CM: Thyroid Dz Flashcards
What are the characteristics of a normal thyroid?
weighs about 20g
not visible even swallowing until 40g
only isthmus palpable
What is the first test needed in evaluation of a goiter?
serum TSH and free T4
What test can be done to evaluate Hashimotos?
anti-TPO antibodies
What imaging studies are needed to diagnose different pts w thyromegaly?
ultrasound can see size and # of nodules
CXR may show restrosternal extension
CT, esophograms, PFTs may clarify compression of adjacent structures
Radioiodine scans - only indicated in hyper
What tests are useful w a pt w a thyroid nodule?
TSH and free T4
euthyroid –> FNA, ultrasound
hyper –> RAIU
nodule >1cm always gets FNA, <1cm need other info to decide
What physical exam findings are present w hypothyroidism?
delayed relaxation of deep tendon reflexes, coarse dry skin, diastolic HTN, ascites, pericardial effusion, galactorrhea, maybe carpal tunnel, loss of lateral 3rd of eyebrows
What is the pathophysiology behind the manifestations of hypothyroidism?
slowing of metabolic processes
build up of matrix substances in tissue due to depo of GAGs and hyalauronic acid in connective tissue
What labs are seen in hypothyroidism?
normochromic, normocytic anemia
decreased SHBG
hyponatremia
hyperlipidemia
What is myxedema coma and how can it be recognized?
life threatening hypothyroidism usually due to precipitating event
hypothermia, hypoxia, decreased cardiac fxn
What are some physical exam findings in hyperthyroidism?
hyperreflexia, separation of nail from nail bed and softening of nails, skin pigmentation, itching
What are two specific clinical manifestations of Graves?
orbitopathy - exopthalmos
dermopathy (pretibial myxedema due to GAGs)
Why is hyperpigmentation seen in hyperthyroidism?
rapid turnover of glucocorticoids leads to increased ACTH secretion
What findings in RAIU can help diagnose the cause of hyperthyroidism?
Graves - high uptake and big gland
toxic adenoma - uptake in discreet nodule
toxic multinodular - patchy uptake everywhere
thyroiditis have low or undetectable RAIU
How can thyroid storm be recognized?
hyperthermia, arrhythmias, CNS - delirium and seizures
