Thyroid and PTH Flashcards
T3
3,5,3’-triiodothyronine
T4
thyroxine
What are some signs of accumulation of matrix substances that accompany hypothyroidism?
Puffy facies
Loss of eyebrows
Periorbital edema
Tongue enlargement
What are some less common sx of hypothyroidism?
–Decreased hearing –Myalgias/arthralgias/paresthesias –Depression –Menstrual changes –Pubertal delay –Diastolic HTN –Pleural and pericardial effusions –Ascites –Galactorrhea
What labs should you check with hypothyroidism?
TSH, Free T4, T3, BMP (for decreased Na+ and elevated creatinine), lipids and DRUG LEVELS
What two antibodies should be elevated in Hashimotos?
anti-TPO and anti-thyroglobulin
What patients should you screen for hypothyroidism?
Goiter Hx of autoimmune dz hx of head/neck radiation family hx thyroid dz pt on meds that impair thyroid function
What meds impair thyroid function?
lithium amiodarone aminogluthimide interferon alpha thalidomide betaroxine stavudine
What labs do you expect to see in subclinical hypothyroidism?
High TSH and normal T4
What labs do you expect to see with secondary hypothyroidism?
TSH normal (not appropriately elevated) and low T3
What are three T4 replacement drugs?
Levothroid, Levoxyl, Synthroid
Who should you replace T4 in slowly?
elderly and people with cardiac abnormalities
What are two important things to note about replacement of T4 (pt ed)?
Missing a dose should not change levels too drastically
Take on an empty stomach
How fq should you monitor T4?
every 6 weeks initially
eventually yearly
What will bind up T4 and lower therapeutic levels?
estrogen
What should you remember about armour thyroid?
Monitor it more frequently
What are symptoms of subclinical hypothyroidism?
CVD
Nonalcoholic fatty liver disease
Neuropsychiatric symptoms
Miscarriage and low birth weight babies
What lab is unique to Grave’s disease?
Thyroid Stimulating Immunoglobulin (TSH Receptor Antibody)
What are common causes of hyperthyroidism?
Graves early Hashimoto's Autonomous thyroid tissue (adenoma or multinodular goiter) TSH-mediated hyperthyroidism hCG mediated
What are some common causes of thyroiditis?
subacute granulomatous painless postpartum amiodarone induced radiation palpation
What are some common sx of hyperthyroidism?
Skin changes (sweating) Stare and lid lag Graves’ ophthalmopathy Cardiovascular LOW TOTAL AND HDL Impaired glucose tolerance
Signs of hyperthyroidism
normochromic normocytic anemia
bone changes
irritability
What is Grave’s ophthalmopathy?
decreased ocular muscle movement
periorbital edema
conjunctival edema
In addition to Thyroid stimulating immunoglobulin, what other labs are elevated in Graves disease?
Anti-thyroid and anti TPO
ANA and Anti-ds DNA may also be elevated
What test confirms hyperthyroidism?
24 hour radioiodine uptake scan
high uptake=endogenous hormone synthesis
low uptake=inflammation or destruction of gland
CI in PGN/Breastfeeding
Tx options for Graves (hyperthyroidism)
–Beta-blockers –Thionamides •Methimazole •Propylthiouracil (PTU) –Radioiodine ablation –Surgery (last resort)
What signs/symptoms are a/w subacute thyroiditis? How do you treat?
Painful glandular enlargement leads to DYSPHAGIA, sometimes associated with VIRUS
Tx with aspirin
What are the causes of benign thyroid nodules?
multinodular goiter
Hashimoto’s
cysts
Follicular adenoma
What are some causes of malignant adenomas?
CARCINOMAS: Papillary, follicular, medullary, anaplastic
Primary T lymphoma
metastatic carcinoma
What is the most common type of thyroid cancer?
Papillary, best prognosis until stage 4
What is the most aggressive form of thyroid cancer?
anaplastic, highly aggressive
What two questions do you ask when treating a nodule?
Are they cancerous? Think high risk groups
Are they causing dysfunction?
What does a very high TSH mean?
Higher risk for thyroid cancer
You have a suspicious thyroid nodule with normal TSH. What is your first choice for evaluation?
Fine needle aspiration
You have a suspicious thyroid nodule with low TSH. What is your first choice for eval?
Thyroid scan looking for hot nodule or cold nodule
What if you have a hot nodule on thyroid scan?
DON’T BIOPSY IT!
In what high-risk groups are fine needle biopsies recommended for nodules?
Anyone with a high risk history and a nodule greater than 5 MM, with or without suspicious sonograph features
anyone with accompanying cervical node enlargement
Anyone with microcalcifications in nodules
When is FNB recommended for patients with solid nodules?
when HYPOECHOIC and greater than 1 CM
when HYPERECHOIC and less than 1 CM
When is FNB recommended for patients with multi-cystic nodules?
with suspicious ultrasound features and greater than 1.5-2.0 cm
with no suspicious ultrasound features and greater than 2.0 cm
What is FNA not recommended?
with a purely cystic nodule
What should you do when approaching a nodule that is greater than 4 cm?
obtain multiple samples, in general hold off on small samples (less than 1 cm) unless they are high risk
Macro or microfollicular thyroid lesion… Which is more benign?
Macrofollicular with abundant colloid
Pt with irritability, stridor, cataracts, thin/brittle nails, dry/scaly skin, loss of eyebrows, and hyperactive DTRs
hypoparathyroidism
Labs of hypoparathyroidism
Low Ca2+, high phosphate, low urine calcium, normal alk phosphatase
Mg is often elevated
Treatment in ER for acute tetany
IV calcium gluconate and AIRWAY
Treatment for hypoparathyroidism
Ca2+ and vitamin D, +/- Mg
What do you need to avoid in hypoparathyroidism?
Furosemide (loop diuretics)
Symptoms of hyperparathyroidism
Bones, stones, abdominal moans, psychiatric moans, fatigue overtones, SHORT QT
Most likely hyperparathyroidism labs
PTH from 60-500, total serum Ca2+ less than 15
Most likely malignancy labs (ddx hyperparathyroid)
PTH less than 20 with total calcium being less than 15 (mild PTH)
What are normal PTH and Ca2+ labs?
PTH less than 70 with total serum calcium less than 11 (ish… just focus on hypers)
What should you supplement in hyperparathyroidism? Avoid?
Supplement Vit D
Avoid lithium and thiazide diuretics
What is medical management for hyperpara?
IV bisphosphonates (you know the -dronates) or estrogen in post menopausal women
In which diseases is thyroglobulin typically elevated? In which is it typically monitored most closely?
Acute thyroiditis
Graves’ disease
THYROID CANCER
When are TgAb (thyroglobulin antibodies) typically elevated?
Hashimotos»Graves
Used to evaluate the likelihood that Graves patient will eventually become hypothyroid with no destruction of the gland
When are microsomal TPO antibodies seen?
Hashimotos»Graves, also in post-partum thyroiditis
What are Thyrotropin Receptor Blocking Antibodies (TBAb or TSBAb)? In what disease are they elevated?
Antibodies which prevent TSH from binding to the cell receptor, etiology for HYPOTHYROIDISM since it prevents binding
SEEN ONLY IN HASHIMOTO’S
TBI and TBII
GRAVEs»Hashimotos
Low TSH, what do you evaluate?
FT4, FT3, Tg, TPO Ab’s, TgAB’s, TSI
High TSH, what do you evaluate?
FT4 and AB’s (all)
What types of cysts are typically benign?
Homogenous (same types of tissues as opposed to degeneration of tissue)
What if you encounter a heterogenous cyst?
Get T3, T4, antibodies, repeat u/s in 6 months. BIOPSY NODULES GREATER THAN 4MM, wait on smaller than 4 mm (per Roch)
You find a follicular nodule on U/S… What do you do next?
FINE NEEDLE ASPIRATION (TEST QUESTION)
Which PTH test is most indicative of parathyroid disease?
intact PTH (as opposed to total)
