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