Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrine > Thyroid Disorders > Flashcards

Thyroid Disorders Flashcards

1
Q

Peak of hyperthyroidism

A

Ages 20-40 but can also occur over 60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Risk factors of hyperthyroidism

A

-Female sex
-Family hx of thyroid disease
-Age <40 or >60
-Have autoimmune disorders (type I DM, pernicious anemia)
-Consume large amounts of iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which T level is more biologically active?

A

T3 (20-100 times more active)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Subjective findings of hyperthyroidism

A

Anxiety, nervousness, diaphoresis, fatigue, heat intolerance, palpitations, weight loss, insomnia

Fullness/pressure in the neck with enlarged thyroid

Exercise intolerance, tremors, lower extremity edema, weight loss in presence of an increased appetite, menstrual irregularities, frequent bowel movements or diarrhea, exertion dyspnea

Eye complaints - blurred vision, proptosis, photophobia, double vision

Poor concentration, extremely irritable, emotionally labile

Older patients may present with vague symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Physical exam findings of hyperthyroidism

A

Older adult - FTT

HEENT: lid lag, conjunctiva inflammation, decreased visual acuity, exophthalmos, excessive lacrimation

Thyroid may be enlarged, nodules may be palpable, and a bruit may be heard over thyroid gland

Cardiac: tachycardia, irregular pulse, systolic murmurs, widening of pulse pressure

Skin, hair, nails: edema, thinning hair, skin velvety to touch, increased pigmentation, spider angiomas, vitiligo, onycholysis, splitting/spooning of nails, clubbing of digits

Neuro: decreased strength in extremities, fine tremor, hyperreflexia - especially noticeable in achilles tendon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Initial testing results - TSH, FT4, FT3

A

TSH <0.35, elevated T4>12.5, free T4 >1.8

If T4 is normal, order T3 level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Medications that may alter laboratory results in hyperthyroidism

A

Anabolic steroids, androgens, estrogens, heparin, iodine-containing compounds, phenytoin, rifampin, and salicylates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Other testing considerations for hyperthyroidism

A

-Nuclear scintigraphy with radio labeled iodine (123I) or technetium (99Tc) - helps in assessing functional status of thyroid gland
-24-hour radioactive iodine uptake (RAIU) - identifies areas of increased/decreased thyroid function; “hot and cold spots”
-US of thyroid - assists in differentiating cyst from nodule
-Fine-needle biopsy (PREFERRED diagnostic technique to evaluate thyroid masses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Thyrotoxicosis usually seen with

A

Suppressed TSH; if high levels of TSH, consider a rare pituitary tumor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Common causes of hyperthyroidism

A

-Grave’s disease (70%)
-Toxic nodular or multi nodular goiter, toxic thyroid adenoma
-Thyroiditis (usually transient)
-Excessive thyroid hormone intake
-Excessive iodine intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T4 levels may be elevated in

A

-Acute illnesses
-Presence of elevated estrogen levels
-Hyperemesis
-Familial thyroid hormone binding abnormalities, autoimmunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Medications that may increase T4 levels

A

Amiodarone, amphetamines, clofibrate, glucocorticoids (high doses), heparin, heroine, levothyroxine, methadone, perphenazine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Medications that may decrease TSH levels

A

Dopamine, high-dosage glucocorticoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Possible therapies for hyperthyroidism management (may not need if transient or mild)

A

-Radioiodine therapy (>20 years old or failed thioamide therapy)
-Beta-blocker for heart rate control (avoid in asthma, CHF, pregnancy) and symptom relief
-Thiomide therapy in younger or pregnant patients (methimazole [MMI, tapazole] or PTU)
-Thyroidectomy (if airway compromise from enlarging goiter)
-Antibiotic therapy if suppurative type of thyroiditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Thyroid function tests are monitored

A

At least twice a year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Initial thyroid treatment should be evaluated at

A

1 month and at 3 months or more frequent if patient is symptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Therapy duration of antithyroid medications

A

3-12 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

After radio iodine therapy, thyroid function tests should be performed at

A

6 weeks, 12 weeks, 6 months, and annually thereafter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Subclinical hyperthyroidism levels

A

Undetectable TSH levels and normal T4 and T3 levels

Refer to endo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Thyroid storm (thyrotoxicosis) is a potentially life-threatening condition that can be the result of

A

-major stress in someone with uncontrolled hyperthyroid
-associated with radioactive iodine therapy in Graves disease (>1 week after) (rare)
-hyperfunctioning thyroid
-over medication with thyroid hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sudden onset of thyroid storm causes

A

Tachycardia, arrhythmias - leading to:
-HF
-pulmonary edema
-fever (>100.5)
-diarrhea
-nervousness
-confusion
-coma
-death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Postpartum thyroiditis is treated symptomatically with

A

Beta-blockers (caution in BF) or thyroid hormone therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Toxic nodule treatment

A

-beta-blocker therapy followed by radio iodine ablation
-surgical excision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Toxic multinodular goiter treatment

A

-beta-blocker therapy followed by radio iodine ablation (may require repeat)
-surgical excision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Thyroid nodules are palpable if

A

0.5-1 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Risk factors of thyroid nodules/cancer

A

-hx head/neck radiation
-family hx
-age <20 or >60
-male gender
-history of MENS-2 or medullary thyroid cancer
-Cowden disease
-Garner syndrome
-Familial polyposis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Thyroid cancer is characterized by

A

Usually enlarging, painful (associated with hoarseness, dysphonia, dysphagia, or dyspnea), pathologic fractures, thoracic outlet syndrome, symptoms of hyperthyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Thyroid cancer is characterized by thyroid nodules that increase during treatment with

A

Thyroid replacement therapy
-may be hard, fixed; or soft, or fluctuant

29
Q

Diagnostic testing for thyroid nodules

A

-US (evaluate cystic vs. solid components)
-radionucleotide scan (determine hot [hyperfunction] or cold [hypofunction] nodules)
-fine-needle aspiration if >1-1.5 cm if risk factors present for malignancy, hypo echoic or complex (solid and cystic)

30
Q

Thyroid malignancy on US shows

A

Increased vascular flow, hypo echoic nodules, irregular margins, absent halo, micro calcifications, taller (height) or lesion > width

31
Q

Benign features seen on thyroid US

A

Simple cyst, spongiform appearance (multiple micro cysts)

32
Q

Thyroglobin level is a marker for

A

Recurrence of thyroid cancer

33
Q

Patient education for patients undergoing radioactive iodine therapy or scanning

A

-no kissing, sharing food for 5 days
-wash all dishes in dishwasher
-no close contact with children <8 or pregnant women for 5 days
-no breastfeeding
-flush toilet twice after urinating (and wash hands)
-report nervousness, tremors, or palpitations

34
Q

Most common cause worldwide of hypothyroidism

A

Iodine deficiency

35
Q

Primary cause in the U.S. of hypothyroidism

A

Autoimmune processes

36
Q

Hypothyroidism occurs 2-8 times more commonly in

A

Women than men
-higher incidence in whites

37
Q

Iatrogenic (medication) causes of hypothyroidism

A

Amiodarone, dopamine, lithium, interferon-a, thalidomide, stavudine

38
Q

Most common form of autoimmune thyroid disease, with average onset from 30-60 years old

A

Hashimoto’s thyroiditis or primary hypothyroidism

39
Q

Iatrogenic hypothyroidism occurs

A

Following treatment with radioactive iodine or surgery

40
Q

Secondary hypothyroidism occurs due to

A

Failure of the pituitary gland to secrete adequate amounts of TSH

41
Q

Tertiary hypothyroidism occurs due to

A

Inadequate secretion of TRH by the hypothalamus or failure of TRH to activate its cognate receptors within the pituitary (peripheral resistance)

42
Q

Central hypothyroidism occurs due to

A

Direct impingement by tumors on the pituitary gland or the hypothalamus

43
Q

In hypothyroidism, production of T4 is inadequate, causing the thyroid gland to enlarge which stimulates

A

Hypertrophy and hyperplasia of the thyroid gland, resulting in goiter

44
Q

Autoimmune form of hypothyroidism can result, causing

A

Body pathologically recognizes thyroid antigens as foreign

Leads to chronic immune response involving lymphocytic infiltration, vasculizaiton, and fibrosis of the parenchyma

Eventually causes atrophy of the thyroid follicles

45
Q

Destructive thyroid inflammation may occur due to

A

Immune cross-reactivity following viral infections

46
Q

Low levels of thyroid hormones effect every body system, resulting in an overall decrease in

A

Basal metabolic rate

Abnormalities in lipid metabolism

GI slowed in gastric emptying and intestinal transit time, impaired digestion, deficiencies in vitamin B12, iron, folate

47
Q

Endocrine abnormalities of hypothyroidism

A

-menstrual irregularities, infertility, delayed onset of puberty
-insulin resistance
-decreased erythropoiesis

47
Q

Subjective early classic symptoms of hypothyroidism

A

Fatigue, dry skin, slight weight gain, cold intolerance, constipation, heavy menses

47
Q

Accumulation of hydrophilic proteoglycans within interstitial space causes increase in

A

Interstitial fluid - pleural, cardiac, and peritoneal effusions

48
Q

Later symptoms of hypothyroidism

A

Very dry skin, coarse hair, loss of lateral eyebrows, alopecia, hoarseness, continued weight gain, slight impairment in mental ability, depression, decreased libido, hypersomnia

49
Q

Physical exam of hypothyroidism

A

General: facial puffiness, periorbital edema, dry, coarse, thick skin/hair, brittle nails, slow speech, bradykinesia, hoarseness, large tongue, thinning of eyebrows

Thyroid may be enlarged/tender or not palpable

CV: bradycardia, lateralized PMI, mild diastolic HTN
GI: diminished or hypoactive BS
Neuro: hypotonic and hyporeflexic with a prolonged relaxation phase and/or ataxia, edema

50
Q

Which T4 level is preferred?

A

Free T4 rather than total T4

Alterations in hormone protein binding may result in large fluctuations in total serum T4 level

51
Q

Initial testing results for symptomatic or high risk patients of hypothyroidism (e.g., DM, autoimmune disorders, depression, obesity, etc.)

A

-elevated TSH and decreased free T4
-if TSH is low, normal, or insufficiently elevated in presence of low T4 values, central hypothyroidism caused by hypothalamic or pituitary disease should be excluded

52
Q

Subsequent testing of hypothyroidism

A

-CBC - anemia
-chemistry panel
-UA
-lipid panel - elevated LDL and triglycerides
-ECG
-CXR
-TPO antibody/antithyroglobulin antibody
-thyroid US and possible scan if nodules noted
-may need referral for FNA

53
Q

Antimicrosomal antibody (anti-TPO antibody) is diagnostic for

A

Hashimoto’s thyroiditis when titers are high (1:400)

Antithyroglobulin antibody is also increased, but it is not as specific for Hashimoto’s

54
Q

Treatment for hypothyroidism

A

Synthroid 1.6 mcg/kg/day for full replacement

55
Q

Patients who are older or have CAD should begin hypothyroidism treatment with

A

1/2 the expected replacement dose or 12.5-25 mcg/day PO, increasing the dose gradually once every 4-6 weeks

56
Q

Synthroid dosing is best done

A

In the morning to avoid nighttime insomnia

57
Q

What may alter dosing requirements in either direction of the hypothyroid patient?

A

Concurrent severe illness or major surgery

Pregnancy - increase replacement therapy

58
Q

After therapy is initiated for hypothyroidism, check patient’s TSH level in

A

6 weeks

59
Q

Target TSH level

A

0.3-3.0 mcg/dL

60
Q

Once a stable dose of Synthroid is established, check TSH level

A

Biannually or annually

61
Q

Endocrinology specialist is recommended if

A

-a patient has cardiac disease, symptoms of myxedema, or central (secondary or tertiary) hypothyroidism
-signs/symptoms of myxedema, chest pain, or thyrotoxicosis occur after starting HRT
-patients have severe illness or those who present with unusual or confusing lab findings
-patients <18 years old
-pregnant/postpartum patients
-those taking lithium or amiodarone

62
Q

Treatment may affect levels of

A

Phenytoin, lithium, TCAs, estrogen, digitalis, anticoagulants, and indomethacin

63
Q

Medications that interfere with therapy

A

Iron, calcium carbonate, aluminum hydroxide, sucralfate, and tube feedings

64
Q

Diet education

A

Low-fat, high-fiber foods

Increase intake of raw fruits/vegetables, bran or high-fiber cereals and breads, and add unprocessed bran (2 tbsp/day) to cereal or liquids

Bulk-forming laxative containing psyllium may be taken daily

Increase water intake to 6-8 glasses/day

65
Q

The American Thyroid Association recommends treating subclinical hypothyroidism when

A

-TSH level >10
-antithyroid antibodies are present
-serum lipid levels abnormal
-patient smokes
-patient is symptomatic at this TSH level

However, data regarding the treatment of asymptomatic patients with TSH between 4.5-10 are inconclusive

66
Q

If the decision is made not to treat patients, evaluate at

A

6-12 month intervals for evidence of worsening thyroid function

A low dose can be given (0.5-1.0 mcg/kg)

Endocrine (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions