week 8- hyper and hypo thyroidism

Question 1

The thyroid makes thyroid hormone (T3 & T4)

Answer 1

Controls metabolism
Balances calcium and phosphorus
Regulated by the Hypothalmic-Pituitary-Thyroid negative feedback loop
Need dietary intake of protein & iodine to produce TH
Thyroid hormones affect all body cells, specifically:
—Effects on growth, metabolic rate and specific body mechanisms
—T3 & T4 increase metabolism=increased O2 consumption and heat production in all tissues (Iggy, 2010)

Question 2

conversion of T’S

Answer 2

T4 converts to T3 in the cell

Conversion is impaired by: stress, starvation, dyes, beta blockers, amiodarone, corticosteroids, and PTU

Question 3

Functions of TH

Answer 3

Fetal development
Control metabolic rate
Growth hormone and gonadotropins (pituitary)
Regulates protein, carb and fat metabolism
Chronotropic and inotropic cardiac effects (rate and force of contraction)
Increases RBC production
Affects resp rate and drive
Increases bone formation and decreases bone resorption of calcium (through calcitonin release)
Acts as insulin antagonist

Question 4

Thyroxine (T4)

Answer 4

-influences metabolic rate, regulates lipid & carbohydrate metabolism

Question 5

Triiodothyronine (T3)-

Answer 5

help regulate growth development, metabolism and controls heat regulation (thermoregulating center)

Question 6

Calcitonin-

Answer 6

responds to hypercalcium, lowers plasma calcium and phosphate levels, inhibits reabsorption of calcium into bones

Responsible for maintaining adequate levels of calcium in the extracellular fluid

Question 7

Thyroid gland communicates with parathyroid gland that lies above and behind it.

Answer 7

Iodine and tyrosine(amino acid) is essential for proper functioning of thyroid glands which generally is acquired in sufficient amounts from our diet.
T3 &T4 are stored with thyrogloblin (a protein that contains tyrosine and amino acid) in the follicles in the thyroid gland called colloids
When thyroid gland is signaled it will release T3 & T4 into the circulation system. Low blood level will trigger TSH (thyroid stimulating hormone) known as thyrotropin.

Question 8

Negative Feedback Loop

Answer 8

Hypothalamus produces and secretes thyrotropin-releasing
hormone (TRH)
—->
TRH stimulates the anterior pituitary to secrete thyroid stimulating hormone (TSH)
—>
TSH stimulates the thyroid gland to increase production of
T3 (triiodothyronine) and T4 (thyroxine)

Question 9

neg feedback looop

Answer 9

If the thyroid hormone (T3 & T4) levels get too high, the hypothalamus decreases secretion of TRH and the pituitary decreases secretion of TSH

If the thyroid hormone (T3 & T4) levels get too low, the hypothalamus increases secretion of TRH and the pituitary increases secretion of TSH
So….
Hyperthyroid = HIGH T3 & T4 and LOW TSH
Hypothyroid=LOW T3 & T4 and HIGH TSH

Question 10

Thyroid Disease

Answer 10

 Hypothyroidism more common that hyperthyroidism
 Women affected > men
 Symptoms of thyroid disease extremely variable
 New onset or a change in symptoms important
 May develop quickly or slowly
 Only blood tests confirm diagnosis
 Iodine deficiency in undeveloped countries most common cause of hypothyroidism = goiter (enlarged thyroid gland)
 Iodine added to salt in many countries

Question 11

Thyroid Disease: Causes

Answer 11

-Primary Causes
 Autoimmune disorders
 Graves’ Disease (hyperthyroidism)
 Hashimoto’s Thyroiditis (hypothyroidism)
• Secondary Causes
 Pituitary tumours, surgery, irradiation, medications
 Plummer’s disease (toxic nodular disease “hot nodule”)
 Multinodular disease

Question 12

Graves’ disease affects mostly women and between age

Answer 12

20-40.

Question 13

Hyperthyroid

s&s

Answer 13

	Low energy
	Fatigue-trouble awakening in am, need more sleep, falls asleep during the day
	Feeling cold when others feel warm
	Less sweating
	Dry, itchy skin
	Dry, coarse, brittle hair
	Increased hair loss (thinner)
	Loss of outer third of eyebrow
	Loss of appetite
	Mild weight gain (5-15 lbs), difficulty losing weight ** does not cause obesity
	New or worsening memory problems and slowed thinking
	New snoring
	More frequent muscle cramps and joint aches
	New feeling of pins and needles in hands and feet (parasthesia)
	New constipation 
	New puffiness around the face (especially eyes), hands, feet and ankles
	Carpal tunnel
	Heavier and/or more frequent periods, worse cramps, worse premenstrual symptoms
	Feeling irritable
	New depression
	New hoarse voice
	New hearing loss
	Goiter (enlarged thyroid gland)-most common with Hashimoto’s thyroiditiis
	Shrinking thyroid
	Decreased HR-decreased blood flow and O2 delivery to tissues 
	Slight increase in BP 
	Higher cholesterol levels 
	Slow reflexes
	Heat intolerance*
	Diaphoresis/smooth moist skin
	Hair loss
	Weight loss with increased appetite
	Nervousness & tremors
	Palpitations, tachycardia, Atrial fib
	Insomnia
	Goiter
	Menstrual irregularities (-)
	Hypertension
	Frequent bowel movements*

Question 14

Hypothyroid

s&S

Answer 14

	Cold intolerance
	Dry coarse skin
	Hair loss
	Weight gain with poor appetite
	Fatigue/lethargy
	Bradycardia
	Hypersomnia
	Goiter
	Menstrual irregularities (+)
	Slow thinking/memory
	Constipation*
	Tachycardia/palpitations
	Chest pain
	Increased SBP
	Dysrhythmias
	Muscle weakness/wasting
	Blurred or double vision
	Eye fatigue
	Corneal ulcers or infections
	Increased tears/redness/photophobia
	Eyelid retraction/eyelid lag**Graves’ disease only
	Globe lag** Wide-eyed startled look
	Hyperactive tendon reflexes
Low grade fever

Question 15

Assessment

Answer 15

 When patient reports general symptoms of fatigue or unplanned weight change and depression or anxiety, be sure to ask about other S &S related to thyroid disorders that they may not automatically mention
 Nutrition, elimination, sleep-rest pattern, sexuality-reproductive & activity-exercise assessments (Iggy, 2010)
 Head-to-toe assessment-affects all body systems
 Inspect and palpate thyroid gland (See Jarvisnot usually part of a routine nursing assessment)
 Review diagnostic test results
 Discuss life impact (ie: work, activity, relationships)
 When patient reports general symptoms of fatigue or unplanned weight change and depression or anxiety, be sure to ask about other S &S related to thyroid disorders that they may not automatically mention
 Nutrition, elimination, sleep-rest pattern, sexuality-reproductive & activity-exercise assessments (Iggy, 2010)
 Head-to-toe assessment-affects all body systems
 Inspect and palpate thyroid gland (See Jarvisnot usually part of a routine nursing assessment)
 Review diagnostic test results
 Discuss life impact (ie: work, activity, relationships)

Question 16

Diagnostic Testing

Answer 16

• TSH is the most sensitive test of thyroid function
o Decreased TSH = hyperthyroidism
o Increased TSH = hypothyroidism
• T4 testing may help differentiate sub-clinical (mild)disease
• Imaging tests-ultrasound, Radioactive Iodine Scan
• Fine needle biopsy
• CBC, lipid profile, metabolic profile
• ECG

Ultrasound: info about solid vs cystic nodules, info about benign vs malignant tumours (looks at border edges, vascularity, presence of microcalcifications),
RAI Scan: identify whether nodule is “hot” (more likely benign) or “cold” (more likely malignant)

Pts with hypothyroidism may also have iron deficiency anemia, dyslipidemia, hyponatremia, and decrease GFR

Question 17

Toxic Nodular Disease “hot nodule”

Answer 17

• This scan shows a solitary “hot” nodule located in the left lobe
• This single nodule is comprised of thyroid cells which have lost their regulatory mechanism that dictates how much hormone to produce
• Without this regulatory control, the cells in this nodule produce thyroid hormone at a dramatically increased rate causing symptoms of hyperthyroidism
• Some nodules are “cold” since they
o don’t produce any hormone at all

Question 18

Risk Factors: Hypothyroidism

Answer 18

Family history
Personal history of thyroid disease
Women over 50 & the elderly
History of autoimmune diseases
6 weeks to 6 months postpartum or during menopause
White or Asian

One of the most common thyroid disorders
Affects people worldwide regardless of age, sex, race, wealth, education
Almost half of people with hypothyroidism don’t know it

Question 19

Treatment: Hypothyroidism

Answer 19

• Synthetic thyroid hormone replacement for life
• Levothyroxine once daily
• Long half-life (7 days)
• Dose slowly increased until thyroid hormone levels normal
• Goal of thyroid replacement therapy is to keep TSH in the low normal range (euthyroid)
• Dosage based on age, weight, and cardiac status
• **use caution in patients with cardiac disease
• *Bowel movement regularity an important guide to therapeutic effect
• Full effect expected in 4-6 weeks

Question 20

Patient Teaching: Hypothyroidism Treatment

Answer 20

Levothyroxine absorption affected by:
• Dietary fibre
• Antacids
• Iron
• Calcium
• Take with full glass of water
• Best one hour before breakfast
• Same time daily
• Consult HCP before taking other OTC medications
• **over-replacement is biggest problem (know hyper S & S!)
• Do not stop taking abruptly – causes rebound effects
• Monitor for CV disease and symptoms
• Use cautiously with Coumadin*report bruising or bleeding (increases the effects of Coumadin)

Question 21

Myxedema Coma

Answer 21

Sudden drop in thyroid hormone
Due to undiagnosed or untreated hypothyroidism or incorrect treatment (inadequate dose, pt stops taking his/her medications suddenly)
Or precipitated by: trauma, infection, or surgery
Rare but often deadly
Risk Factors: new-onset HF, recent stroke, use of amiodarone, lithium, phenothiazines, tranquilizers

Question 22

Myxedema Coma: S & S

Answer 22

Exaggerated hypothyroidism S & S
	Weakness
	Confusion (untreated, leads to coma)
	Hypothermia (severe)
	Edema
	Breathing difficulties
	Most common in older women in winter months
	**mental status  and respiratory assessment a priority

Question 23

Myxedema Coma: Treatment

Answer 23

Administer oxygen
Ventilator support
Levothyroxine IV initially

Question 24

Nursing Diagnoses

Answer 24

Ineffective breathing pattern related to decreased energy, weight gain and fatigue
Decreased cardiac output related to altered heart rate and rhythm
Disturbed thought processes related to impaired brain metabolism and edema

Question 25

Treatment: Hyperthyroidism

Answer 25

 More complicated than hypothyroidism  Managed by an endocrinologist ``` Treatment Options:  Radioactive Iodine therapy (RAI) (treatment of choice)  Antithyroid medications  Iodine products  Surgery  Beta-blockers ```

Question 26

Radioactive Iodine Therapy

Answer 26

 Oral doses are absorbed quickly by the stomach and intestines, then carried in the bloodstream to the thyroid, where it is taken up by the gland.  Radioactive iodine only affects the thyroid gland. Thyroid cells are the main target in the body that can absorb iodine, so there is very little radiation exposure to the rest of the body's cells.  While in the thyroid gland, the RAI disrupts the function of some of the thyroid cells - the more radioactive iodine given, the more cells cease to function.  As the cells stop functioning, excessive amounts of thyroid hormones are no longer produced, and symptoms of hyperthyroidism begin to disappear with the risk of hypothyroidism. (It might seem odd to replace one disorder with another, but hypothyroidism is much easier to treat on a long-term basis than hyperthyroidism. )

Question 27

RAI

Answer 27

• Concentrates in thyroid and destroys tissue • Patients eventually develop hypothyroidism and need thyroid replacement therapy • Effectiveness monitored q 4-6 weeks • RAI is shed in stool, urine, saliva -precaution is necessary • Avoid body fluid contact with others for 48-72 hours after treatment • Double flush toilet • Contraindicated with: o Pregnancy (delay until 6 months post-treatment) o Breastfeeding

Question 28

Radioactive Iodine Uptake Test –=

Answer 28

measures absorption by the thyroid gland (calculated dose given (po or IV), thyroid is scanned in 24hr of distribution of RAI The iodine is concentrated in the thyroid gland The dose of radiation with these tests is very small and has no major side effects to the patient Special precaution when nursing these patients – isolation rooms, avoid contact with body fluids RAI is excreted in the urine, stool and saliva

Question 29

A Special Caution for Women 

Answer 29

Pregnant women or women who want to become pregnant in the next 6 months should not use radioactive iodine, as the treatment can destroy the fetus's thyroid and impair its development. Women should wait a year before conceiving if they have been treated with the therapy. Women who are breast-feeding should also not use radioactive iodine.

Question 30

Thionamides

Answer 30

Propylthiouracil (PTU) and methimazole For mild disease or contraindications to RAI Used in hyperthyroidism to prevent the surge of thyroid hormones that occurs after surgical treatment or during radioactive iodine treatment Given over 12-18 months Risk of relapse Patients assessed every 3 months Side effects - May cause liver and bone marrow toxicity

Question 31

Iodine Therapy

Answer 31

``` Inhibits thyroid hormone release Rapid onset Often used to treat thyrotoxicosis or thyroid storm Adjunct therapy for RAI Can be used prior to surgery Eg: potassium idodide Effects last only a few weeks ```

Question 32

Surgery

Answer 32

• Removal of entire thyroid gland or subtotal thyroidectomy • Risk of complications o Hemorrhage, laryngeal edema, vocal cord paralysis • Used when RAI contraindicated or patient preference o Pregnant or planning to be in next 6 months

Question 33

Post surgery: Hypothyroidism -

Answer 33

This more often occurs when the entire thyroid is removed, but it can still happen when only part of the thyroid is removed. To compensate for the lack of thyroid hormones, the patient will take thyroid replacement therapy for life

Question 34

Hypocalcemia:

Answer 34

the body may be more prone to a temporary period of hypocalcemia that responds well to oral calcium supplements with full recovery. Occurs because hyperthyroidism can deplete the body of its normal calcium stores before surgery, and it takes some time to replenish this after surgery

Question 35

Beta-Blockers

Answer 35

``` • Adjunctive therapy • Patients with atrial fibrillation with rapid ventricular response • May also reduce : o Body temperature o Diaphoresis o Tremors o Palpitations o Anxiety ```

Question 36

Graves’s Eye Disease

Answer 36

• Findings only seen with hyperthryoidism caused by Graves’ disease • Exophthalmos o Wide-eyed, startled look o Lid retraction o Globe and lid lag o May have impaired vision o Dry eyes (lid cannot close)-risk for corneal abrasion, infection o Redness, tearing, bloodshot, photophobia

Question 37

Opthalmopathy

Answer 37

* Treatment for hyperthyroidism does not improve the eye and vision problems * Treatment is symptomatic * Elevate the head at night * Eye lubricant * Dark Glasses for photophobia * Steroids or Diuretics may be used

Question 38

Thyroid Storm

Answer 38

* Due to too much thyroid hormone (induced by stress, infection, too high dose of thyroid medication or overdose of thyroid medication) * Exaggerated hyperthyroidism S & S * Mainly due to increased metabolic rate and oxygen demands * Extreme temperature (40.7 C)**cardinal sign * Severe tachycardia * Cardiac dysrrhythmia, HF and shock * Restless, agitation, seizures * N & V & D * Weakness & confusion or disorientation

Question 39

Thyroid Storm: Treatment

Answer 39

``` Continuous cardiac monitoring Supplemental oxygen IV access for fluid resuscitation Risk of hypovolemic shock Monitor intake and output to ensure accurate fluid replacement Administer PTU or methimazole and iodine Beta-blockers Ice packs & cooling blankets Acetaminophen Monitor cardiac rhythm, VS, I & O ```

Question 40

Hyperthyroid: Nursing Assessment and Management

Answer 40

• Assess apical pulse, BP and temperature q 4h • Teach patient to report palpitations, dyspnea, vertigo, chest pain • Immediately report temperature increase of 0.6°C o (ie: 37°C increases to 37.6° C) • Assess cardiac status • Reduce stimulation • Promote comfort • Administer meds as ordered

Question 41

Nursing Diagnoses: Hyperthyroidism

Answer 41

* Imbalanced nutrition: less than body requirements * Hyperthermia related to increased metabolic rate * Fatigue related to sleep deprivation * Potential for hypertension and cardiac failure

Question 42

Thyroid Disorders: Nursing Considerations

Answer 42

• Ensure patient aware of long term nature of therapy and follow up, especially with changes to health status • Teach S &S of hypo and hyperthyroidism • Monitor TSH level every 6-8 weeks until normal • Monitor TSH annually thereafter or if S & S reported • TSH level normal range 0.5 to 5 mU/L • Teach S & S of complications & when to call 911 • Monitor/assess for: o Anemia, hyperlipidemia, depression, menstrual changes, abnormal BP, electrolyte disturbances, blood glucose changes