Lecture 9 - Thyroid Disorders Flashcards Preview

Clin Med - Endocrine > Lecture 9 - Thyroid Disorders > Flashcards

Flashcards in Lecture 9 - Thyroid Disorders Deck (52)
Loading flashcards...
1
Q

Who is more likely to get hypothyroidism?

A

women

typically older women?

2
Q

What is our classic screening test for thyroid function?

A

TSH

3
Q

What is the best direct measurement of free T4?

A

go back and PANOPTO this slide 6

4
Q

What is the difference between primary, secondary, and subclinical hypothyroidism?

A

Primary - high TSH with low free T4

Secondary - low T4 and TSH that is low or normal

Subclinical - normal T4 with elevated TSH

5
Q

What is the most common cause of hypothyroidism, worldwide vs in US?

A

worldwide = Fe deficiency

US = Hashimoto’s Thryoiditis

6
Q

What are the TSH and free T4 levels for a pt with primary hypothyroidism?

A

TSH - elevated

Free T4 - low

7
Q

What should you suspect for a pt with elevated TSH and normal free T4?

A

subclinical hypothyroidism

8
Q

A pts lab results are normal TSH with low free T4, what is on your ddx?

A

secondary hypothyroidism

but this is super rare so consider redrawing their labs again

9
Q

For a patient with subclinical hypothyroidism, should they be treated?

A

T4 replacement is made on a case by case basis and depends partly upon the degree of TSH elevation

since they antibodies they might get worse hypothyroidism overtime

10
Q

Levothyroxine

A

the half life of this medication is long so you have to wait for the med to build up before you can test the level —-4 - 6 weeks after dose change

11
Q

What do you tell a pt who is taking levothyroxine, in regards to when to take it and what to do if you forgotten to take a pill?

A

take the medication on an empty stomach

don’t eat for an hour
also if they are taking Ca or iron, don’t take those within 4 hours of taking levothyroxine

if they have forgotten a pill, take 2 the next day

12
Q

What defines overt hyperthyroidism?

A

elevated free T4, T3 or both

with subnormal TSH

13
Q

How do the HTNs differ between hyper and hypothyroidism?

A

Hyper = systolic HTN

Hypo = diastolic HTN

14
Q

How can you measure the potential proptosis in pts?

A

Exophthalmometer

normal in caucasian = 18mm
normal in AA = 22mm

15
Q

You suspect that your pt has hyperthyroidism, you are going to refer them to endocrinology, but first what labs should you do?

A

TRAb - autoantibodies to the TSH receptor
TSI - thyroid stimulating immunology
TBII - thyrotropin - binding inhibitory immunoglobin

board questions might want you to say nuclear medicine uptake and scan but this is expensive

16
Q

How do you treat hyperthyroidism/Grave’s?

A

to help with their sxs while they wait for endocrine referral

if they have tachycardia - propranolol bid (they clear the medication faster)
(also helps block T3 conversion)

Methimazole (instead of PTU d/t liver problems)

17
Q

What is the treatment for thyroiditis?

A

propranolol

treat infection if underlying

18
Q

What categories are included in the dx criterial for thyroid storm?

A
  • Temperature
  • CNS effects/Mental status
  • GI dysfunction
  • HR
  • CHF
  • A fib
  • Precipitating event
19
Q

What should you be thinking as a ddx if you have a pt you are treating with hormone replacement that is doing better and then all of the sudden tanks?

A

adrenal insufficiency? (other autoimmune disorders)

20
Q

Graves Disease

A

Autoimmune attack of the TSH receptor antibodies (TRAB) –activating them
HypERthyroidism (MC cause)

sxs:
ophthalmopahty - exopththalmos, proptosis 
pretibial myxedema (notpitting edema) 
tachycardia
hyperglycemia 
HTN (typically systolic) 
heat intolerance  
Dx:
TSI (thyroid stimulating immunoglobins) 
low TSH 
high T3, T4 
Nuclear medicine uptake and scan (RAIU) - iodine dye --more uptake in the graves thyroid 

tx:
Radioactive Iodine
BB (propranolol) - this decrease tachycardia AND blocks the conversion of T4 to T3
Methimazole - blocks thyroid hormone production

Thyroidectomy - last resort or if pt is pregnant or plans on getting pregnant in the next 6 months (or males want to father in the next 6 months)

21
Q

How do you dx Graves dz?

A

TSI (thyroid stimulating immunoglobins)
low TSH
high T3, T4
Nuclear medicine uptake and scan (RAIU) - iodine dye –more uptake in the graves thyroid

22
Q

How do you tx Graves dz?

A

Radioactive Iodine

BB (propranolol) - this decrease tachycardia AND blocks the conversion of T4 to T3

Methimazole - blocks thyroid hormone production

Thyroidectomy - last resort or if pt is pregnant or plans on getting pregnant in the next 6 months (or males want to father in the next 6 months)

23
Q

What are causes of hyperthyroidism?

A

Graves disease (MC)
Toxic Multinuodular Goiter
TSH secreting pituitary adenoma
Excess intake of T3 or T4

24
Q

What are causes of hypothyroidism?

A

Iodine deficiency
Hashimotos thyroiditis
postpartum thyroiditis
post radioiodine treatment for hyperthyroidism

25
Q

What are the sxs of hypothyroidism?

A
cold intolerance 
weight gain 
goiter
myxedema 
hypoactivity - fatigue, sluggishness, depression 
hoarseness of voice 
bradycardia 
HTN, typically diastolic 
hypoglycemia
26
Q

What are the sxs of hyperthyroidism?

A
Heat intolerance 
weight loss 
goiter
easy bruising 
anxiety 
fine tremors
fatigue 
urinary/deification urgency 
tachycardia 
palpitations
hyperglycermia 
scanty periods (oligomenorrhea) 
HTN - systolic
27
Q

Thyrotoxicosis

A

thyroid hormone excess - not the same thing as hyperthyroidism

28
Q

What are the criteria for thyroid storm?

A
temperature 
CNS effects/mental status 
GI dysfunction 
HR
CHF
Afib
precipitating event
29
Q

Thyroid storm

A

potentially fatal (10-30% mortality) complication of untreated thyrotoxicosis after a precipitating event (surgery, trauma, infection, illness, pregnancy)

sxs:
hypermetabolic state- palpitations, tachycardia, A.fib, high fever, N/V, psychosis, tremors

dx:
decrease TSH, increase T4/T3

tx:
PTU or methimazole (remember that PTU has bad liver SE)
BB
IV glucocorticoids (hydrocortisone, prednisone, dexamethasone)

30
Q

What is the MC cause of hypothyroid in US?

A

Hashimotos thyroiditis

W > M

31
Q

Hashimotos thyroiditis

A

MC cause of hypothyroidism

self destruction of thyroid follicle cells

painless, enlarged goiter (d/t in TSH)
hypothyroid sxs

Thyroid Ab present

tx: levothyroxine (synthetic T4)

32
Q

Levothyroxine

A

synthetic T4 given to hypothyroid pts

dont take within 1 hour of food or 4 hours of Ca/Fe pills

check TSH levels in 6 weeks since half life is 7 days so time to reach steady state would be 30 days

33
Q

What is the MC cause of hypothyroid worldwide?

A

idoine deficiency

34
Q

If a pt presents with an asymptomatic nodule on their thyroid, what do you do?

A

Get US

need biopsy the solid/hypoechoic nodules

never biopsy cystic/fluid nodules because they are ALWAYS benign

35
Q

Starry night

A

microcalcifications seen on some thyroids that indicates a BAD prognosis

36
Q

What thyroid nodules get biopsied?

A

> 1cm SOLID nodules

37
Q

Subacute thyroiditis

A

aka Grandulomatous thyroiditis
aka de Quervian’s thyroiditis

typically viral infection of the thyroid
PAINFUL thyroid
typically presents with hyperthyroidism even though it eventually becomes hypothyroid

NO thyroid Antibodies

Elevated T3/T4

tx: NSAIDS for pain and inflammation

typically returns to normal in a year

38
Q

What do the labs look like for a pt with subacute thyroiditis?

A

elevated T3 and T4

39
Q

What is the treatment for subacute thyroiditis?

A

NSAIDS

NO thyroid medications since this is a viral inflammatory problem

will typically return to normal in 12 months

40
Q

A pt presents with a unilateral, painful thyroid nodule, what should you be suspecting?

A

could be acute thyroiditis -typically caused by an infection via S. aureus

41
Q

Thyroid Nodules

A

60% of people will have a thyroid nodule –incidence increases with age (80% women)

only 5-10% are malignant

US is the best initial testing
solitary nodule is tumor until proven otherwise

get FNA - fine needle aspiration (25 gauge needle)

42
Q

Cold vs hot nodules

A

RIUS - radioactive iodine uptake scan

hot means that the iodine was taken up (remember that the thyroid loves iodine

cold (no/low iodine uptake) is highly suspicious for malignancy

43
Q

Which thyroid cancer is the most common?

A

papillary (80%)

followed by follicular

44
Q

What is the biggest risk factor of papillary thyroid cancer?

A

radiation exposure

45
Q

Who is more likely to get papillary thyroid cancer?

A

MC in young females (20-50 y/o)

least aggressive

distant METS uncommon

excellent prognosis

Hashimotos puts you at an increased risk of papillary carcinoma

46
Q

Who is more likely to get follicular thyroid cancer?

A

40-60 y/o

47
Q

A thyroid nodule is typically benign, unless what kind of presentation?

A

in a pt <20 y/o

ALWAYS be suspicious of a nodule in a young pt

48
Q

Medullary thyroid cancer is associated with …..

A

MEN 2

49
Q

What is the treatment for thyroid cancer?

A

total thyroidectomy

50
Q

Which type of thyroid has the worst prognosis?

A

anaplastic

51
Q

Which thyroid carcinoma arises from the C cells?

A

medullary

Calcitonin excess production

52
Q

What is measure post thyroidectomy in a medullary carcinoma to check for residual disease or recurrence?

A

calcitonin