1 / 34

D- Interpreting Thyroid Function Tests

D- Interpreting Thyroid Function Tests. Pt Info: CC: palpitations 82 y/o F presents with hyperactivity, sweating, palpitations, wt loss, insomnia, moist skin, fine hair, irregular menses, diarrhea PE: tachy, elevated SBP, damp skin, lid lag, hyperreflexive DTR

braden
Download Presentation

D- Interpreting Thyroid Function Tests

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. D- Interpreting Thyroid Function Tests

  2. Pt Info: • CC: palpitations • 82 y/o F presents with hyperactivity, sweating, palpitations, wt loss, insomnia, moist skin, fine hair, irregular menses, diarrhea • PE: tachy, elevated SBP, damp skin, lid lag, hyperreflexive DTR • Labs: CBC wnl, BMP wnl, TSH <0.01 (L), T4 4.1 (H), T3 wnl

  3. Objectives • Pathophysiology • Thyrotoxicosis • Hypothyroid

  4. Hormone Regulation • TRH à TSH • iodine uptake, organification • synthesis & release of thyroid hormone • T4/T3 Regulate: • basal metabolism, thermogenesis, lipogenesis • fetal CNS development

  5. Thyroid Hormones • Triiodothyronine (T3) • 80% in Periphery • Liver/kidney remove iodine from T4 • Regulate Thyroid Hormone-dependent genes • t1/2: 1-1.5 days • Thyroxine (T4) • Thyroid gland • t1/2: 8 days • T4 à T3 • Decreased: • Meds: propranolol, PTU, corticosteroids, amiodarone • Illness: cytokine mediated

  6. Binding Proteins • T4/T3 99% protein bound • Prevents excess tissue uptake • Maintains accessible reserve • Thyroxine-binding globulin (TBG) - 70% • Inc: E2, 5-FU, Methadone, Tamoxifen • Dec: Androgens, Corticosteroids, Niacin • Albumin – 15-20% • Transthyretin – 10-15%

  7. LOW = Hyper Check free T3/T4 NL = No further Testing HIGH = Hypo Check free T4 TSH TFTs

  8. Grave’s Disease • Toxic Adenoma • Toxic Multinodular Goiter • Thyroiditis • Exogenous • TSH Mediated FunctionalDisorders • Hashimoto’s Disease • Post-op/Post-ablative • I deficiency Hypothyroidism Thyrotoxicosis

  9. Thyrotoxicosis • Thyroid excess from any cause: • Increased Synthesis • Damaged Gland • Exogenous Intake • RAIU • High (>30%): Hyperfunction • NL (10-30%): Euthyroid • Low (<10%): Thyroiditis, I excess, Amiodarone

  10. Symptoms • Other: • Pregnancy-related problems • Arthralgias • Skin: hives, itching, vitiligo • Hair loss • Finger/nail changes • Eye: bulging, dry, pain • Depression, irrational anger Increased Metabolism: • Weight loss, Dec appetite • Warm, sweating, thirst, fever • Tachycardia, Arrhythmia, Palpitations • Diarrhea • Fatigue, Exhaustion • Goiter • Difficulty concentrating • Panic and anxiety • Hyperreflexia, Tremors • Insomnia

  11. Thyrotoxicosis • Increased Synthesis • Damaged Gland • Exogenous Intake

  12. Increased Synthesis: Hyperthyroidism • High T4 & Low TSH • Increased T4/T3 release: • Grave’s • Toxic MNG • Toxic Adenoma • High RAIU

  13. Grave’s Disease • Most common cause in US • AutoAb against TSH receptor • Diffuse Goiter, Thyrotoxicosis, High RAIU • Thyroid Scan: Increased activity • Ophthalmopathy, Dermopathy, Acropathy

  14. Grave’s Disease - treatment • Medication: 50% remission @ 1 year • Methimazole • PTU • BB while toxic • Radioactive Iodine Ablation • Not for pts with severe ophthalmopathy • Surgical Removal

  15. Toxic Multinodular Goiter • Sporadic Goiter à Multinodular Euthyroid à Subclinical à Overt Thyrotoxicosis • Increased RAIU (autonomous production) • Rest of Gland suppressed • Treatment: Radioactive Iodine

  16. Toxic Adenoma • HOT Nodule: Autonomous function • Activating Mutation of TSH Receptor • Size = Hormone production • >3 cm • Treatment: • Hemithyroidectomy • Radioactive Iodine

  17. Thyrotoxicosis • Increased Synthesis • Damaged Gland • Exogenous Intake

  18. Damaged Gland • Low RAIU • Subacute Thyroiditis: BB & NSAIDs • Firm & painful gland • Post-viral • Drug-Induced • Amiodarone, Lithium, α-IFN, IL-2 • Postpartum Thyroiditis

  19. Amiodarone-Induced • 3% of patients in US • Type 1: high iodine content (JodBasedow) • Pre-existing thyroid autonomy • High RAIU • Treatment: methimazole • Type 2: direct toxic effect • No Pre-existing thyroid autonomy • Low RAIU, Inc Inflammation • Treatment: Prednisone, NSAIDs

  20. Thyrotoxicosis • Increased Synthesis • Damaged Gland • Exogenous Intake

  21. Surreptitious Intake • Low TSH • Low RAIU • Low TG level

  22. Thyroid Storm • Iatrogenic • Radioiodine therapy, Contrast dyes • Abrupt cessation of Antithyroid drugs • Surgery • Acute Nonthyroidal Illness • Stroke, PE, DKA, Trauma, Infection

  23. Thyroid Storm - treatment

  24. Subclinical Thyrotoxicosis • Low TSH & High NL T4 • Complications • Arrhythmia, Osteoporosis • esp >65y/o with TSH <0.1 mU/L

  25. Grave’s Disease • Toxic Adenoma • Toxic Multinodular Goiter • Thyroiditis • Exogenous • TSH Mediated FunctionalDisorders • Hashimoto’s Disease • Post-op/Post-ablative • I deficiency Hypothyroidism Thyrotoxicosis

  26. Hypothyroidism • Low T4 & High TSH • More common than Thyrotoxicosis • Treatment: Synthroid - goal TSH 1-2 mU/L

  27. Symptoms • Accumulation of Matrix Substance: • Skin: coarse/dry, scaly • Hair: coarse/dry, brittle, loss • Hoarseness • Edema of eyes and face • Other: • Arthralgias • Irregular menstrual cycles • Depression Slow Metabolism: • Weight Gain • Constipation • Hypothermia/Cold Intolerance • Fatigued, Lethargy • Slow Movements/speech • Delayed DTRs • Bradycardia

  28. HIGH = Not Enough INC Dose LOW = Too Much DEC Dose NL = Continue Dose TSH Monitoring Replacement

  29. Medication Controversy • ? Generic Synthroid • Not all bioequivalent when FDA approved • ? T3 • 1999: improved mood & psych testing with combo therapy • Four subsequent studies refuted

  30. Hashimoto’s • Most common cause in North America • Positive anti-TPO Ab • Increase Autoimmune Endocrinopathy • Addison’s, DM1, Premature ovarian failure • No further w/u

  31. Myxedema Coma • Obtundation, Hypothermia • CV Changes: • Dec HR, Contractility, SBP, CO • Inc SVR, DBP • Pericardial Effusion • Precipitant: Infection, trauma, cold, sedative

  32. Myxedema Coma - treatment • IV Levothroxine replacement • Corticosteroids – adrenal insufficiency • MV – CO2 retention, hypoxia • Treat precipitating cause

  33. Subclinical Hypothyroidism • High TSH & Low NL T4 • Most have Hashimoto’s • Systemic symptoms, elevated LDL, Cardiac changes

  34. Objectives • Pathophysiology • Thyrotoxicosis • Hypothyroid

More Related