Hypothyroidism Flashcards Preview

Med-Surg > Hypothyroidism > Flashcards

Flashcards in Hypothyroidism Deck (9)
Loading flashcards...
1

What is hypothyroidism?

A deficiency of thyroid hormone that causes a general slowing of the metabolic rate
-4% of US population has mild hypothyroidism, w/ 0.3% having more severe disease
-more common in women

2

Patho

-Primary: related to destruction of thyroid tissue or defective hormone synthesis
-Secondary: Related to pituitary disease with decreased thyroid-stimulating hormone (TSH) secretion or hypothalamic dysfunction w/decreased thyrotropin-releasing hormone (TRH) secretion
-can be transient, related to thyroiditis or discontinuing thyroid hormone therapy

3

Causes of hypothyroidism?

-Iodine deficiency most common
-in US common cause of primary is atrophy (wasting away) of thyroid gland. This is the end result of Hashimoto's thyroiditis or Graves disease
-autoimmune diseases destroy thyroid gland

4

May also develop as a result of treatment of?

Hyperthyroidism, specifically thyroidectomy or radioactive iodine (RAI) therapy.
- Drugs such as amiodarone (Cordarone), which contains iodine or lithium that block hormone production, can cause hypothyroidism

5

Hypothyroidism that develops in infancy (cretinism) is caused by?

Thyroid hormone deficiences during fetal or early neonatal life

6

Clinical manifestations of hypothyroidism

-vary depending on severity & duration of thyroid deficiency as well as patients age at onset of deficiency
-has systemic affects characterized by a slowing of body processes
-fatigue
-lethargic
-personality and mental changes including impaired memory, slowed speech, decreased initiative and somnolence
-many appear depressed
-weight gain
-decreased CO, contractility, and coronary atherosclerosis
-anemia
-increased serum cholesterol & triglyceride levels and the accumulation of mucopolysaccharides in the intima of small blood vessels can result in coronary atherosclerosis
-decreased GI motility & achlorhydria (absence or decreased secretion of hydrochloric acid
-constipation may progress to obstipation
-older adult: fatigue, cold and dry skin, hair loss, constipation, hoarseness, and cold intolerance
-myxedema: puffiness, facial and periorbital edema, and masklike effect
-altered self image

7

Hypothyroidism complications

The mental sluggishness, drowsiness, and lethargy may progress gradually or suddenly to a notable impairment of consciousness or coma. This situation, termed myxedema coma, consititutes a medical emergency
-myxedema coma can be precipitated by infection, drugs (opioids, tranquilizers, and barbiturates), exposure to cold, and trauma. characterized by subnormal temperature, hypotension, and hypoventilation
-For the pt to survive, vital functions must be supported and IV thyroid hormone replacement administered

8

Hypothyroidism diagnostic studies

- Serum TSH and free thyroxine (FT4) are most reliable indicators of thyroid function
- Serum TSH levels help determine the cause. If high, the defect is in the thyroid; if low, it is in the pituitary or hypothalamus
- Presence of thyroid antibodies suggests an autoimmune origin or the hypothyroidism
- Elevated cholesterol and triglycerides, anemia, and increased creatine kinase can occur

9

Hypothyroidism interprofessional care

-goal is restoration of the euthyroid state as safely & rapidly as possible w/hormone therapy
-low calorie diet indicated to promote weight loss or prevent weight gain
-Levothyroxine (Synthroid) drug of choice. In young pt the maintenance replacement dosage is adjusted according to the pt's response and lab findings.
-initial doses are low to avoid increases in resting HR and BP
-pt w/compromised cardiac status, careful monitoring is needed when starting and adjusting the dosage because the usual dose may increase myocardial oxygen demand, causing angina & cardiac dysrhythmias
-Levothyroxine has a peak action of 1-3 weeks. In the pt w/out side effects the dose is increased at 4-6 week intervals
-Liotrix: synthetic mix of levothyroxine (T4) and liothyronine (T3) in a 4:1 combination. Fast onset of action and a peak of 2-3 days, can be used in acutely ill pt's