Ignatavicius: Medical-Surgical Nursing, 6th Edition

Chapter 66: Care of Patients with Problems of the Thyroid and Parathyroid Glands

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Chapter 66 reviews common disorders of the thyroid and parathyroid glands. Hormones from the thyroid and parathyroid glands affect overall metabolism, electrolyte

balance, and excitable membrane activity. Hyperthyroidism is excessive thyroid hormone secretion from the thyroid gland, where

normal feedback control over thyroid hormone secretion fails. Thyroid hormones affect metabolism in all body organs and systems, thus, excesses produce

many different manifestations called thyrotoxicosis. Excessive thyroid hormones cause hypermetabolism and increased sympathetic nervous

system activity. The most common cause of hyperthyroidism is Graves’ disease, also called toxic diffuse

goiter. Patients with Graves’ disease usually have thyrotoxicosis, a goiter or enlargement of the

thyroid gland, exophthalmos or abnormal protrusion of the eyes, and pretibial myxedema or dry, waxy swelling of the front surfaces of the lower legs.

Graves’ disease is an autoimmune disorder in which antibodies are made and attach to the thyroid stimulating hormone receptor sites on the thyroid.

The patient may report eye problems, a recent unplanned weight loss, an increased appetite, and an increase in the number of bowel movements per day.

A hallmark of hyperthyroidism is heat intolerance with diaphoresis even when environmental temperatures are comfortable for others.

Observe the size and symmetry of the thyroid gland and palpate the thyroid gland to assess the presence of a mass or general enlargement.

Cardiac problems of hyperthyroidism include increased systolic blood pressure, tachycardia, dysrhythmias, and atrial fibrillation, which may be apparent on electrocardiography.

The patient with hyperthyroidism often has wide mood swings, irritability, decreased attention span, and manic behavior.

Testing for hyperthyroidism includes measurement of triiodothyronine (T3), thyroxine (T4), T3 resin uptake (T3RU), and thyroid-stimulating hormone (TSH).

Thyroid scan evaluates the position, size, and functioning of the thyroid gland. Ultrasonography can determine size and the composition of any masses or nodules. The goals of medical management are to decrease the effect of thyroid hormone on cardiac

function and to reduce thyroid hormone secretion. Priorities for nursing care focus on monitoring for complications, reducing stimulation,

promoting comfort, and teaching about therapeutic drugs and procedures. Drug therapy with antithyroid drugs is the initial treatment of hyperthyroidism. Radioactive iodine therapy may be used to destroy some of the cells that produce thyroid

hormone but is not used in pregnant women. Surgery to remove all or part of the thyroid gland may be needed when a large goiter causes

tracheal or esophageal compression or with poor response to drugs. Thyroid surgery can cause hemorrhage, respiratory distress, parathyroid injury resulting in

hypocalcemia and tetany, damage to laryngeal nerves, and thyroid storm. Thyroid storm or thyroid crisis occurs when the disease is untreated or poorly controlled or is

triggered by stressors such as trauma, infection, diabetic ketoacidosis, and pregnancy. This is an extreme state of hyperthyroidism in which manifestations are more severe and life

Copyright © 2010, 2006, 2002 by Saunders, an imprint of Elsevier Inc.

threatening and is most common in patients who have Graves’ disease. The patient at risk for thyroid storm should remain in a cool, dark, and quiet environment. The manifestations of hypothyroidism are the result of decreased metabolism from low

levels of thyroid hormones. Sometimes the thyroid cells themselves are damaged and no longer function normally or the

individual does not ingest enough iodide and tyrosine. Myxedema coma is a rare, serious complication of untreated or poorly treated

hypothyroidism. Decreased metabolism causes the heart muscle to become flabby and dilated, resulting in

decreased cardiac output and perfusion to the brain and other vital organs. The mortality rate for myxedema coma is extremely high and this condition is considered a

life-threatening emergency. Observe the patient’s overall appearance for coarse features, edema around the eyes and face,

a blank expression, a thick tongue, and slow movement. Cardiac and respiratory functions are decreased and body temperature is often low. Weight gain is very common, even when the person is ingesting an appropriate amount of

calories for size, age, and gender. Triiodothyronine (T3) and thyroxine (T4) serum levels are decreased. The patient with hypothyroidism requires lifelong thyroid hormone replacement. The patient with more severe symptoms of hypothyroidism is started on the lowest dose of

thyroid hormone replacement, especially with known cardiac problems. Thyroiditis is an inflammation of the thyroid gland. There are three types: acute or bacterial, subacute or viral, and chronic. Chronic thyroiditis or Hashimoto’s disease is the most common type. Hashimoto’s disease is an autoimmune disorder that is usually triggered by a bacterial or viral

infection. The four distinct types of thyroid cancer are papillary, follicular, medullary, and anaplastic,

with the initial manifestation of a single, painless lump or nodule. Surgery is the treatment of choice for papillary, follicular, and medullary carcinomas. A total thyroidectomy is usually performed with a nodal neck dissection if regional lymph

nodes are involved. Usually the patient is hypothyroid after treatment for thyroid cancer. Nursing interventions then focus on teaching the patient about hypothyroidism and its

management. The parathyroid glands maintain calcium and phosphate balance. In hyperparathyroidism, increased levels of parathyroid hormone act directly on the kidney,

causing increased kidney reabsorption of calcium and increased phosphate excretion. These processes cause hypercalcemia and hypophosphatemia. Ask about bone fractures, recent weight loss, arthritis, or psychological distress. Determine whether the patient has received radiation treatment to the head or neck. High levels of PTH cause kidney stones and deposits of calcium in the soft tissue of the

kidney. Bone lesions are due to an increased rate of bone destruction and may result in pathologic

fractures, bone cysts, and osteoporosis. Gastrointestinal manifestations are common when serum calcium levels are high. Serum PTH, calcium, and phosphate levels and urine cyclic adenosine monophosphate are

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laboratory tests used to detect hyperparathyroidism. Diuretic and hydration therapies are used most often for reducing serum calcium levels in

patients who are not candidates for surgery. The priority nursing interventions focus on monitoring and prevention of injury. Drug therapy is used when hydration and furosemide cannot reduce hypercalcemia, or if it is

necessary to discontinue IV fluids. Other drugs, such as oral phosphates and calcium chelators, can help to reduce the

manifestations of hyperparathyroidism, especially those related to hypercalcemia. Surgical management of hyperparathyroidism is a parathyroidectomy. When hyperparathyroidism is due to hyperplasia, three glands plus half of the fourth gland are

usually removed. If all four glands are removed, a small portion of a gland may be implanted in the forearm,

where it produces PTH and maintains calcium homeostasis. Hypoparathyroidism is a rare endocrine disorder in which parathyroid function is decreased. Whether the problem is a lack of PTH secretion or an ineffectiveness of PTH on tissues, the

result is the same: hypocalcemia. Iatrogenic hypoparathyroidism, the most common form, is caused by the removal of all

parathyroid tissue during total thyroidectomy or by deliberate surgical removal of the parathyroid glands.

Idiopathic hypoparathyroidism can occur spontaneously and may be autoimmune. The physical assessment may show excessive or inappropriate muscle contractions that cause

finger, hand, and elbow flexion, signaling an impending attack of tetany. Diagnostic tests for hypoparathyroidism include electroencephalography, blood tests, and

computed tomography. Medical management of hypoparathyroidism focuses on correcting hypocalcemia, vitamin D

deficiency, and hypomagnesemia. Nursing management includes teaching about the drug regimen and interventions to reduce

anxiety. Teach the patient to eat foods high in calcium but low in phosphorus. Collaborate with the nutritionist to teach patients about diets that are restricted in calcium or

phosphate and include the person who prepares the patient’s meals. Stress that therapy for hypocalcemia is lifelong.

REVIEWManifestations of heat intolerance, increased bowel movement, weight loss, and tachycardia reflect possible:

A. HypoparathyroidismB. HypothyroidismC. HyperthyroidismD. Hyperparathyroidism

Copyright © 2010, 2006, 2002 by Saunders, an imprint of Elsevier Inc.

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