Upgrade to remove ads
Thyroid Disorders (Farrell)
Terms in this set (65)
how are thyroid disorders tested for?
screening = TSH
free T4 and T3
imaging with ultrasound
causes of primary hypothyroidism
causes of secondary hypothyroidism
isolated TSH deficiency
causes of transient hypothyroidism
thyroditis (illness, postpartum)
incidence of congenital hypothyroidism
~1 in 4000 newborns
(coarse facial features, protruding tongue, stunted growth, severe neurological damage)
most due to
thyroid gland dysgenesis
most newborns appear completely normal at birth
what are potential consequences of congenital hypothyroidism (cretinism)?
permanent neurologic damage results if treatment is delayed = newborn screening in all US states
what is the treatment of congenital hypothyroidism (cretinism)?
levothyroxine (T4) immediately
Gradual destruction of thyroid tissue due to auto-antibodies
Cause is thought to be combination of genetic and environmental risk factors
what is the most common autoimmune hypothyroidism?
prevalence of autoimmune hypothyroidism
1-4 per 1000
though more recent studies suggest higher numbers of undiagnosed
pathogenesis of autoimmune hypothyroidism
of the thyroid gland and
destruction of thyroid follicles
what are some risk factors of autoimmune hypothyroidism? (5)
Infection and stress
Female > Male
what are the symptoms of hypothyroidism?
poor concentration and memory
what are some signs of hypothyroidism?
puffy face/periorbital edema
dry, coarse skin
what are the lab values of primary hypothyroidism?
low free T4 level
what are the lab values of subclinical hypothyroidism?
normal free T4
what are the lab values of secondary hypothyroidism?
normal or low TSH
low free T4
what is the management of primary hypothyroidism?
symptoms may improve within 2 weeks, but steady-state TSH concentrations are not reached for at least 6 weeks
prohormone that is converted to T3 in peripheral tissues
long half-life so once daily dosing
take in AM on empty stomach
how is primary hypothyroidism monitored?
re-check TSH levels after 6 weeks of therapy
if still elevated, may need to increase dose of levothyroxine
continue adjusting every 3-6 weeks until symptoms resolve and TSH levels normalize
then annual testing of TSH levels
what happens if hypothyroidism is not diagnosed or treated?
slowed metabolic pathways
of every organ
myxedema coma presentation
Decreased mental status, hypothermia, hypotension, bradycardia, hypoventilation, hyponatremia, hypoglycemia
Puffiness of face and hands, swollen lips, enlarged tongue
what is the treatment of myxedema coma?
thyroid hormone replacement
what are the causes primary hyperthyroidism?
, toxic goiter/adenoma, functional thyroid carcinoma metastases
what are the causes of secondary hyperthyroidism?
TSH-secreting pituitary adenoma
, thyroid hormone resistance syndrome (very rare)
what is the most common pathogenesis of hyperthyroidism?
autoimmune caused by TSH-receptor antibodies => stimulates thyroid gland growth and thyroid hormone synthesis and release
what is the initial presentation of Hashimoto's thyroiditis?
due to auto-antibodies, then there is lymphocytic infiltration and autoimmune destruction of the thyroid gland =>
seen in Graves' disease
bulging of the eye anteriorly out of the orbit, due to excessive connective tissue deposition in the orbit and extraocular muscles
what are the lab values of primary hyperthyroidism?
Elevated T4 and/or T3
what are the lab values of secondary hyperthyroidism?
elevated free T4
what are the lab values of subclinical hyperthyroidism?
normal free T4
radioactive iodine uptake test
pt swallows radioactive iodine; images are taken with scintillator counter 4-6 hours later
low uptake = thyroiditis
high uptake (diffuse) = Graves' disease
high uptake (nodular) = adenoma or goiter
what is used to manage
decreases palpitations, tachycardia, HTN, tremors, anxiety and heat intolerance
what is used to decrease thyroid hormone in managing hyperthyroidism?
radioactive iodine =
first line drug
once daily dosing
lower side effect profile
not used in 1st trimester of pregnancy due to
is one side effect
not commonly used in children
pt takes a capsule of I-131
taken up mostly by thyroid tissue => causes localized tissue damage => ablation of thyroid gland in 6-18 weeks
what is the consequence of surgery in hyperthyroidism?
requires lifelong levothyroxine post-surgery
what state must the pt be in prior to thyroidectomy?
euthyroid to prevent "thyroid storm" => treat with methimazole and beta blocker
what are some complications of thyroidectomy?
removal of parathyroid glands and recurrent laryngeal nerve damage (vocal cord paralysis)
how is hyperthyroidism monitored?
thyroid function should be checked at 4-6 week intervals until stabilized
pts who have undergone ablation should have thyroid function measured 8 weeks after treatment
frequent monitoring determined by management modality
rare, life-threatening condition
fever, tachycardia, arrhythmia, N/V, diarrhea, agitation, anxiety, stupor/coma
what are precipitating factors for thyroid storm?
surgery, trauma, infection, giving birth (parturition)
what is the treatment of thyroid storm
what are the causes of thyroiditis?
Infectious (usually after viral illness)
Direct chemical toxicity
what is thyroiditis?
inflammation of thyroid tissue with transient hyperthyroidism, usually followed by hypothyroidism and then recovery of thyroid function
how is thyroiditis diagnosed?
clinical diagnosis = recent history of illness, post-partum
labs will be consistent with
, may have tenderness to thyroid
Ultrasound may show normal or enlarged thyroid
radioiodine study will show
what is the management of subacute thyroiditis?
often self limited, most resolve in 3-4 months
NSAIDs for anti inflammatory and pain relief
what is the management of post-partum thyroiditis?
not treatment necessary
nontoxic thyroid nodules
toxic thyroid nodules
Hyperfunctioning thyroid tissue
Same management as hyperthyroidism
what is the most common type of thyroid cancer?
papillary thyroid carcinoma
who most commonly presents with papillary thyroid carcinoma?
what is the prognosis of papillary thyroid carcinoma?
excellent, slow growing
what is the most important risk factor for papillary thyroid carcinoma?
radiation exposure as a child
what is seen microscopically in papillary thyroid carcinoma?
empty-appearing nuclei (orphan annie eyes)
what is the second most common type of thyroid cancer behind papillary carcinoma?
follicular thyroid corinoma
where is follicular thyroid carcinoma most commonly seen?
in iodine deficient areas
what is seen microscopically in follicular thyroid carcinoma?
uniform follicular architecture
medullary thyroid carcinoma
neuroendocrine tumor associated with MEN 2A and 2B
not as common
microscopy of medullary thyroid carcinoma
undifferentiated thyroid carcinoma
very poor prognosis, almost 100% mortality
very aggressive, invades local structures
occurs in older patients
what is the treatment of thyroid cancers?
mainly surgery = partial or total thyroidectomy
chemotherapy and radiation for undifferentiated thyroid cancers
YOU MIGHT ALSO LIKE...
NCLEX-RN Exam | Mometrix Comprehensive G…
Endocrine Final chap 21
Lewis 50 Endocrine Problems
OTHER SETS BY THIS CREATOR
Common hereditary cancer syndromes
Chromosomal Disorders and Genetic disord…
THIS SET IS OFTEN IN FOLDERS WITH...
Thyroid hormone (Wong)
Parathyroid glands/Ca2+/PO4 (Wong)
Endocrine histology (puder)
Thyroid and Parathyroid Disorders