergency treatment with IV calcium gluconate * May use Teriparatide (recombinant PTH) off label in extreme cases to increase PTH levels.