1.
Adult Hypothyroidism (Myexedema)--develops in adulthood: Sub-clinical--most common thyroid disorder, mildly elevated serum TSH, usually asymptomatic. If the thyroid gland cannot secrete enough hormone despite excessive release of TSH, hypothyroidism occurs and a goiter may occur from the over stimulation
Clinical hypothyroidism--produces variable signs and symptoms, depending on the amount of circulating thyroid hormone. Initially, manifestations are mild and vague increasing in in incidence and severity over time
2.
Congenital Hypothyroidism (Cretinism): Occurs when a child is born with a poorly functioning or absent thyroid gland. Uncommon in the US but may occur with a lack of iodine in the mother's diet.
Newborns are lethargic, floppy, anorexic, and quiet. During infancy and early childhood symptoms include poor growth and development, feeding problems, slow pulse, subnormal temp and constipation
If untreated until child is several months old, permanent mental retardation is likely to result.
3.
Endocrine System Components: The major elements of the endocrine system are the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, pancreas, adrenal glands, ovaries, and testes.
The system participates in the regulation of essentially all body activities, including metabolism of nutrients and water, reproduction, growth and development, and adapting to changes in internal and external environments
These tissues function through hormones, substances that are synthesized and secreted into body fluids. Hormones act as chemical messengers to transmit info between body cells and organs
4.
Grave's Disease: antibody mediated autoimmune disease resulting in hyperthyroidism. Most common cause of hyperthyroidism.
Causes enlargement of the the thyroid and other symptoms such as exophthalmos (bulging eyes), heat intolerance and anxiety
5.
Hyperfunction/Hypofunction of glands: Hyperfuntion is often caused by hormone producing tumors---these are harder to treat or turn off except with surgical removal
Hypo is easier to treat because we can usually just give some synthetic hormone
6.
Hyperthyroidism: Characterized by excessive secretion of thyroid hormone and usually involves an enlarged thyroid gland that has an increased number of cells and an increased rate of secretion.
7.
Hyperthyroidism
Patient Teaching Guidelines: SE: skin rash, HA, NV, painful joints, blood dyscrasias (diseased state of the blood) , liver and bone marrow toxicity
Nursing Cons:
take at regular intervals around the clock
record weight 2x weekly and note any sudden changes
avoid foods high in iodine (soy, tofu, seafood, salt)
give in juice or milk to disguise unpleasant taste and reduce gastric irritation
give through a straw to avoid staining the teeth
may need to be taken for up to one year or longer in order to decrease thyroid hormone levels to normal
do not stop abruptly
tests of thyroid function and dosage adjustments may be needed (TSH, T3 and T4)
8.
Hypothalamus: Gland that is the link between the nervous and endocrine systems; controls secretions of almost all hormones from the pituitary gland
Growth hormone and thyroid hormone affect almost all cells
Some hormones are cyclic
growth hormone---24 hour cycle
estrogen---28 day cycle
9.
Levothyroxine (Synthroid, Levothroid) [P]: ACTION: synthetic form of T4
USE: Drug of choice for long term Tx of hypothyroidism
May take several months for peak effect
SE: S/S of Hyperthyroidism (tachycardia, nervous, tremors) watch for CP, heart palpitation, nervousness or insomnia
NURS CONS: Take every morning on an empty stomach; check pulse before taking--hold and notify MD if >100; do not stop taking abruptly can lead to life-threatening illness; brand names differ--do not switch drugs; monitor T4 and TSH; iron/antacids/cholestyramine/sucralfate decrease absorption of the drug
10.
Lugol's solution and SSKI
Strong iodine solution and saturated solution of potassium iodide: Action: Inhibit secretion of thyroid hormones
Use: iodine preparation used in short term Tx of hyperthyroidism; used to treat thyroid storm and decrease size of thyroid gland before thyroidectomy
Nurs Cons: Do not give PTU, methimazole, or radioactive iodine after giving this drug Do not give these drugs because they can cause the release of stored thyroid hormone and cause acute hyperthyroidism
11.
Myxedema coma: a severe, life-threatening hypothyroidism characterized by coma, hypothermia, cardiovascular collapse, hypoventilation, and severe metabolic disorders such as hyponatremia, hypoglycemia, and lactic acidosis. Exposure to cold, infection, trauma, respiratory disease, and CNS depressants can predispose someone to this
12.
Other Drugs for Hypothyroidism: Liothronine (Cytomel, Triostate)--synthetic T3, rapid onset and shorter duration of action; more pronounced CV side effects
Liotrix (Thyrolar)--contains levothyroxine and liothyronine
13.
Primary Hypothyroidism: Problem with the gland
Occurs when disease or destruction of thyroid gland tissue causes inadequate production of thyroid hormones
TSH is high
Common causes:
chronic (Hashimoto's) thyroiditis; an autoimmune disorder causing inflammation of the thyroid gland
radiation therapy or surgery caused by the Tx of hyperthyroidism
14.
Propranolol (Inderal): Antiadrenergcic-NOT anti-thyroid
used in thyroid storm and to control symptoms (tachycardia, palpitations, excessive sweating, tremors, and nervousness)while waiting for response to anti-thyroids
15.
Propylthiouracil (PTU) [P]: Action: Inhibits production of thyroid hormones and inhibits conversion of T4 to T3; does not interfere with release of previously produced hormone; therapeutic effects may not occur for several days or weeks--not useful in thyroid storm
SE: S/S of hypothyroidism, bood disorders, rash, HA, NVD, hepatitis
16.
Secondary Hypothyroidism: Problem with the hormone
Occurs when there is decreased thyroid stimulating hormone (TSH) from the pituitary gland or decreased thyrotropin releasing hormone (TRH) secreted from the hypothalamus
17.
Signs and Symptoms of Hyperthyroidism--
Rev Up: CV: tachycardia; increased cardiac output/blood volume/systolic BP; decreased diastolic BP; cardiac dysrhythmias, CHF
CNS: nervousness, emotional instability, restlessness, anxiety, insomnia, hyperactive reflexes
Metabolic: intolerance to heat, low grade fever, weight loss despite increased appetite
GI: increased appetite, abdominal cramps, NVD
Muscular: weakness, fatigue, muscle atrophy, tremors
Integumentary: moist, warm, flushed skin due to vasodilation and increased sweating, soft hair and nails
Reproductive: amenorrhea (no menstruation) or oligomenorrhea (light or infrequent menstruation)
Misc: dyspnea, polyuria, hoarse/rapid speech, increased susceptibility to infection, excessive perspiration, localized edema around the eyeballs, which produces characteristic eye changes, including exophthalmos
18.
Signs and Symptoms of Hypothyroidism
Slow Down: CV: Decreased: Cardiac Output, blood pressure, Heart rate--
Cardiac Enlargement, CHF, Anemia
CNS: Apathy, lethargy, emotional dullness, slow speech, hypo-active reflexes, forgetfulness/mental sluggishness, excessive drowsiness and sleeping
Metabolic Effects: Intolerance of cold, subnormal temp, Increased serum cholesterol, weight gain,
GI: Decreased appetite, constipation
Muscular: weakness, fatigue, vague aches and pains
Integumentary: dry, coarse, and thickened skin, puffy appearance of face and eyelids, dry/thinned hair, thick and hard nails
Reproductive: prolonged menstrual periods, infertility or sterility, decreased libido
Misc: increased susceptibility to infection, increased sensitivity to narcotics, barbiturates, and anesthetics due to slowed metabolism of theses drugs
19.
Sodium Iodide (Radioactive Iodine): Action: is converted to protein bound iodine by the thyroid gland for use when needed
Use: in small amounts can be used in diagnostic tests of thyroid function because the thyroid picks up the radioactive iodine; in large amounts used to treat thyroid cancer
SE: may cause cancer and chromosomal damage in children--in children should only be used for hyperthyroidism that cannot be controlled by other drugs or surgery;
may lead to hypothyroidism, necessitating lifelong hormone replacement; bone marrow depression
Contra: pregnancy and lactation
20.
T3 and T4: Hormones naturally produced by the thyroid.
T3 also called triiodothyronine contains 3 atoms of iodine
T4 also called Thyroxine contains four atoms of iodine
T3 is more potent than T4 and has a more rapid onset but shorter duration of action
Despite minor differences the two hormones produce the same physiologic effects and have the same actions and uses
21.
Thyroid: Secretes T3 andT4 (thyroxine) and Calcitonin
Production of T3 and T4 is dependent on the presence of of iodine
Probably all cells have receptors for thyroid hormones
Regulates metabolism
Stimulates protein and fat catabolism
Insulin antagonist
Necessary for growth and development (esp brain and skeletal)
Hormones have a long duration because they are bound to plasma proteins
22.
Thyroid Goiter: a visible enlargement of the thyroid gland caused by overcompensation of thyroid gland or malignancy--iodine in salt has caused the decrease in US goiters
23.
Thyroid Storm (Thyrotoxic Crisis): a rare but severe complication characterized by extreme symptoms of hyperthyroidism (everything is racing--severe tachycardia, fever, dehydration, heart failure and coma) most likely to occur in patients with hyperthyroidism that has been inadequately treated, especially when stressful situations occur (trauma, infection, surgery, emotional upset); also known as thyrotoxic crisis.
24.
Treatment for Hypothyroidism: Exogenous source of thyroid hormone--drugs that crank you up and get you going (low-fat/high fiber diet)
25.
Treatments for Hyperthyroidism: Decrease production or release of thyroid hormones; inhibit synthesis of thyroid hormone; radiation to shrink gland; removal of part/all gland
Drugs Must give for 6 months to a year
Contraindicated in pregnancy because it can lead to goiter or hypothyroidism in the newborn
Propanolol is not an anithyroid but we'll discuss its use in the use of hyperthyroidism shortly
26.
TSH: Thyroid-stimulating Hormone
TSH from the anterior pituitary gland stimulates the thyroid gland to releases T3 and T4
