Unit_10_Thyroid_Additional_pictures_and_information.pptx

Thyroid

1. Thyroid Disorders

2. Thyroid Gland Produces, stores, and releases metabolically active hormones Maintains metabolic stability Maintains growth and development Maintains body temperature and energy use

3. Thyroid Gland

4. Thyroid Hormones

5. Thyroid Hormones

6. Thyroid Hormones

7. Hypothalamus-Pituitary-Thyroid axis Hypothalamus Anterior Pituitary Gland Thyroid Gland Target Organs TRH TSH T3/T4 − − − T3/T4 binds to thyroid hormone receptors which regulates the transcription of genes ⊕ ⊕ ⊕

8. ↑FT4/ ↑FT3 + Low TSH Normal TSH Range FT4 w/in range Low FT4 + Elevated TSH FT4 w/in range + TPOab Overt Hyperthyroidism Overt Hypothyroidism Subclinical Hyperthyroidism Subclinical Hypothyroidism 1 4.5 10 100 0.4 0.1 0.01 TSH μU/L TSH and Spectrum of Thyroid Disorders

9. Hyperthyroidism

10. Clinical Presentation

11. Clinical Presentation

12. Hypothyroidism

13. Clinical Presentation

14. Subclinical Thyroid Disease Controversial on when to treat Patients have few to no symptoms of thyroid dysfunction Subclinical Hypothyroid TSH >4.5 mIU/L Free T4 =WNL (0.8-1.5 ng/dL) Subclinical Hyperthyroid TSH below the reference range Free T4 and T3 = WNL

15. Subclinical Thyroid Disease Subclinical Hypothyroidism Typically do not treat Consider treatment if Pregnant or considering pregnancy TSH >7-10 mIU/L Increased risk for CHF in elderly Increased risk in developing hypothyroid Elderly Clinical sxs present Subclinical Hyperthyroidism Typically treat if patient has TSH <0.1 mIU/L and any of the following Heart disease (CHF, A-fib, arrhythmias) Osteoporosis Age >60 Typically monitor patient if TSH 0.1-0.45 mIU/L

16. Euthyroid Sick Syndrome Nonthyroidal Illness Acute and Chronic Illness can decrease T3 concentrations TSH will not change Decrease in T4 to T3 conversion Possible body adaptation Do not treat unless true hyperthyroidism is present

17. Myxedema Coma End stage of long-standing, uncorrected hypothyroidism Clinical s/sxs Hypothermia Advanced hypothyroid symptoms Altered sensorium Delirium to coma High Mortality

18. Myxedema Coma Treatment Thyroxine 300-500 mcg IV bolus 75-100 mcg IV daily Hydrocortisone 100mg IV q8h until adrenal suppression is ruled out Supportive Therapy Maintain ventilation, euglycemia, BP, and body temperature

19. Thyroid Storm Life-threatening medical emergency Severe thyrotoxicosis High fever Tachycardia Tachypnea Dehydration Delirium Coma N/V/D Precipitating Factors Infection Trauma Surgery RAI treatment Withdrawal of antithyroid drugs Occurs at any age Average duration 72 hours with treatment Mortality 20%

20. Thyroid Storm Therapeutic Measures Suppression of thyroid hormone formation and secretion Antiadrenergic activity Corticosteroids Treatment of complications or coexisting factors that may have precipitated the storm PTU is preferred 900-1200mg/day Can be given rectally or through NG tube Iodides Give after PTU Propranolol 40-80mg q6h Esmolol if cardiac disease or risk of pulmonary disease or cardiac failure No NSAIDS or aspirin APAP to treat fever