Clinical Approach Hyperthyroidism and Hypothyroidism Flashcards
What is the approach to the diagnosis of thyroid disease?
- H&P
- inspection, palpation, and auscultation of the thyroid.
- delphian lymph node
- thyroglossal cyst’
- pemberton’s sign= the presence of facial congestion, cyanosis, and respiratory distress after approximately one minute of having the patient elevate both arms until they touch the sides of the face.
Who are candidates for thyroid disease screening?
- those with autoimmune disease (DM, pernicious anemia).
- first-degree relative with thyroid disease
- history of surgical removal of thyroid tissue or tx with sodium iodide I 131.
- history or radiation to the neck.
- those treated with Amiodarone
- pts over 60 (esp. women)
- psychiatric pts treated with lithium
*** What are the 3 most common thyroid function tests?
- ultrasensitive TSH (best)
- free T4
- free T3
How sensitive is TSH regulation to T3 and T4 levels?
- VERY; when T4/T3 is high, TSH is low, and when T4/T3 is high, TSH will be low
What is subclinical hypothyroidism?
- mildly elevated TSH (5-7) with a NORMAL T4
* may need treatment with Levothyroxine
What is subclinical hyperthyroidism?
- mildly lowered TSH (0.4-5) with a NORMAL T4.
What drugs will decrease TSH secretion?
- dopamine
- glucocorticoids
- octreotide
What drugs will decrease thyroid hormone secretion?
- lithium
- iodide
- amiodarone
- aminoglutethimide
What drugs will increase thyroid hormone secretion?
- iodide
- amiodarone
What is iodide inducing hyperthyroidism?
- Jod basedow phenomenon
What is iodide inducing hypothyroidism?
- wolff chaikoff pheonomenon
What drugs can decrease the absorption of thyroid hormone?
- colestipol
- cholestyramine
- aluminum hydroxide
- ferrous sulfate
- sucralfate
What is thyroiditis?
- inflammation of the thyroid gland.
** What is the most common cause of inherited hypothyroidism (thyroiditis) in the U.S.?
- Hashimoto’s thyroiditis (struma lymphomatosa)= autoimmune destruction of the thyroid gland.
- thyroid peroxidase antibody
** What is subacute granulomatous (De Quervain) thyroiditis?
- granulomatous thyroiditis (hypothyroidism) that follows a viral infection.
- presents as a tender thyroid with transient hyperthyroidism.
- self-limited
Is hypothyroidism insidious?
- YES
What are the symptoms of hypothyroidism?
- tiredness, lethargy, weight gain
Can Hashimoto thyroiditis present with a goiter?
- YES, but it does not have to.
What is the most common acquired form of hypothyroidism?
- postablative hypothyroidism
* aka a pt becomes hypo by treating hyperthyroidism.
What are the cardiovascular effects of hypothyroidism?
- increased peripheral resistance (due to lack of vasodilation via thyroid hormone)= cool distal extremities.
- elevated diastolic BP
- decreased HR
- “Myxedema heart” (pericardial effusion).
What is Myxedema?
- hypothyroidism in older children or adults.
- dough-like feeling and hyperpigmentation of extremities due to lymph-edema (not vascular edema).
What are the respiratory signs of myxedema (hypothyroidism)?
- pleural effusion
- CO2 retention
What are the alimentary tract signs of myxedema (hypothyroidism)?
- achlorhydria= low HCl gastric secretions.
- constipation
- weight gain (no more than 5 lbs).
- gastric atrophy (pernicious anemia; autoantibodies against intrinsic factor preventing B12 absorption).
What are the neurological signs of myxedema (hypothyroidism)?
- headache
- somnelescence
- lethargy
What are the muscular signs of myxedema (hypothyroidism)?
- proximal myopathy
- Kocher-Debre Semelaingne syndrome in newborns
- Hoffman’s syndrome in adults
What is the most severe form of hypothyroidism?
- myxedema coma with profound hypothermia (usually during winter months)
When treating myxedema coma, how do we prevent adrenal crisis from occurring?
- give steroids (glucocorticoids) first before giving thyroid hormone (IV levothyroxine) so we don’t increase the demand of the adrenals to the point that they fail.
May a goiter be euthryoid, hyperthyroid, or hypothyroid?
YES
How do we treat Hashimoto thyroiditis?
- thyroid replacement (Levothyroxine)
* early response is loss of edema; diuresis, improved hoarseness, better well being
When should thyroid studies be done for Hashimoto thyroiditis?
- every 6 weeks after each titration of dose.
What is HYPERthyroidism?
- increased level of circulating thyroid hormone.
What is the most common cause of HYPERthyroidism?
- Graves disease
What is Graves disease?
- autoantibody (IgG) that stimulates the TSH receptor (type II hypersensitivity), leading to increased synthesis and release of thyroid hormone.
What are some clinical signs of Graves disease?
- hyperthyroidism
- exophthalmos
- pretibial myxedema (PTM)
- tachycardia
- palpitations
- bounding pulses
- wide pulse pressure
- ATRIAL FIBRILLATION
- high output heart failure
- dyspnea on exertion
- amenorrhea
(aside) What 2 other conditions can cause high output heart failure?
- B1 deficiency (BeriBeri)
2. Paget’s disease
What dermatologic manifestations will you see with hyperthyroidism?
- warm, smooth, glowing skin
- onycholysis of nails
What is Graves dermopathy?
- red, swollen skin, usually on the shins and tops of the feet; otherwise known as pretibial myxedema= deposition of hyaluronic acid.
How do you treat Graves disease?
- B-blockers
- thioamide, methimazol, or PTU
- radioiodine ablation
What is the triad of Graves disease?
- hyperthyroidism with goiter
- exophthalmos
- dermopathy
* may not see this all the time.
What is silent thyroiditis?
- mild to moderate hyperthyroidism with absence of viral syndrome or exophthalmos
- usually no neck pain
- usually occurs postpartum (3 mon`ths).
Are thyroid nodules present in 50% of the population beyond the 5th decade of life?
- YES
* if you see micro-calcifications, think malignancy and biopsy via FNA.
*** What is the most common type of thyroid cancer?
- PAPILLARY CARCINOMA
What will examination of nodule reveal in thyroid cancer?
- hardness, irregular texture
- fixation to adjacent structures
- single nodule
- local lymph node enlargement
What is the exam of choice when examining thyroid nodules for thyroid cancer?
- Ultrasound
What is a potential marker for recurrent thyroid cancer?
- thyroglobulin
In what age group will you see toxic multinodular goiters (hyperthyroidism)?
- elderly
* opposed to Graves in younger individuals.
