Thyroid Disorders Lecture Powerpoint Flashcards
Thyroid disease epidemiology
- Most autoimmune
- Women>men
- Familial predisposition
- Radiation exposure risk
Drug effects on the thyroid
- Estrogen therapy increases thyroid binding and thus may require increased dosing of thyroid hormone to maintain free hormone levels
- Biotin in popular supplements can interfere with lab testing (hold 48 hrs before testing)
- supplements such as antacids can prevent absorption of thyroid hormone
Differential for hyperthyroidism causes (5)
- Graves disease
- Toxic multinodular goiter
- Toxic adenoma
- Subacute thyroiditis
- Iatrogenic origin
Common presentation of hyperthyroidism (4)
- Sweating, tremor, palpitations
- widened pulse pressure and tachycardia
- proximal muscle weakness
- lid lag
Graves disease
Most common hyperthyroid disease onset of 20-50 years of age where an individual has developed autoantibodies for the TSH receptor at the thyroid causing excessive thyroid activity
Graves opthalmopathy
Immunologic mediated accumulation of extracellular water and ground substance that only occurs in about 20% of patients with graves disease unless they smoke which greatly increases risk, can result in diplopia or vision loss (optic nerve can stretch out causing everything to get green hue)
Lab results (TSH, free T3/4, thyrotropin receptor antibody test) in Graves disease
- TSH low
- T3/4 elevated
- Positive thyrotropin receptor antibody test
Hyperthyroidism from Graves disease treatment options (5) and ADR (1)
- Antithyroid drugs tapazole and PTU (block production of thyroid hormone), B blockers to control side effects, irradiation therapy, surgery
- Agranulocytosis (leukopenia)
Why is tapazole preferred to PTU for treatment of hyperthyroidism?
-It is not as hepatotoxic, but preference is reversed in pregnancy
Hyperthyroidism from Graves disease opthalmoapthy best and worst treatment options
- Antithyroid drugs tapazole and PTU are best
- Irradiation therapy is the worst
Subacute thyroiditis presentation (4)
- One week onset palpitations, tremor, sweating
- post URI onset
- Widened pulse pressure
- Can have tender thyroid
Subacute thyroiditis progression
- Initial phase of hyperthyroidism from healthy stores of thyroid hormone being released due to viral mediation
- Later transient phase of hypothyroidism
- Total resolution by 2-3 months
Subacute thyroiditis lab evaluation
Varies by phase
Subacute thyroiditis treatment options (4)
- Analgesics/NSAIDs
- B blocker in hyperthyroid phase
- thyroid hormone if hypothyroid phase
- Self limiting and does not return
Presentation of new onset of afib in elderly indicates need for…
….thyroid studies
Subclinical hyperthyroidism
A low serum TSH with normal free T4 and T3 with usually few or no symptoms of hyperthyroidism often with variable natural history and reversion to normal TSH within a year
Findings in subclinical hyperthyroidism that warrant further management (3)
- Change in bone mineral density
- Increased frequency of afib
- Reduced exercise tolerance
Subclinical hyperthyroidism management
Varies depending on patient
Hypothyroidism presenting symptoms (6)
- Fatigue
- Weight gain
- Cold intolerance
- Hypertension
- Edema
- delay in DTR
Peroxidase antibody
Test for hypothyroidism, if positive usually indicates hashimoto’s hypothyroidism
Hypothyroidism can be brought on by ___ or ___ iodine
excess, shortage
Hypothyroidism lab evaluation
- Elevated TSH
- Free T4/3 is low
Hypothyroidism treatment options (1)
-Synthroid (L thyroxine)
Subclinical hypothyroidism
Normal free T4 and 3 with slightly elevated TSH, diagnosis based on test results as clinical symptoms and signs are nonspecific, usually etiology is from hashimoto’s or prior ablative therapy, can become overt if not treated when TSH >10mU/L or other condition present, otherwise monitored
