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)