Thyroid and Parathyroid Disease Flashcards
Hyperthyroidism: Definition
sustained increase in synthesis and release of thyroid hormones (T3, T4, and calcitonin) by thyroid gland
occurs more often in women
highest frequency between ages 20-40 years
Hyperthyroidism: Causes
Most common: Graves disease
Other causes:
- toxic nodular goiter
- thyroiditis (treat cause)
- excess iodine intake
- pituitary tumors
- thyroid cancer
Hyperthyroidism: Types
subclinical hyperthyroidism:
- serum TSH level below O.4 mlU/L
- normal T4 and T3 levels
overt hyperthyroidism:
- low or undetectable TSH
- increased T4 and T3 levels
- symptoms may or may not be present
*normal TSH = 0.4-4.0 mlU/L
Grave’s Disease: Etiology and Pathophysiology
autoimmune disease:
- diffuse thyroid enlargement
- excess thyroid hormone secretion
causative factors interact with genetic factors
women are 5x more likely than men to develop Grave’s disease
Grave’s Disease: Clinical Manifestations (eyes, cardio, respiratory, GI)
related to effect of thyroid hormone excess:
- increased metabolism
- increased tissue sensitivity to sympathetic nervous system stimulation
- goiter
eyes:
- opthalmopathy: abnormal eye appearance or function
- exophthalmos: increased fat deposits and fluid, eyeballs forced outward
cardiovascular:
- systolic HTN
- bounding, rapid pulse, palpitations
- increased CO
- cardiac hypertrophy
- systolic murmurs (S3 and S4 sounds from extra fluid)
- dysrhythmias
- angina
respiratory system:
- dyspnea on exertion
- increased RR
GI:
- increased appetite, thirst
- weight loss
- diarrhea
- splenomegaly
- hepatomegaly
Grave’s Disease: Clinical Manifestations (skin, musculoskeletal, nervous, reproductive, other)
Skin:
- warm, smooth, moist
- think, brittle nails
- hair loss
- clubbing of fingers; palmar erythema
- fine, silky hair; premature graying in men
- diaphoresis
- vitiligo: loss of pigmentation in skin
musculoskeletal:
- fatigue
- weakness
- proximal muscle wasting (in limbs)
- dependent edema
- osteoporosis (d/t calcium imbalance)
nervous:
- hyperactive deep tendon reflexes
- nervousness, fine tremors
- insomnia, difficulty focusing eyes
- lack of ability to concentrate
- stupor, coma
reproductive:
- menstrual irregularities
- amenorrhea
- decreased libido
- decreased fertility
- impotence and gynecomastia in men
other manifestations:
- intolerance to heat
- elevated basal temp
- lid lag, stare
- eyelid retraction
- rapid speech
Grave’s Disease: Dx
-decreased TSH (less than 0.4)
RAIU test: small amount of radioactive material is injected into body and images are taken over time to see how much of radioactive iodine is taken in.
- distinguishes Grave’s disease from other forms of thyroiditis
- high uptake = Grave’s disease or hyperfunctioning nodule
- low uptake = thyroiditis or cancer
Grave’s Disease: Tx
antithyroid medications
radioactive iodine therapy (RAI)
surgery
Grave’s Disease: Drug Therapy
useful in tx of thyrotoxic states
not considered curative
- antithyroid drugs
- SSKI
- beta-adrenergic blockers
Grave’s Disease: Antithyroid Drugs
PTU and methimazole (Tapazole)
- inhibit thyroid hormone synthesis
- improvement in 1 to 2 weeks
- results usually seen within 4 to 8 weeks
- therapy for 6-15 months (depending on reason for taking this, if it’s something that can be fixed then they can be tapered off the med, but they may have to take it life-long if it cannot be fixed)
Grave’s Disease: Potassium Iodine
Potassium Iodine (SSKI) and Lugol’s solution
- inhibit synthesis of T3 and T4 and block their release into circulation
- decrease vascularity of thyroid gland, making surgery safer and easier
- maximal effect w/in 1 to 2 weeks
- also used in thyroid storms (thyrotoxicosis)
- stains teeth, so mix with water or juice and drink with straw
manipulation of thyroid gland releases hormones (like a sponge), so you want to make it smaller, less vascular (reduce goiter) before removal
Grave’s Disease: beta-adrenergic Blockers
longer acting beta blockers used: propranolol (Inderal) and atenolol (Tenormin)
symptomatic relief of thyrotoxicosis (does not decrease the hormones)
blocks effects of sympathetic nervous stimulation
- decrease tachycardia, nervousness, irritability tremors
- tx sx, does not decrease thyroxine levels
- tx tachycardia and palpitations until thyroid levels are normal
RAI
Radioactive Iodine Therapy
- tx of choice for most nonpregnant adults
- damages or destroys thyroid tissue
- delayed response of up to 3 months
- treated with antithyroid drugs and beta blockers before and during first 3 months after
given outpatient if they can adhere to post therapy procedures
- must have own bathroom (flush 2-3x after each use)
- drink lots of water
- eat well
- use stool softener
- separate laundry
- no crowds
- prepare own food, not food for others bare handed
- stay away from pregnant people and children
could have sx of hypothyroidism after requiring lifelong levothyroxine
*oral care after for thyroiditis/parotiditis cause it can cause mucosal issues
Nutritional Therapy for RAI
high calorie diet (4000-5000 cal/day) d/t increased metabolism
- 6 full meals/day w/ snacks in between
- protein intake: 1 to 2g/kg of ideal body weight
- increased carb intake
- avoid highly seasoned and high-fiber foods
- no caffeine
Grave’s Disease: Surgical Therapy Indications
Indications:
- large goiter causing tracheal compression (causing airway issues)
- unresponsive to antithyroid therapy
- thyroid cancer
- not a candidate for RAI
- need rapid reduction in T3 and T4 levels (like if you are in a significant thyroid storm causing life threatening issues)
Grave’s Disease: Surgical Therapy
Subtotal thyroidectomy:
- preferred surgical procedure
- involves removal of 90% of thyroid (allows some thyroid to still be used to meet demands of hormones, may need tx of levothyroxine, but thyroid can undergo hyperplasia and grow to meet demands on its own)
minimally invasive (robotic surgery or endoscopic thyroidectomy)
Grave’s Disease: Nursing Implementation (preoperative care)
- give medications to achieve euthyroid state
- give iodine (SSKI) to decrease vascularity
teach:
- leg exercises to prevent DVT’s and PE’s
- head support
- neck ROM (don’t want to lose mobility in neck but do not do neck flexion or this will put stress on sutures and can cause bleeding)
Grave’s Disease: Nursing Implementation (post-operative care)
monitor for complications:
- hypothyroidism
- hypocalcemia
- hemorrhage
- laryngeal nerve damage (some hoarseness expected, but they should be able to control volume of speech, if not d/t nerve damage)
- thyrotoxicosis
- infection
maintain patent airway:
- need to have advanced airway option in pt room in case of airway problem
- monitor for laryngeal stridor from hypocalcemia (d/t manipulating thyroid which will release calcitonin)
tx laryngeal stridor w/ IV calcium (have readily available)
semi-fowlers
support head with pillow
drain care
Assessing for Hypocalcemia
tingling around mouth or finger tips
- chvostek’s sign (facial nerve spasm when tapped)
- trousseau’s sign (carpal spasm)
Grave’s Disease: Nursing Implementation (post-operative home discharge teaching for removal of thyroid)
- monitor hormone balance periodically
- decrease caloric intake once euthyroid is established to prevent weight gain
- adequate but not excessive iodine intake
- regular exercise
- avoid high temps
- regular follow-up care
complete thyroidectomy:
- sx of hypothyroidism
- need for lifelong thyroid hormone replacement
Acute Thyrotoxicosis: Thyroid Storm
- physiologic effects/clinical syndrome hypermetabolism
- results from increased circulating levels of T3 or T4, or both
- hyperthyroidism and thyrotoxicosis usually occur together
- excessive amounts of hormones released
- life-threatening emergency
- death is rare when treated early
- results from stressors
- thyroidectomy patients at risk of this d/t manipulation of gland during surgery
Acute Thyrotoxicosis: Manifestations
- severe tachycardia -> heart failure
- shock
- hyperthermia (up to 106F)
- agitation
- seizures
- abdominal pain, vomiting, diarrhea
- delirium, coma
Acute Thyrotoxicosis: Nursing Implementation
- necessitates aggressive treatment (b/c it’s life threatening)
- give medications that block thyroid hormone production and SNS
- monitor for dysrhythmias on telemetry (must also have an IV)
- ensure adequate oxygenation
- fluid and electrolyte replacement
- establish trusting relationships (pts are very irritable and restless)
- ensure adequate rest (cool, quiet room, light bed coverings, change linens often d/t diaphoresis)
- encourage and assist with exercise
- if exophthalmos present: apply artificial tears to relieve eye discomfort, restrict salt and elevate head of bed, dark glasses, tape eyelids closed if needed for sleep, ROM of intraocular muscles.
Hypothyroidism: Definition
deficiency of thyroid hormone
causes general slowing of metabolic rate
more common in women than in men
Hypothyroidism: Types
subclinical hypothyroidism:
- TSH is greater than 4.5
- T4 levels normal
- Affects up to 10% of women over 60
nonthyroidal illness syndrome (NTIS)
- found in critically ill patients
- low T3, T4, and TSH levels
- corrects after the cause is resolved
Hypothyroidism: Etiology and Pathophysiology
primary hypothyroidism: caused by destruction of thyroid tissue and defective hormone synthesis
secondary hypothyroidism: caused by pituitary disease (decreased TSH) or hypothalamic dysfunction or (decreased TRH)
iodine deficiency (#1 worldwide cause)
atrophy (#1 US cause):
- Hashimoto’s thyroiditis
- Grave’s disease (stimulation of more thyroid hormones being released causing hyperthyroidism or autoimmune response of antibodies destroying thyroid tissue leading to hypothyroidism)
over treatment of hyperthyroidism
drugs
cretinism if occurs in infancy (d/t deficiencies in utero)
Hypothyroidism: Clinical Manifestations
- systemic effects are characterized by slowing of body processes
- slow onset
- tired, lethargic, impaired memory, low initiative, weight gain
- CV system: decreased cardiac contractility and output -> low perfusion -> low oxygenation, increased serum cholesterol and triglycerides (liver is unable to synthesize same amount of cholesterol), anemia
- respiratory: low exercise tolerance, SOB on exertion
- neuro: fatigue and lethargy, personality and mood changes, impaired memory, slowed speech, decreased initiative, somnolence
- GI: decreased appetite, n/v, weight gain, constipation, distended abdomen from decreased peristalsis, enlarged, scaly tongue, celiac disease
- Integumentary: dry, thick, inelastic cold skin, thick, brittle nails, dry, sparse, coarse hair, poor turgor of mucosa, generalized interstitial edema, puffy face, decreased sweating, pallor
- musculoskeletal: fatigue, weakness, muscular aches and pains, slow movements, arthralgia
- reproductive: prolonged menstrual periods or amenorrhea, decreased libido, infertility
- other: increased susceptibility to infection, increased sensitivity to opioids, barbiturates, anesthesia, intolerance to cold, decreased hearing, sleepiness, goiter
Hypothyroidism: Diagnostic Studies
hx and physical exam
TSH and free T4:
-TSH increases w/ primary hypothyroidism
-TSH decreases w/ secondary hypothyroidism
thyroid antibodies: autoimmune origin (most common cause of hypothyroid goiters)
high cholesterol
high triglycerides
high creatine kinase
low RBCs (anemia)
Hypothyroidism: Interprofessional Care
restore euthyroid state as safely and rapidly as possible
hormone therapy
low-calorie diet
levothyroxine (synthroid):
- start with low dose
- monitor for chest pain, weight loss, nervousness, tremors, insomnia
- increase dose in 4-6 week intervals as needed based on TSH levels
- lifelong therapy
- do not abruptly stop
- teach: s/sx of overdose (thyroid storm)
- don’t adjust dosage (which some people to do for weight loss)
Myxedema Coma
precipitated by infection, drugs, cold, trauma
characterized by: impaired consciousness, subnormal temperature, hypotension, hypoventilation, cardiovascular collapse
treated w/ IV thyroid hormone (levothyroxine IV)
*not given PO b/c of hypo-peristalsis
Myxedema Coma: Nursing Implemetation
Needs acute care:
- mechanical respiratory support
- cardiac monitoring
- IV thyroid hormone replacement
- monitoring of core temperature (they get very cold, use tympanic or rectal)
Thyroid Cancer
thyroid nodules may be benign (95%) or malignant
nodule development increase with age
thyroid cancer is the most rapidly growing cancer in the US
RF: women, white or asian american
exposure to radiation
hx, personal or family, of goiters
Thyroid Cancer: Dx and Tx
Dx: nodules found on routine assessment (firm, palpable, mass)
may have difficulty swallowing
u/s, CT, MRI, RAIU test, biopsy
Tx: surgical removal, RAI, radiation (palliative tx for pts with metastatic thyroid cancer)
Hyperparathyroidism
disorder of parathyroid gland -> increased secretion of PTH -> hypercalcemia
bone resorption causes decreased bone density, cysts, bone weakness
kidney: hypercalciuria with increased phosphate leads to calculi formation
GI: increased calcium absorption via effects from Vit D (synthesis stimulated by PTH)
Hyperparathyroidism: Types
primary hyperparathyroidism: adenoma (most commonly benign), women ages 3-70 years, prior head/neck radiation, increases production of PTH which increase calcium
secondary hyperparathyroidism: conditions that cause hypocalcemia (vitamin D deficiencies, malabsorption, chronic renal failure, hyperphosphatemia)
tertiary hyperparathyroidism: hyperplasia of gland -loss of negative feedback from Calcium levels. Seen in pts with kidney transplants following long period of dialysis.
Hyperparathyroidism: S/O
symptoms: none to severe
- weakness, lethargy depression, confusion (increased need for sleep)
- anorexia, N/V, constipation
- muscle aches and weakness (especially legs)
- HTN
- Osteoporosis
- Nephrolithiasis (kidney stone)
- renal failure, pacreatitis, cardiac changes, fractures
- pathological fx (fx not d/t trauma)
- increased calcium and increased PTH, decreased phosphate
- bone loss in bone density
- adenoma on MRI, CT scans
- kidney stones on abdominal x-ray
Hyperparathyroidism: Surgical Interventions
removal of parathyroid (partial or complete)
autotransplantation: transplant healthy gland tissue in forearm or near sternocleidomastoid muscle -PTH secretion continues maintaining calcium levels - if not adequate then calciums supplements for life
Hyperparathyroidism: Interventions (non-surgical)
monitoring serum PTH, Ca++, phosphorus, kidney function tests, x-rays, bone disease and density
increase ambulation, avoid immobility
high fluid intake, moderate Ca intake
phosphorus supplements (contraindicated if pt at risk for renal calculi)
Hyperparathyroidism: Medications
- biphosphonates: inhibit bone resorption, normalize serum Ca++
- estrogen and progestin therapy reduce serum and urinary Ca++ in post menopausal women
- phosphate supplements to bind calcium
- diuretics increase urinary excretion of calcium
- calcimimetic drugs: sensipar or cinacalcet (increase sensitivity of parathyroid gland to Ca++ leading to dec PTH and Ca++)
Hyperparathyroidism: Nursing Interventions
Post-op: similar to thyroidectomy
- assess for respiratory complications (suctioning, O2, tracheostomy tray available in room)
- hypocalcemia: monitor for tetany (may develop early or days)
- mild sx: tingling of hands and around mouth, usually resolve on own
- severe sx: muscular spasm, laryngospasms (have immediate access to IV calcium for bolus)
assess ability to say name with each assessment (assessing voice quality)
chvostek and trousseau’s sign
Hypoparathyroidism
low circulating PTH, hypocalcemia
iatrogenic cause: accidental parathyroid gland removal or damage
-idiopathic hypoparathyroidism: absence,,fatty replacement or atrophy of gland is rare and associated with other endocrine disorders (antiparathyroid antibodies)
severe hypomagnesmia suppresses PTH
Hypoparathyroidism: S/O
easy fatigue
tetany
painful tonic spasms of muscles (face and extremities)
dysphagia, throat tightness, laryngospasms, chvostek’s and treousseau’s sign
respiratory function affected (spasms of accessory muscle and laryngospasms)
anxiety
labs values can include decrease serum Ca++ and PTH and increased phosphate
Hypoparathyroidism: Interventions
Tetany - IV Calcium
- infuse slowly prevent hypotension, cardiac arrhythmias or arrest
- ECG monitoring required
- venous irritation, inflammation, extravasation leading to cellulitis, necrosis at IV site, and tissue sloughing
- rebreathing- breathe in and out of paper bag or breathing mask (helps treat acute neuromuscular sx)
- decrease CO2 excretion from lungs -> increase in carbonic acid -> decrease in pH -> enhancement of calcium ionization leading to more total calcium to be available in the body
oral calcium supplements:
- take w/ meals
- works better if given in smaller amounts several times a day
Vit D supplements for chronic and resistant hypocalcemia
High calcium foods
Monitor Ca++ levels q3-4 months
S/Sx hypo and hypercalcemia
