Hypothyroid/thyroiditis Flashcards

Question

# hypothyroid Tx Persistent symptoms despite TSH level in the lower normal range

Answer 1

Combination T3/T4 therapy may be used in select patients Armour thyroid **Levothyroxine plus liothyronine** (Cytomel)

Answer 2

Rare, but **life-threatening condition** Most severe manifestation of hypothyroidism Occurs when the body's compensatory responses to hypothyroidism are overwhelmed by a precipitating factor Infection, medications, surgery, trauma, hypoglycemia, **failure to reinstate thyroid replacement therapy**

Answer 3

Myxedematous face: generalized puffiness, macroglossia, ptosis, periorbital edema Nonpitting edema of the lower extremities **Deterioration of mental status – confusion, psychosis, and rarely coma Hypothermia < 35.5°C (95.9°F)** Admission to the ICU Ventilatory, electrolyte, and hemodynamic support, thyroid replacement ## Footnote The patient does not need to be comatose to be diagnosed with myxedema coma

Answer 4

General term that refers to “inflammation of the thyroid gland” Encompasses several etiologies that present in different ways Autoimmune thyroiditis (Hashimoto thyroiditis) Painful subacute thyroiditis Each etiology has a specific pathologic mechanism

Answer 5

Also known as chronic lymphocytic thyroiditis **Most common form of thyroiditis** **Autoimmune** thyroid disease resulting in the destruction and failure of the thyroid gland Epidemiology: Age of onset is usually between 30-50 years More common in ♀>♂ Exact trigger is unknown, although genetic and environmental factors play a role Hashimoto Thyroiditis

Answer 6

Genetic risk factors: Associated with mutations in **HLA-DR3 and DR5 genes** Disease clusters found in families suggest genetic susceptibility **↑ Incidence in patients with Down's syndrome and Turner's syndrome**

Answer 7

Autoimmune destruction is initiated; progressive **depletion of thyroid epithelial cells** Thyroid cell destruction mediated by: **CD8+ cytotoxic cells Local production of cytokines** **Antibodies** made to **thyroglobulin (Tg) and thyroid peroxidase (TPO)**- only need one not both antibodies

Answer 8

Transient ↑ of thyroxine (T4) and triiodothyronine (T3) Compensatory ↓ thyroid-stimulating hormone (TSH) follows → T3/T4 stores gradually decline End result: **↑ TSH + hypothyroidism** (often permanent)

Answer 9

Increased risk of: Developing other autoimmune diseases B-cell lymphoma of the thyroid gland due to chronic inflammation Typically presents with a **triphasic clinical course**

Answer 10

Phases: 1. “Hashitoxicosis” - initial transient hyperthyroidism 2. Subclinical hypothyroidism 3. Overt hypothyroidism

Answer 11

+/- Goiter * Dry, coarse skin; alopecia; cool extremities Puffy face, hands, and feet (nonpitting edema/myxedema) Bradycardia

Answer 12

Fatigue, cold intolerance, weight gain Dry skin, hair loss Difficulty concentrating and poor memory Hoarse voice, impaired hearing Constipation Menstrual irregularities (menorrhagia, then oligomenorrhea or amenorrhea) Paresthesia

Answer 13

Thyroid hormone levels will differ in each phase: Hashitoxicosis: ↓ TSH + ↑ free T3/T4 Subclinical hypothyroidism: ↑ TSH + normal free T3/T4 Overt hypothyroidism: ↑ TSH + ↓ free T3/T4 ↑ Thyroid peroxidase antibody level (TPO Ab) – 90% of cases High levels of TPO Ab predicts progression to symptomatic hypothyroidism ↑ Thyroglobulin antibodies (Tg Ab) – 40% of cases

Answer 14

Differentiate between thyroiditis form multinodular goiter, thyroid nodules, or malignancy

Answer 15

low uptake → cold thyroid | checking for malignancy

Answer 16

If there is a dominant nodule or suspicion of malignancy

Answer 17

Radiologic diagnostic tool used to determine the **thyroid** function and pathology Uses radioactive iodine (I-123 or I-131) Thyroiditis versus other thyroid diseases): A: normal B: Graves' disease: diffuse increased uptake in both thyroid lobes C: toxic multinodular goiter: “hot” and “cold” areas of uneven uptake D: toxic adenoma: increased uptake in a single nodule with suppression of the surrounding thyroid **E: thyroiditis: decreased or absent uptake**

Answer 18

Antithyroid medication **should not** be used Nonspecific beta-blockers to block peripheral conversion of T4 → T3

Answer 19

Levothyroxine - synthetic form of T4 that is peripherally converted to T3 1.6 mcg/kg PO daily for young and healthy patients 25 mcg per day in the elderly Adjust dose by 12.5 or 25 mcg every 4-6 weeks until clinically euthyroid; may also reduce goiter size Goal: TSH level of 1-2 Absorption reduced by antacids, iron, calcium

Answer 20

Levothyroxine 25-50 mcg PO daily Adjust dose by 12.5 or 25 mcg every 4-6 weeks until clinically euthyroid

Answer 21

**Transient thyrotoxic state characterized by anterior neck pain** Often follows an upper respiratory viral infection → triggers an inflammatory destruction of thyroid follicles Most recover, but 1/3 evolve into overt hypothyroidism over a 10-year period ♀>♂

Answer 22

Neck pain in the area of the thyroid (**cardinal feature**) that may radiate to the jaw Diffuse thyroid enlargement (goiter) Dysphagia Increased sweating Tremor Weight loss Fever Tachycardia

Answer 23

Lasts 4-8 weeks ↓ TSH Initially ↑ free T4 and T3 (T4>T3 -transient hyperthyroidism is due to passive release of stored thyroid hormone) ↑ ESR and CRP Thyroid scan with radioactive iodine uptake **Low uptake of iodine**

Answer 24

Variable length ↑ TSH ↓ free T4 and T3

Answer 25

The thyroid gland spontaneously resumes normal thyroid hormone production after several months in most cases **Beta blockers** may be used for patients with significant hyperthyroid symptoms **Thyroid hormone supplementation** is only needed for patients who are symptomatic or have clear signs of hypothyroidism (levothyroxine)

Answer 26

First-line therapy options: **Aspirin** (acetylsalicylic acid) 2,600 mg/day in divided doses **Ibuprofen** 3,200 mg/day in divided doses If no improvement of neck pain after 4 days or patient has severe neck pain Corticosteroids 40 mg/day x 5-7 days, then slowly tapered over 30 days

Hypothyroid/thyroiditis Flashcards

(53 cards)