thyroid disease Flashcards
thyroid gland
- small saddle shaped gland that wraps around the anterior portion of the trachea
- altered porduction of the thyroid hormones affects all major organ systems
- thyroid disorders are among the most common endocrine disorders and if left untreated, can result in cardiac disease and ultimately death
diagnostic tests
- thyroid antibodies (TA) thyroid
- TSH test (sensitive assay)
- T4 test
- T3 test
- T3 uptake test
- RAI uptake test (thyroid scan)
- thyroid suppression test
TA test
- serum TA is measured to determine whether a thyroid autoimmune disease is causing the client’s symptoms
- TA is elevated in Grave’s disease
TSH test
- serum TSH levels are measured and compared with T4 levels to differentiate pituitray from thyroid dysfunction.
- the best indicator of primary hyperthyroidism is suppression of TSH below 0.1 mcg/mL
- when the sensitive TSH is not suppressed the hyperthyroidis is caused by a TSH secreting pituitary tumor
T4 test
- serum T4 leves are measured to determine TH concentration to test thyroid gland function.
- T4 levels are elevated in hyperthyroidism ad acute thyroiditis
T3 test
- serum is measured by radioimmunoassay which measures bound and free forms of this hormone
- this test is effective for the diagnosis of hyperthyroidism
- T3 levels also may be elevated in thyroiditis
T3 uptake test
-T3 uptake is measured by an invitro test in which the pts blood is mixed with radioactive T3, the results are elevated in hyperthyroidism
RAI uptake scan
- measures the absorption of 131-I or 123-I by the hyroid gland
- a calculated dose of RAI is given orally or IV, an the thyroid is scanned often after 24 hrs. the distribution of radioactivity in the gland is recorded
- -RAI increase uptake is seen with Grave’s disease
- in addition the scan reveals the size and shape of the gland
thyroid suppression test
- RAI and T4 levels are measured first, the pt takes thyroid hormone for 7-10 days, after which the tests are repeated
- failure of the hormone therapy to suppress RAI and T4 indicate hyperthyroidism
The two primary lab findings used to confirm the diagnosis of hyperthyroidism are
- decreased TSH and elevated free thyroxine free T3 levels
- total T3 and T4 levels may also be assessed but they are not as definitive
serum TA test
- normal value: negative to 1:20
hyperthyroidism: increased
hypothyroidism: normal
serum TSH test (sensitive assay)
normal: 0.35-5.5 mU/mL
hyperthyroidism: decreased (in primary)
hypothyroidism: increased in primary
serum T4
normal: 4.5-11.5 mcg/dL
hyperthyroidism: increased
hypothyroidism: decreased
serum T3
normal: 80-200
hyperthyroidism: increased
hypothyroidism: decreased
T3 uptake
normal: 25-35 relative percentage
hyperthyroidism: increased
hypothyroidism: decreased
thyroid suppression
hyperthyroidism: increased RAI uptake to T4 levels
hypothyroidism: no change in RAI uptake or T4 levels
hyperthyroidism pathophysiology and etiology
- caused by excessive delivery of TH
- increases metabolic rate
- heightens sympathetic nervous systems response
hyperthyroidism etiology
autoimmune stimulation
- excess secretion of thyroid stimulating hormone (TSH)
- excessive intake of thyroid medications
risk factors (hyper)
- women (10x more likely)
- genetic factors
- family history of graves
- increased iodine intake
- age 20-40 years
hyperthyroidism clinical manifectations
- hypermetabolism
- increased appetite and weight loss
- hypermotile bowels
- heat intolerance, insomnia
- palpitations
- increased sweating
- hair changes
- palpation of thyroid gland may reveal Graves
- auscultation of thyroid gland may reveal bruits, a reflection of increased blood supply
Graves disease
- most common cause of hyperthyroidism
- autoimmune disorder (presence of MG/PA)- antibody in serum binds to TSH receptors in thyroid follicles causing hyperfunction
- enlarged thyroid land (goiter)
- manifestations of hyperthyroidism
most common cause for goiters
lack of iodine in diet
goiter can occur
in both hypo and hyperthyroidism
Graves disease clinical manifestations
- exophthalmos (abnormal protrusion of the eyeball or eyeballs)
- eye pain
- blurred vision
- diplopia (double vision)
- lacrimation (the flow of tears)
- photophobia
- increased risk of corneal dryness, irritation, infection, and ulceration
- seen in 20-40% of pts with graves
- proptosis (bilateral or unilateral) or exophthalmos= sclerosis visible above iris, the upper lids are often retracted & individual has a characteristic unblinking stare casing edema of fat deposits behind eyes & inflammation of the extraocular muscles
toxic multinodular goiter
- most common
- small, independently functioning nodules
- develops sow, usually in women 60-70s
- no opthalmopathy nor dermopathy clinical manifestations
thyroiditis
- subacute granulomatous- viral infection
- acute thyroiditis- bacterial or fungal infections
- acute disorder that may become chronic, relusting in a hypothyroid state as the repeated infections destroy the thyroid gland tissue
- symptoms are acute and include abruptonset pain localized in the thyroid radiating out the throat, ears, or jaw
- systematic fever, chills, sweats, or fatigue
thyroiditis cont.
- T4 and T3 levels initially elevated but overtime become depressed
- recovery may be compate in weeks or months
- bacterial- treat with antibiotics or surgical drainage
- NSAIDS progressing to corticosteroids if needed
- propranolol (inderol) or atenolol (tenormin) may be used to treat cardiovascular symptoms r/t hyperthyroid state
thyroid storm (thyrotoxic state)
- extreme state of hyperthyroidism
- considered life threatening emergency, death rare when treatment started early
- Rare today because of improved diagnostic tests and treatment methods
- When it does occur most commonly found in untreated graves disease patients or individuals with hyperthyroidism that experience a stressor such as infection, trauma, untreated DKA or manipulation of the thyroid gland during surgery.
- rapid increase in metabolic rate
thyroid strom clincial manifestations
- severe tachycardia
- heart failure
- shock
- hyperthermia (up to 105.3F)
- restlessness
- agitation
- seizures
- abdominal pain
- N/V/D
- delirium
- coma
- *rapid treatment is essential
thyroid storm treatment
- decrease circulating thyroid hormone levels with drug therapy
- supportive therapy- managing respiratory distress
- fever reduction
- fluid replacement
- elimination or management of the initiating stressor (s)
Excess TSH stimulation
- secondary form of hyperthyroidism- rare
- caused by overproduction of TSH by the pituitary gland
- usually stimulates the thyroid gland to produce excess of thyroid hormone
3 primary treatment options (hyperthyroidism)
- antithyroid medications
- radioactive iodine therapy (RAI therapy)
- surgery- subtotal thyroidectomy
- choice influenced by pts age, preferences, & severity of disorder
- generally treatmentof choice is RAI therapy for non-pregnant pts
hyperthyroidism drug therapy
-antithyroid drugs
-pythioruacil (PTU) and methimazole (tapazole)
-iodine= saturated solution of potassium iodine (SSKI) and lugol’s solution
-beta-adrenergic blockers (inderal and tenormin)
-anithyroid drugs-Inhibit the synthesis of thyroid hormones- improvement in 1-2 weeks Good results are usually seen within 4-8 weeks. Therapy continued for 6-15 months to allow for spontaneous remission which occurs in 20-40% of people with hyperthyroidism
Major disadvantage – noncompliance and high rate of recurrence of hyperthyroidism when drugs stopped.
-PTU 3X day Methimazole once a day.
Iodine – used with other antithyroid drugs to prepare for thyroidectomy
The administration of iodine in large doses rapidly inhibits the synthesis of T3 and T4 and blocks the release of these hormones into circulation
Beta blockers rapidly provides symptomatic relief
hyperthyroidism RAI therapy
-damages or destroys thyroid tissue
-outpatient treatment- RAI given orally
-RAI is low, no radiation precautions needed
-dryness and irritation of mouh and throat during treatment
high incidence of ost-treatment hypothyroidism in 80% of cases
-Treatment of choice
-RAI has a delayed response and the maximum effect may not be seen for 2-3 months for this reason, antithyroid drugs and Inderal are giving before and during treatment for the first 3 months until the effect of radiation become apparent
Usually very effect but there is a high incident of posttreatment hyperthyroidism that will require life –long thyroid hormone replacement therapy.
hyperthyroidism
-subtotal- leaves about 10% of thyroid gland and the remainder of gand will produce adequate TH
-total- thyroid gland removal and pts will require lifelong thyroid replacement
-Some patients with hyperthyroidism have such enlarged thyroids that pressure is put on the esophagus or trachea and causes problems with breathing or swallowing
Some patients unresponsive to antithyroid therapy or have thyroid cancer
post-op complications (hyperthyroidism surgery)
-hypothyroidism
-hemorrhage
-damage to parathyroid glands- hypocalcemia
-injury to laryngeal nerve- vocal cord paralysis
-infection
-respiratory distress
-if paralysis of both cords, spastic airway obstruction will occur resulting in immediate tracheostomy. Keep oxygen, suction equipment and tracheostomy tray at bedside immediately post-op for this type of surgery.
Respiratory distress because of excess swelling of the neck tissues.
post-op nursing care
- standard post-op care protocols
- assess pt for signs or hemorrhage or tracea compression
- place pt in semi-fowlers position and support the pts head with pillows
- avoid flexion of the neck and tension on suture line
- Tracheal compression – irregular breathing, neck swelling, frequent swallowing, sensations of fullness at the incision line, choking and blood on anterior posterior dressings
- Expect hoarseness for 3-4 days after surgery because of edema
- Control postoperative pain
- Reassure the patient that scar will fade in color and eventually look like a normal neck wrinkle. A scarf, jewelry, a high collar or other covering can effectively camouflage the scar
hyperthyroidism assessment
- health history
- physical assessment: -muscle strength, tremors
- size of thyroid gland
- eyes and vision
- cardiovascular
- vital signs
- bruit over thyroid
- integument
nursing diagnoses for hyperthyroidism
- decreased CO
- Nutritional – increased metabolism requires more calories ; Encourage six small meals per day. Snacks high in protein and complex carbohydrates
- impaired comfort
- impaired health maintenance
- risk for infection
- imbalanced nutrition-less than body requirements
- disturbed body image
planning: hyperthyroidism
- pts reports improvement
- pt will describe situations requiring contact with the provider
- pt explains how to take meds
SMART goals
S-specific M-measurable A-achievable R-relevant T-time-bound
hyperthyroidism-evalutation
- cardiac status will stabilize
- regains or maintains visual acuity
- takes in appropriate amount of calories per day
- communicates feelings about changes in body image
- explains importance of daily medications if required
