Hyperparathyroidism & Hypoparathyroidism

INTRODUCTION

Disorders of the parathyroid glands, hyperparathyroidism and hypoparathyroidism, are not as common as those of the thyroid gland. Hypercalcemia and hypocalcemia (the primary results of laterations in parathyroid function).

Understanding parathyroid glands and Hyperparathyroidism

HYPERPARATHYROIDISM

DEFINITION

Hyperparathyroidism means the parathyroid glands produce too much PTH. This causes blood calcium levels to rise (hypercalcaemia) and blood phosphorus levels to fall (hypophosphataemia).

Incidence

1 in 1000 of the population.

More common in woman.

In 80% of cases of primary hyperparathyroidism caused by parathyroid adenomas are benign; 18% of cases caused by hyperplasia of the parathyroid glands: and 2% of cases are caused by parathyroid carcinoma (damjanov, 1996).

Parathyroid disease is rare below 20 years old.

ETIOLOGY

Primary hyperparathyroidism

Primary hyperparathyroidism occurs because of some problem with one or more of the four parathyroid glands:

A noncancerous growth (adenoma) on a gland is the most common cause.

Enlargement (hyperplasia) of two or more parathyroid glands accounts for most other cases.

A cancerous (malignant) tumor is a rare cause of primary hyperparathyroidism.

Primary hyperparathyroidism usually occurs randomly, but some people inherit a gene that causes the disorder.

Secondary hyperparathyroidism

· Severe calcium deficiency. Your body may not get enough calcium from your diet, often because your digestive system doesn't absorb the calcium you consume.

· Severe vitamin D deficiency. Vitamin D helps maintain appropriate levels of calcium in the blood, and it helps your digestive system absorb calcium from your food.

· Chronic kidney failure. Your kidneys convert vitamin D into a form that your body can use.

PATHOPHYSIOLOGY

Pituitary thyroid hormone hypersecretes.
Hyperplasia of pituitary thyroid glands causing the inhibition of normal cellular function.
Increase in extracellular fluid ionized calcium through direct actions of kidney and bone.
Decrease in extracellular fluid phosphate through renal action.
Leads to bone dimineralization, hypercalcemic crisis and neuromuscular disease.

SIGNS AND SYMPTOMS

When high levels of calcium do cause symptoms, they can be mild or general, including:

depression
fatigue
feeling thirsty and passing a lot of urine
feeling sick and losing your appetite
muscle weakness
constipation
tummy pain
loss of concentration
mild confusion

But, if left untreated, high blood levels of calcium can cause:

vomiting
drowsiness
dehydration
confusion
muscle spasms
bone pain or tenderness
irregular heart beat
high blood pressure

RISK FACTORS

You may be at an increased risk of primary hyperparathyroidism if you :

Are a woman who has gone through menopause
Have had prolonged, severe calcium or vitamin D deficiency
Have a rare, inherited disorder, such as multiple endocrine neoplasia, type I, which usually affects multiple glands.
Have had radiation treatment for cancer that has exposed your neck to radiation
Have taken lithium, a drug most often used to treat bipolar disorder

DIAGNOSTIC PROCEDURES

Blood tests
If the result of a blood test indicates you have elevated calcium in your blood, your doctor will likely repeat the test to confirm the results after you have not eaten for a period of time (fasted).

Bone mineral density test (bone densitometry)
The most common test to measure bone mineral density is dual energy X-ray absorptiometry, or a DXA scan. This test uses special X-ray devices to measure how many grams of calcium and other bone minerals are packed into a segment of bone.

Urine tests.
A 24-hour collection of urine can provide information on how well your kidneys function and how much calcium is excreted in your urine.

Imaging tests of kidneys.
Your doctor may order X-rays or other imaging tests of your abdomen to determine if you have kidney stones or other kidney abnormalities.

Ultrasound.

Ultrasound uses sound waves to create images of your
parathyroid glands and surrounding tissues.

Sestamibi scan.

Sestamibi is a specially designed radioactive compound that is absorbed by overactive parathyroid glands whereby a small dose of the compound is injected into your bloodstream before the imaging test is done.

COMPLICATIONS

Osteoporosis.
Kidney stones.
Cardiovascular disease.
Neonatal hyperparathyroidism.

TREATMENTS

Watchful waiting

Your doctor may recommend no treatment and regular monitoring if:

Your calcium levels are only slightly elevated
Your kidneys are functioning normally
Your bone density is normal or only slightly below normal
You have no other symptoms that may improve with treatment

Surgery

Surgery is the most common treatment for primary hyperparathyroidism and provides a cure in at least 90 percent of all cases. A surgeon will remove only those glands that are enlarged or have a tumor (adenoma).

Complications from surgery aren't common. Risks include:

Damage to nerves controlling the vocal cords
Long-term low calcium levels requiring the use of calcium and vitamin D supplements

Drugs

Calcimimetics.

A calcimimetic is a drug that mimics calcium circulating in the blood. Therefore, the drug may trick the parathyroid glands into releasing less parathyroid hormone. This drug is sold as cinacalcet (Sensipar).

Hormone replacement therapy.

For women who have gone through menopause and have signs of osteoporosis, hormone replacement therapy may help bones retain calcium. This treatment, usually a combination estrogen and progestin.

Bisphosphonates.

Bisphosphonates also prevent the loss of calcium from bones and may lessen osteoporosis caused by hyperparathyroidism.

NURSING CARE PLAN

Impaired urinary elimination related to renal involvement secondary to hypercalcemia.

Goal :

Client will resume a normal urine output as evidenced by urine production of 0.5ml/kg/hour.

Client will not develop any stones.

Interventions :

Encourage fluid intake - The client should consume at least 3000 ml of fluid per day. dehydration is dangerous in clients with hyperparathyroidism because it increases the serum calcium level and promotes the formation of renal stones.

Prevent urolithiasis - Cranberry juice or prune juice may help make the urine more acidic. Acidification helps to prevent renal stone formation because calcium is more soluble i nacidic urine than in alkaline urine.

Strain urine of stones - If a kidney stone is present, strain all urine to detect gravel and stones. Also, observe the urine for hematuria and assess the client for renal colic.

Risk of injury related to calcium imbalance.

Goal :

Express an understanding of how hypercalcemia affects his body.

Able to comply with prescribed treatments, as shown by normal serum calcium levels, to minimize organ damage.

Maintain normal body functions.

Interventions :

Monitor patient for and report signs or symptoms of calcium imbalance promptly as to prevent serious complications.

Encourage oral fluids to prevent dehydration and kidney stones and help excrete calcium.

Encourage strengthening and weight-bearing exercises to help keep calcium in bones. Provide a safe environment for ambulation ; assist the patient with ambulation if needed as a fall could result in fracture if bones are demineralized.

Encourage smoking cessation because smoking causes bone loss.

Teach patient symptoms to report and use of long-term medications, so patient can manage self-care at home.

Altered nutrition ; Less than body requirement related to anorexia and nausea.

Goal :

The client will have an adequate intake, as evidenced by absence of nausea and return to the ideal body weight.

Interventions :

A low calcium diet to correct hypercalcemia is encouraged.

Encourage the family members of patient to bring home cooked food to increase the patient appetite.

Decorate the food accordingly to attract the patient to eat.

Ensure the environment is clean and neat to increase the patient's appetite.

Monitor the intake and output chart to observe the nutritional balance.

Advise the patient to eat the medication prescribed by doctor such as antihistamines and antacids to prevent peptic ulcers.

Advise the patient to eat the antiemetics to reduce vomiting.

PROGNOSIS

Surgery will cure nearly all cases of hyperparathyroidism. If you have surgery, your doctor may want to check your calcium and PTH levels six weeks after surgery, and then on a yearly basis. You may also have a bone density test every year, as well.

HEALTH EDUCATION

Before discharge, advise the patient of possible adverse reactions to drug therapy.
Teach them and their family to identify and report signs of tetany, respiratory distress and renal dysfunction.
Emphasize the need for periodic blood tests.
If the patient did not have surgery to correct his hyperparathyroidism, warn him to avoid calcium-containing antacids and thiazide diuretics.
Encourage the patient to wear a medical identification bracelet

HYPOPARATHYROIDISM

DEFINITION

Hypoparathyroidism means the parathyroid glands produce too little PTH. This causes blood calcium levels to fall (hypocalcaemia) and blood phosphorus levels to rise (hyperphosphataemia).

INCIDENCE

In about 12% of patients undergoing surgery it lasts for only a short time.
Fewer than 3% of patients have permanent hypoparathyroidism.
More common in woman.

ETIOLOGY

The most common cause of hypoparathyroidism is accidental injury to the parathyroid glands during head and neck surgery. Other causes include:

·  Acquired hypoparathyroidism. This most common cause of hypoparathyroidism develops after accidental damage to or removal of the parathyroid glands during surgery.

·  Hereditary hypoparathyroidism. In this form, either the parathyroid glands aren't present at birth, or they don't work properly.

· Autoimmune disease. In this condition, your immune system creates antibodies against the parathyroid tissues, trying to reject them as if they were foreign bodies. In the process, the parathyroid glands stop manufacturing their hormone.

·  Extensive cancer radiation treatment of your face or neck, which can result in destruction of your parathyroid glands, or occasionally because of radioactive iodine treatment for hyperthyroidism.

· Low levels of magnesium in your blood, which can affect the function of your parathyroid glands. Normal magnesium levels are required for optimum secretion of parathyroid hormone.