TH and PTH Flashcards
(127 cards)
1
Q
The thyroid gland secretes what hormones?
A
Secretes T3, T4, and calcitonin
2
Q
What inhibits the secretion of TSH and TRH?
A
T3/T4
3
Q
T4 is converted to T3 primarily where?
A
Liver
4
Q
What is the role fo T3/T4?
A
Regulates metabolism and HR/contractility, involved in normal growth, maturation, and development
5
Q
What is the best initial test to check thyroid function?
A
TSH levels
6
Q
Free T4 is biochemically active and used to evaluate what?
A
Abn TSH
7
Q
Fatigue, constipation, cold intolerance, hair loss, brittle nails, menstrual irregularities, arthralgia, myalgia, depression, decreased libido, and erectile dysfunction are indicative of what?
A
Hypothyroidism
8
Q
On exam you notice: slow speech, thinning hair, perioribtal edema, bradycardia, muscle weakness and delayed DTRs. What is your suspected DX?
A
Hypothyroidism
9
Q
What is the cause for the destruction of the thyroid gland in Hashimoto’s?
A
Autoimmune-mediated
10
Q
What is Hashitoxicosis?
A
Early stage of Hashimoto’s marked by inflammation +/- transient hyperthyroidism
11
Q
Pregnancy, rediation exposure, and iodine intake can be precipitating factors for what disase?
A
Hashimoto’s thyroiditis
12
Q
What antibodies will be positive in Hashimoto’s?
A
TPO Ab and TgAb
13
Q
What is the goal of tx in pt w/ hypothyroidism?
A
Maintain euthyroid state, relieve sx, decrease goiter size if present
14
Q
What is the pharmacologic treatment for hypothyroidism?
A
Synthetic thyroxine (T4) replacement = Levothyroxine
15
Q
Ferrous sulfate, calcium carbonate, protein pump inhibitors and bile acid resins will interfere with the absorption of what HRT?
A
T4
16
Q
What are the most important considerations when treating hypothyroidism with levothyroxine? (3)
A
Weight based (start low and titrate every 4-8 weeks), take on empty stomach, mindful of meds that interfere w absorption
17
Q
When should you recheck TSH after starting T4 HRT?
A
6 wks (expect sx improvement w/in 2-4 wks)
18
Q
Once a hypothyroid pt is stable, when should TSH be rechecked?
A
Annually
19
Q
What pt edu is important for T4 HRT? (2)
A
Life long tx, medication compliance
20
Q
If TSH persistently elevated, what should you consider? (3)
A
Noncompliance, malabsorptive process, binding substances
21
Q
How will a pt with subclinical hypothyroidism present?
A
Mild or vague non-specific sxs
22
Q
The following are consequences to what condition: NASH, neuropsychiatric sxs, infertility/ miscarriages, increased risk of CV disease
A
Subclinical hypothyroidism
23
Q
Treatment is recommended in pts w/ subclnical hypothyroidism if TSH is ≥ what?
A
10 (tx if controversial if 4.5-9.9)
24
Q
When should repeat TSH and T4 levels be measured for subclinical hypothyroidism?
A
Repeat TSH and T4 after 1-3 months to confirm dx
25
When should you repeat TSH and T4 levels immediately with suspicion of subclinical hypothyroidism?
Pregnancy or during fertility treatment
26
Hypothyroidsm induced by stroke, HF, infection or trauma, resulting in high TSH and low T4 is concerning for what?
Myxedema coma
27
TSH levels are tightly regulated by levels of what?
Serum levels of T4 and T3
28
FT4 is more diagnostically relevant than TT4 and is used to evaluted what hormone?
TSH levels
29
Thyrotropin receptor antibody (TRAb) is most often found in?
Hyperthyroidism (Grave's)
30
What functional study is used to evaluted suppressed TSH?
Radioactive Iodine/thyroid uptake scan
31
What imaging study is used to assess structure of the thyroid gland tissue and nodules?
US
32
What is the single most accurate, reliable, cost effective test to DX thyroid CA?
Fine needle aspiration
33
Endogenous hyperthyroidsm is due to what?
Overproduction of thyroid hormone
34
What are the 4 most common causes of endogenous hyperthyroidism?
Graves' disease, toxic multinodular goiter (MNG), toxic adenoma, thyroiditis
35
What are the most common causes of exogenous hyperthyroidism? (3)
Iatrogenic (over-replacement in hypothyroidism, suppressive therapy, intentional for thyroid cancer)
36
What lab values would you expect to see with primary hyperthyroidism?
Low TSH, high FT4, high T3
37
What is the most common cause of primary hyperthyroidism?
Grave's disease
38
What lab values would you expect to see with subclinical hyperthyroidism?
Low TSH, normal FT4, normal T3
39
What lab values would you expect to see with T3 toxicosis?
Low TSH, normal FT4, high T3
40
Opthalmopathy (exophthalmos, proptosis, lid retraction, lid lag, stare) is a common sign of what?
Graves' disease
41
Radioactive iodine uptake and scan is used to evaluate/dx what?
Hyperthyroidism
42
What uptake % is normal on radioactive iodine uptake and scan?
15% uptake after 6 hrs
43
Diffuse high/ elevated uptake on radioactive iodine uptake and scan indicates what?
De novo synthesis of hormone
44
Diffuse low/decreased uptake after a radioactive iodine and uptake sckin can indicate what? (2)
Inflammation/destruction of thyroid tissues (thyroiditis) or extrathyroidal source of thyroid hormone (factitious thyrotoxicosis)
45
What will Graves' show on a radioactive iodine and uptake scan?
Diffuse uptake
46
What will a nodule or toxin MNG show on a radioactive iodine and uptake scan?
Focal Irregular uptake
47
What is indicated by a hyperfunctioning "hot" nodule? (2)
Increased focal/irregular uptake, rarely malignant
48
What is indicated by a hypofunctioning "cold" nodule? (2)
Decreased focal/irregular uptake, more likely to be malignant
49
If you identify a cold nodule on radioactive iodine scan, what additional test should you consider?
FNA
50
What are the treatment options for Graves'? (4)
Beta blockers (sx control), antithyroid drugs (Methimazole, PTU), radioactive iodine ablation, surgery
51
What is the most common cause of primary hypothyroidism?
Hashimoto's thyroiditis (autoimmune)
52
What are the 2 different types of central hypothyroidism?
Pituitary (secondary) or hypothalamic (tertiary)
53
What will TSH and FT4 levels show with central hypothyroidism?
Both low
54
If TSH and FT4 levels are low and you suspect central hypothyroidism, what should the next step be?
Pituitary MRI
55
What is the non-pharmacologic treatment for iatrogenic hypothyroidism?
Radioactive Iodine uptake scan
56
What medications can cause iatrogenic hypothyroidism? (4)
Lithium, amiodarone, other iodine-containing drugs, contrast agents
57
What labs would you expect to see w/ primary hypothyroidism?
High TSH, low FT4, normal or low T3
58
What labs would you expect to see w/ subclinical hypothyroidism?
High TSH, normal FT4, normal T3
59
What labs would you expect to see w/ central hypothyroidism?
N/low TSH, low-normal or low FT4, normal or low T3
60
In primary hypothyroidism, the serum TSH is increased in a reflex effort to stimulate what?
The failing gland (represented by low serum FT4)
61
Pt presents for a routine PE when you note a thyroid nodule. How do you proceed?
TSH and US first
62
What % of nodules are benign vs cancerous?
95% benign, 5% cancerous (nodules are common, but rarely malignant)
63
Most malignant thyroid nodules are what?
Papillary carcinoma (most common but least aggressive and spreads locally)
64
When evaluating a thyroid nodule, if TSH is N or elevated, what should be ordered next?
Check for TPO antibodies
65
If low TSH and low FT4 what is the most likely cause of hypothyroidism?
Central (secondary or tertiary)
66
What is the treatment for myxedema coma?
IV T4 and T3 (and supportive measures)
67
Weight loss, increased appetite, heat intolerance, tachycardia, papitations, anxiety, and nervousness are concerning for what?
Hyperthyroidism
68
In primary hyperthyroidism, the serum TSH is decreased in response to whatt?
Excess T4/T3 (negative feedback loop)
69
What test is used to determine the etiology of hyperthyroidism?
Radioactive iodine uptake scan
70
When is a radioactive iodine uptake scan contraindicated?
Pregnancy and breastfeeding
71
What is the cause of Graves' disease?
Autoimmune-mediated stimulation of thyrotropin receptor
72
What is the 2nd most common cause of hyperthyroidism?
Toxic adenoma / toxic multinodular goiter (MNG)
73
Focal hyerplasia of thyroid follicular cells is aka what?
Toxic adenoma
74
What is toxic MNG?
Thyroid nodules
75
Pt presents with obstructive sxs such as cough, dysphagia, dyspnea. What should you be concerned for?
Toxic adenoma / toxic multinodular goiter (MNG)
76
Will TRAb be postive or negative with Toxic adenoma or toxic MNG?
Negative
77
What is an extreme form of severe thyrotoxicosis that is an immediate threat to life?
Thyroid storm
78
What are the triggers of a thyroid storm? (3)
Stressful illness, thyroid surgery, RAI administration
79
What is the tx for thyroid storm? (3)
ICU, PTU/methinmazole (thionamides), B-blocker, iodine, glucocorticoids
80
What medication do you give for sx control in hyperthyroid pts?
B-blockers (typically combine w/ thionamides (methimazole, PTU))
81
What will labs for TSH, T4 and T3 show for thyroid storm?
Low TSH, high T4 and T3
82
Marked agitation, delirium, fever, tachycardia, vomiting/ diarrhea, dehydration, and psychosis is concerning for what?
Thyroid storm
83
What is the 1st line tx for hyperthyroidism?
Thionamides: Methimazole (DOC), PTU if pregnant
84
What is definitive tx for hyperthyroidism? (2)
Radioiodine ablation (1st line) or surgery
85
When is radioiodine contraindicated? (3)
Pregnant, breast feeding, contact w/ children/pregnant women
86
What are the indications for thyroidectomy over radioiodine ablation? (5)
obstructive symptoms, toxic adenoma, MNG, active ophthalmopathy, mod-severe disease
87
What is defined as inflammation of the thyroid gland that may be painful or painless and characterized by dysfunction?
Thyroiditis
88
Hx of viral illness, glandular enlargement with radiating pain, and associated fever, fatigue, malaise, anorexia and myalgia is concerning for what?
Subacute thyroiditis
89
What is the course of thyroiditis?
hyperthyroid (weight loss) → euthyroid → hypothyroid (weight gain) → recovery/euthyroid
90
Is subacute thyroiditis more of a clinical or laboratory diagnosis?
Clinical
91
What is used in the management of subacute thyroiditis?
Aspirin/ NSAIDS +/- prednisone
92
What levels should be monitored in subacute thyroiditis?
TSH
93
What are the RFs for malignant thyroid nodules? (3)
Hx of head/ neck radiation or family hx of thyroid cancer, multiple endocrine neoplasia (MEN) type 2
94
Thyroid US will help guide what procedure?
FNA biospy
95
What characteristics of a thyroid nodule are benign? (4)
Purely cystic, colloid, <1.0 cm, no suspicious features
96
What characteristics of a thyroid nodule are concerning for malignancy? (8)
Hypoechoic, > 1.0 cm, taller > wide, solid, irregular margins, microcalcifications, extrahyroidal extension, associated cervical lymph nodes
97
What are the types of thyroid cancer? (4)
Papillary, follicular, medullary, anaplastic
98
What is the most aggressive type of thyroid cancer?
Anaplastic
99
What type of thyroid cancer is more aggressive than papillary, and has the ability to metastasize to bone, brain, lung, and liver?
Follicular
100
What is the first imaging performed when evaluating for thyroid CA?
Thyroid US
101
What type of thyroid cancer is sporadic, familial and assocaited with MEN?
Medullary
102
A palpable, firm, nontender nodule that can cause neck discomfort, dysphagia, or hoarsenss is concerning for what?
Thyroid CA
103
What is 1st line treatment for thyroid cancer?
Thyroid lobectomy or total thyroidectomy (pending features)
104
What might follow surgery for the treatment of thyroid cancer to destroy remaining tissue?
Iodine ablation
105
Following surgical intervention of thyroid cancer, what is used to prevent hypothyroidism and to minimize potential TSH stimulation of tumor growth?
HRT (T4 hormone therapy)
106
What does PTH regulate and what impact will elevated levels of PTH have?
Regulates Ca. Excess PTH can lead to hypercalemia (low levels of PTH will lead to hypocalcemia)
107
What is the most common etiology of hypoparathyroidism?
Acquired (post-thyroidectomy, head and neck radiation)
108
What are functional etiologies of hypoparathyroidism?
Hypo or hypermagnesemia
109
Hypoparathyroidism presents w/ sx of hypocalcemia. What would you expect to see on exam?
Prolonged QT on EKG, chovestek sign, trousseau phenomenon (carpel spasm after brachial artery occlusion), tetany or seizures
110
What lab values will be expected to be low with hypoparathyroidism? (2)
PTH and calcium
111
What lab values will be expected to be N or low with hypoparathyroidism? (2)
Vit D and magnesium
112
What lab values will be expected to be high with hypoparathyroidism? (1)
Phosphate
113
If tetany or prolonged QT interval (sever hypoparathyroid), what is the medication tx?
IV calcium gluconate
114
If hyperphosphatemia what is the medication tx?
Phosphate binders to protect kidney and help w/ excretion
115
What is defined as deficient or absent secretion of PTH?
Hypoparathyroidism
116
If mild hypoparathyroidism what is the tx?
Calcitriol and oral Ca carbonate and vit. D
117
What is the most common cause of primary hyperparathyroidism?
Parathyroid adenoma (parathyroid CA = rare)
118
What is defined as dysfunction of normal regulatory feedback mechanisms resulting in excess PTH?
Hyperparathyroidism
119
Excess secretion of PTH in response to hypocalcemia/ hyperphosphatemia is defined as what?
Secondary hyperparathyroidism
120
CKD results in a decreased GFR, what impact does this have on phosphate, Ca and PTH?
Increase phosphate, Decreased Ca and increased PTH
121
What does "bones, stones, abd moans, psychiatric groans" represent?
Fragile bones/ arthralgia/ bone pain, kidney stones, abd pain/ N/ V, psychosis, depression, delirium
122
"Bones, stones, abd moans, psychiatric groans" related to what condition?
Hyperparathyroidism
123
What additional test do you need to order to evalute bone mineral density in pts with hyperparathyroidism? What disease are you evaluating for?
DEXA scan (duel energy XR absorptiometry). Osteopenia & osteoprosis
124
What labs will you expect to see with secondary hyperparathyroidism?
High PRH, low calcium, high phosphate
125
What labs will you expect to see with primary hyperparathyroidsm?
High PTH and Ca. Low Phosphate
126
Ca restriction, avoidance of HCTZ, and bisphophonates is the tx for what disease?
Hyperparathyroidism
127
What is the definitive treatment for hyperparathyroidism?
Parathyroidectomy
