Parathyroid Disorders: Understanding Primary, Secondary, and Tertiary Hyperparathyroidism, Exams of Nursing

Download Parathyroid Disorders: Understanding Primary, Secondary, and Tertiary Hyperparathyroidism and more Exams Nursing in PDF only on Docsity! Parathyroid disorders (PEARLS) (Smarty PANCE) 100% VERIFIED ANSWERS 2024/2025 Where is parathyroid hormone produced? Parathyroid hormone comes from the parathyroid glands which are buried within the thyroid gland What is the main job of the parathyroid glands? Their main job is to keep blood calcium levels stable How does parathyroid hormone affect calcium and phosphate levels in the blood? Parathyroid hormone increases blood calcium and decreases phosphate level. How are changes in the body’s levels of extracellular calcium detected? Changes in the body's levels of extracellular calcium are detected by a surface receptor in parathyroid cells that's called the calcium-sensing receptor. These changes affect the amount of parathyroid hormone that's released by the parathyroid gland. How does parathyroid hormone function in the body? Parathyroid hormone gets the bones to release calcium, it gets the kidneys to reabsorb more calcium so it's not lost in the urine, and it synthesizes calcitriol, which is also known as 1,25-dihydroxycholecalciferol, or active vitamin D. Active vitamin D then goes on to cause the gastrointestinal tract to increase calcium absorption. Altogether, these effects help to keep the extracellular levels of calcium within a narrow range that's between 8.5 to 10 mg/dl. Define primary HPTH In primary hyperparathyroidism, the parathyroid gland is responsible for the problem, because it makes parathyroid hormone independently of the calcium level. Excess parathyroid hormone stimulates osteoclasts to break down bone and makes the kidneys hold on to calcium and get rid of phosphate - resulting in hypercalcemia and hypophosphatemia. It's marked by elevated calcium and low phosphorus. Usually caused by a PTH secreting parathyroid ADENOMA What are the etiologies of primary HPTH and percentages? The most most common cause of primary hyperparathyroidism is parathyroid adenoma which is a benign tumor ( 85%), Hyperplasia (10%), Carcinoma ( 1%) What percentage of adenomas are not single but found in more than one gland? 5% of adenomas are found in more than one gland Define secondary HPTH In secondary hyperparathyroidism, the parathyroid gland is normal but ↑ PTH by a physiologic response to hypocalcemia or vitamin D deficiency Causes of secondary HPTH? Secondary hyperparathyroidism is caused by chronic hypocalcemia which cause the parathyroid gland to makes excess parathyroid hormone. Causes include calcium wasting caused by renal failure or decreased GI calcium absorption, rickets or osteomalacia; calcium levels are usually low. Chronic kidney disease is the most common cause of secondary hyperparathyroidism. Define tertiary HPTH Tertiary hyperparathyroidism is a situation where individuals who have had secondary hyperparathyroidism for many years develop primary hyperparathyroidism. In tertiary hyperparathyroidism parts of the parathyroid gland start making parathyroid hormone independently of blood calcium levels - resulting in hypercalcemia. How can you remember the symptoms of primary hyperparathyroidism? Surgical operation Ultrasound Sestamibi scan 201 TI (technetium)-thallium subtraction scan CT/MRI A-gram (rare) Venous sampling for PTH (rare) What is the definitive treatment of primary and tertiary hyperparathyroidism? Surgery! Treatment of primary and tertiary hyperparathyroidism is done by removing the abnormal parathyroid glands with surgery. Calcimimetics, drugs that imitate the action of calcium by attaching to the calcium-sensing receptors on parathyroid cells, are used if surgery is not possible What is the initial medical treatment of hypercalcemia in primary HPTH? The initial medical treatment of hypercalcemia in primary HPTH includes IV fluids and furosemide—NOT thiazide diuretics Treatment of secondary hyperparathyroidism? Sometimes with secondary hyperparathyroidism, surgery is used, but normally treatment is aimed at managing the hyperphosphatemia with phosphate binders and to increase the levels of vitamin D, using supplements and calcitriol analogs. What is the incidence of primary HPTH in the United States? The incidence of primary HPTH in the United States is 1/1,000-1/4,000 What are the risk factors for primary HPTH? The risk factors for primary HPTH include family history, MEN-I and MEN-IIa, irradiation What is the "33 to 1" rule? Most patients with primary hyperparathyroidism have a ratio of serum (Cl-) to phosphate > 33 What plain x-ray findings are classic for HPTH? Subperiosteal bone resorption (usually in hand digits) are said to be "pathognomonic" for HPTH! What is the differential diagnosis of hypercalcemia? What is the differential diagnosis of hypercalcemia can be remembered by "CHIMPANZEES": ● Calcium overdose ● Hyperparathyroidism (1 /2 /3 ) ● Hyperthyroidism, Hypocalciuric Hypercalcemia (familial) ● Immobility/Iatrogenic (thiazide diuretics) ● Metastasis/Milk alkali syndrome (rare) ● Paget's disease (bone) ● Addison's disease/acromegaly ● Neoplasm (colon, lung, breast, prostate, multiple myeloma) ● Zollinger-Ellison syndrome ● Excessive vitamin D ● Excessive vitamin A ● Sarcoid Although most recommend surgery for asymptomatic primary hyperparathyroidism when is it considered mandatory? R - Renal insufficiency (CR ↓ by 30%) O - Osteoporosis (T score < -2.5) A - Age < 50 C - Calcium 1 mg/dl above upper limit of normal H - Hypercalciuria (400 mg/day Ca 2 excretion) Why place 30 to 40 mg of sliced parathyroid gland in the forearm after surgery? To retain parathyroid function; if HPTH recurs, remove some of the parathyroid gland from the easily accessible forearm What carcinomas are commonly associated with hypercalcemia? Breast cancer metastases, prostate cancer, kidney cancer, lung cancer, pancreatic cancer, multiple myeloma What is the most likely diagnosis if a patient has a PALPABLE neck mass, hypercalcemia, and elevated PTH? Parathyroid carcinoma (vast majority of other causes of primary HPTH have nonpalpable parathyroids) One more time - what are the labs in primary hyperparathyroidism? Primary hyperparathyroidism will have high calcium and low phosphate. One more time - what are the labs in secondary hyperparathyroidism in chronic renal disease? Secondary hyperparathyroidism in chronic renal disease will have low calcium, elevated phosphate, and low vitamin D What is hypoparathyroidism? Hypoparathyroidism refers to a condition where there is an underproduction of parathyroid hormone (PTH) How are calcium levels affected in hypoparathyroidism? Calcium levels are decrease in hypoparathyroidism. Calcium is low because the gland cannot secrete PTH (hence a low PTH) and PTH is responsible for the reabsorption of calcium from the bones, kidneys and GI tract. Because you can't reabsorb Calcium, your calcium will be low. What is the most common cause of hypoparathyroidism? The most common cause of hypoparathyroidism is surgical removal of the parathyroid glands after thyroid surgery (thyroidectomy)