HYPERPARATHYROIDISM
Definition, Hyperparathyroidism is hypersecretion of parathyroid hormone. It is most common among women older than age 50.
Causes
1. Primary hyperparathyroidism
a. Single parathyroid adenoma is the most common cause ((approximately 80% of cases)]
b. Parathyroid hyperplasia accounts for approximately 20% of cases.
c. Parathyroid carcinoma accounts for < 1% of cases.
2. Secondary hyperparathyroidism
a. Primarily the result of renal failure.
Clinical Manifestations
1. Decalcification of bones.
a. Skeletal pain, backache, pain or weight bearing, pathologic fractures, deformities, formation of bony cysts
b. Formation of bone tumors [Overgrowth of osteoclasts).
c. Formation of Calcium containing kidney stones.
2. Depression of neuromuscular function
a. The patient may trip, drop objects, show general fatigue, lose memory for recent events, experience emotional instability, have changes in level of consciousness, with stupor and coma.
b. Cardiac arrhythmias, hypertension, cardiac standstill.
Diagnostic Evaluation
1. Elevated Serum calcium levels
2. PTH levels are increased.
3. Serum alkaline phosphatase levels. elevated and serum phosphorus levels decreased
4 Skeletal changes - [bone changes] detected on x-ray films.
5. computed tomography (CT) [will] disclose parathyroid tumors [more readily than x-ray].
6. Exclusion of other causes of hypercalcemia malignancy (usually bone or breast), vitamin D excess, multiple myeloma, sarcoidosis, milk-alkali syndrome, drugs such as thiazides, Cushing's disease, hyperthyroidism,
Medical Management
Treatment of hypercalcemia
1. Hydration (IV saline) and diuretics furosemide (Lasix) and ethacrynic acid (Edecrin) - increases urinary excretion of calcium in patients not in renal failure.
2. Oral phosphate used as an anti-hypercalcaemic agent.
3. Plicamycin (Mithramycin), calcitonin (Cibacalcin), or etidronate disodium (Didronel)-treat hypercalcemia by inhibiting bone resorption.
4. Foods high in calcium and phosphorus. E.g. Milk and milk products are limited.
5. Drugs that might cause hypercalcemia (Thiazides, Vitamin D) are discontinued.
6. Dialysis may be necessary in patients with resistant hypercalcemia or those with renal failure.
7. [Digitalis is reduced because patient with hypercalcemia is more sensitive to toxic effects of this drug.]
8. Monitor serum calcium, BUN, potassium and magnesium levels daily.
Treatment of Primary Hyperparathyroidism
Surgical removal of abnormal parathyroid tissue.
Complications
1. Formation of renal stones, calcification of kidney parenchyma, renal shutdown.
2. Ulceration of upper GIT [leading to haemorrhage and perforation]
3. Demineralization of bones, cysts and fibrosis of marrow leads to fractures, especially of vertebral bodies and ribs.
4. Hypoparathyroidism after surgery.
Nursing Interventions
1. Monitor fluid I/O.
2. Provide adequate hydration [administer water, glucose and e orally or IV as prescribed].
3. Prevent or promptly treat dehydration by reporting vomiting or other sources of fluid loss promptly.
4. Help patient understand why and how to avoid dietary sources of calcium - dairy products, broccoli, calcium-containing antacids.
5. Strain all urine to observe for stones.
6. Increase fluid intake to 3,000 ml/day to maintain hydration and prevent precipitation of calcium and formation of stones.
7. Observe for signs of UTI, haematuria and renal colic. Assess renal function through serum creatinine and BUN' levels.
8 Assist patient in activities if bone pain is severe or if the patient experiences musculoskeletal weakness.
9. Protect the patient from falls or injury.
10. Encourage patient to participate in mild exercise gradually as symptoms subside
11. Encourage patient to verbalize fears and feelings and prepare for surgery (as for thyroidectomy).
12. Monitor ECG to detect changes 2 to hypercalcemia (During moderate elevations of serum calcium, QT interval is shortened, with extreme hypercalcemia, widening of the T wave is seen).
13. Monitor serum calcium level and evaluate for signs and symptoms of hypocalcaemia and onset of tetany, Watch for development of tetany caused by removal or disturbance of parathyroid glands.
a Tingling of toes and fingers and around the mouth; apprehension
b. Positive Chvostek's sign-tapping of the cheek over the facial n. causes a twitch of the lip or facial muscles.
c. Positive Trousseau's sign circulation in the arm with BP cuff. carpopedal spasm induced by occluding
14. Instruct the patient about calcium-reducing medications.
a. Calcitonin (Cibacalcin) - given S/C-teach proper technique.
b. Etidronate disodium. (Didronel) Calcium rich foods should be avoided within 2 hrs. of dose, therapeutic response may take 1-3 months.
c. Plicamycin (Mithramycin) anti neoplastic drug that may cause nausea, vomiting and stomatitis, inspect oral mucosa regularly.
