Thyroid Disorders: Hyperthyroidism

Thyroid Disorders

Hyperthyroidism

Excessive thyroid hormone secretion from the thyroid gland, causing hypermetabolism and increased sympathetic nervous system activity.
Most common cause: Graves' disease, an autoimmune disorder in which antibodies are made and attach to the thyroid-stimulating hormone (TSH) receptor sites on the thyroid.
Manifestations:
- Thyrotoxicosis (excessive thyroid hormones)
- Goiter or enlargement of the thyroid gland
- Exophthalmos or abnormal protrusion of the eyes
- Pretibial myxedema or dry, waxy swelling of the front surfaces of the lower legs
- Eye problems, recent unplanned weight loss, increased appetite, and increased bowel movements
- Heat intolerance with diaphoresis
Cardiac problems:
- Increased systolic blood pressure
- Tachycardia
- Dysrhythmias
- Atrial fibrillation
Other symptoms:
- Wide mood swings
- Irritability
- Decreased attention span
- Manic behavior
Testing:
- Measurement of triiodothyronine (T3), thyroxine (T4), T3 resin uptake, and TSH
- Antibodies to the TSH receptor (thyrotropin receptor antibodies) to diagnose Graves' disease
- Thyroid scan to evaluate the position, size, and functioning of the thyroid gland
- Ultrasonography to determine size and composition of any masses or nodules
Treatment:
- Medical management: decrease the effect of thyroid hormone on cardiac function and reduce thyroid hormone secretion
- Antithyroid drugs as initial treatment
- Radioactive iodine therapy to destroy some thyroid cells
- Surgery to remove all or part of the thyroid gland (may cause complications such as hemorrhage, respiratory distress, parathyroid injury, and thyroid storm)

Hypothyroidism

Decreased metabolism from low levels of thyroid hormones
Causes:
- Damage to thyroid cells
- Inadequate iodide and tyrosine intake
- Cardiac drug amiodarone (Cordarone)
Manifestations:
- Decreased cellular energy
- Metabolites build up inside cells, forming edema (myxedema)
- Nonpitting edema, especially around the eyes, hands, and feet
- Tongue thickening and edema in the larynx, causing a husky voice
- Myxedema coma (a rare, life-threatening complication)
Cardiac and respiratory problems:
- Decreased cardiac output and perfusion to the brain and other vital organs
- Mortality rate for myxedema coma is extremely high
Other symptoms:
- Weight gain
- Depression
- Psychosocial problems
Laboratory findings:
- Decreased T3 and T4 serum levels
- High TSH levels in primary hypothyroidism
- Decreased or normal TSH levels in secondary hypothyroidism
Treatment:
- Hormone replacement therapy
- Education on hormone replacement and its side effects
- Maintenance of nutrition with a well-balanced diet and adequate fiber and fluid intake

Thyroid Dysfunction Focused Assessment

Assess cardiovascular status:
- Vital signs
- Presence or absence of peripheral edema
- Weight gain or loss
Assess cognition and mental status:
- Level of consciousness
- Orientation to time, place, and person
- Ability to accurately read a seven-word sentence
- Ability to count backward from 100 by 3s
Assess condition of skin and mucous membranes:
- Moistness of skin
- Skin temperature and color
Assess neuromuscular status:
- Reactivity of patellar and biceps reflexes
- Oral temperature
- Handgrip strength
- Steadiness of gait
- Presence or absence of fine tremors in the hand
Ask about:
- Sleep
- Diet
- Activity
- Medications
- Last bowel movement

Thyroiditis

Inflammation of the thyroid gland
Types:
- Acute or bacterial
- Subacute or viral
- Chronic (Hashimoto's disease)
Hashimoto's disease:
- Autoimmune disorder
- Triggered by bacterial or viral infection
Nursing interventions:
- Promote comfort
- Teach about hypothyroidism, drugs, and surgery

Thyroid Cancer

Four distinct types:
- Papillary
- Follicular
- Medullary
- Anaplastic
Initial manifestation: single, painless lump or nodule
Treatment: surgery (total thyroidectomy with nodal neck dissection if regional lymph nodes are involved)
Nursing interventions:
- Teach about hypothyroidism and its management
- Focus on promoting comfort and teaching about hypothyroidism, drugs, and surgery

Parathyroid Disorders

Hyperparathyroidism

Increased levels of parathyroid hormone (PTH) causing hypercalcemia and hypophosphatemia
Causes:
- Primary hyperparathyroidism
- Secondary hyperparathyroidism
Manifestations:
- Bone fractures
- Recent weight loss
- Arthritis
- Psychological distress
Laboratory tests:
- Serum PTH, calcium, and phosphate levels
- Urine cyclic adenosine monophosphate
Treatment:
- Diuretic and hydration therapies
- Drug therapy (furosemide, oral phosphates, and calcium chelators)
- Surgical management: parathyroidectomy

Hypoparathyroidism

Decreased parathyroid function
Causes:
- Iatrogenic (removal of all parathyroid tissue during total thyroidectomy)
- Idiopathic (autoimmune)
Manifestations:
- Hypocalcemia
- Hyperphosphatemia
- Tetany
- Muscle contractions
- Numbness or tingling around the mouth
Diagnostic tests:
- Electroencephalography
- Blood tests
- Computed tomography
Medical management:
- Correcting hypocalcemia
- Vitamin D deficiency
- Hypomagnesemia
Nursing management:
- Teaching about the drug regimen
- Interventions to reduce anxiety
- Education on nutrition with foods high in calcium but low in phosphorus