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Psychological: insomnia, anxiety, irritability, emotional lability, panic attacks
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- Features unique to Grave’s
- Hypothyroidism
Psychological: insomnia, anxiety, irritability, emotional lability, panic attacksheat intolerance Autonomic: sweating, tremor, hyperreflexia, diarrhea Metabolism: weight loss, weight gain from increased appetite (less common) proximal muscle weakness, menstrual dysfunction (oligomenorrhea, amenorrhea)
(Note: Graves’ ophthalmopathy tends to worsen at 12-18 months, then stabilize, but can worsen in spite of thyroid status) Skin: fine, smooth, velvety, moist (warm), onycholysis (brittle nails) Reproductive: oligomenorrhea, reduced sperm count, impotence, gynecomastia Diffuse goiter; bruit over thyroid Note: too much thyroid can increase bone turnover and risk of fracture / use Fosamax type agents in women being treated with thyroid hormone for thyroid cancer Note: elderly hyperthyroid patients may have only subtle signs (weight loss, tachycardia, fine skin, brittle nails) called apathetic hyperthyroidism (lethargy rather than hyperkinetic) / may not have enlarged thyroid / look for unexplained CHF, worsening of angina, or new-onset atrial fibrillation resistant to treatment Labs: increased free T4 (or FTI), decreased TSH (should be undetectable in Graves’), increased T3 anti-thyroid Ab bind TSH receptors (activate AC) increased I-123 uptake (because there’s still some TSH around) ?elevated ferritin
TSH-like-antibodies (think autoimmune disease) / can cross placenta neonatal thyrotoxicosis Genetics: HLA-B8 and HLA-DR3 in Caucasians with Graves’ disease.
Features unique to Grave’s: (mostly by activated fibroblasts)Infiltrative ophthalmopathy: exophthalmos [pic], lid retraction, lid lag (sclera can be seen above iris as patient looks downward) Infiltrative dermopathy: pretibial myxedema (raised, hyperpigmented areas involving the pretibial region and the feet, which is actually rare; orange peel texture papules) Thyroid acropachy: clubbing of fingers associated with periosteal new bone formation in other skeletal areas Diagnosis: radioactive uptake scan will reveal diffuse increased uptake of iodine Treatment: PTU (50-100 mg PO q8h) or methimazole (10-20 mg PO q8h or 30-60 mg/day single dose) Propranolol: as needed for sympathetic symptoms (tachycardia, tremor, etc.) 20-40 mg PO q6h (taper upward to control symptoms) Radioactive (I131) 1st line for men and women over 20 yrs and younger pts who do not achieve remission by 1 yr of meds (many pts have difficult time with meds and fluctuating symptoms) / will need to be on replacement thyroxine after / contraindicated during pregnancy (can cause fetal hypothyroidism) Surgery (subtotal thyroidectomy) pregnant patient refractory to (or does not tolerate) low-dose PTU / obstructive goiter complications: hypothyroidism (30% by 10 yrs), hypoparathyroidism, damage to recurrent laryngeal nerve (this is unfortunately a common occurrence) Graves’ ophthalmopathy (in severe cases) high-dose steroids, external radiation, or orbital decompression / methylcellulose eye drops (e.g., Tears Naturale) are useful for dry eyes Course: 20-40% can remain euthyroid for long periods after treatment with PTU et al (15% get autoimmune hypothyroidism about 10-15 yrs later) Toxic multinodular goiter Usu. women > 55 yrs Presentation: usu. insidious and symptoms (tachycardia, tremor, heat intolerance) may be masked by manifestations of coexisting diseases (e.g., a patient with ASHD may have CHF secondary to atrial fibrillation with a fast ventricular response) Diagnosis: thyroid scan demonstrates heterogeneous increased uptake Treatment: radioactive iodine (I131) after initiation of B-blockers or surgery Toxic adenoma (Plummer Disease) (see thyroid neoplasms) Note: “hot nodule” is almost never malignant Diagnosis: thyroid scan demonstrates increased uptake (“flag of Japan” pattern), usu. > 3 cm Treatment: surgical removal of adenoma is preferred in young hyperthyroid patients and patients with very large adenoma / all other pts get I131 radioablation Thyroid Storm Causes: major stress (e.g., infection, MI, surgery, DKA) in undiagnosed hyperthyroidism, inadequate replacement therapy in a hyperthyroid patient Presentation: fever ( > 100 ° F), marked anxiety and agitation, psychosis, hyperhidrosis, heat intolerance, marked weakness/muscle wasting, tachyarrhythmias, palpitations, diarrhea, nausea, vomiting / elderly patients may have a combination of tachycardia, CHF, and mental status changes Exam: goiter, tremor, tachycardia (>140), fever (104-106), moist skin, vomiting, diarrhea, lid lag, lid retraction, proptosis, altered mental status (psychosis, delirium, coma, seizures), other evidence of precipitating factors (infection or trauma) Labs: increased free T4 or FTI, decreased TSH / always rule out sepsis Treatment: start empirically if suspected (do not wait for labs) Block synthesis PTU 30O-600 mg PO or NG tube, then 150-300 mg q6h If GI obstruction or vomiting, can give methimazole (Tapazole), 80 to 100 mg PR followed by 30 mg PR q8h Block release (of T4 that has already been made) Iodide: sodium iodide, 250 mg IV q6h; potassium iodide (SSKI), 5 gtt PO q8h; or Lugol’s solution, 10 gtt q8h. Give PTU 1 hr before iodide to prevent thyroid from oxidizing iodide to iodine (which would make more hormone) Corticosteroids: dexamethasone, 2 mg IV q6h, or hydrocortisone, 100 mg IV q6h (~48 hrs) / inhibits release, impairs peripheral conversion (T4 to T3), covers for cortisol deficiency, suppresses effects of T4/T3 Supportive Propranolol: 80 to 120 mg PO q4-6h; in acute situations propranolol may also be given IV 1 mg/min for 2 to 10 min under continuous ECG and blood pressure monitoring / can use cardioselective agents in patients with bronchospasm / Anticipate increasing rate control (digoxin may not work as normal in this case) for patients prone to AF Acetaminophen, 300 to 600 mg q4h, or cooling blanket if necessary (do not use ASA as it displaces thyroid hormone from TBG) FEN (add glucose and multivitamins) Blood/Urine cultures, may need IV antibiotics if infection suspected Hypothyroidism2% of women / 0.2% of men / > 60 years (6% of women / 2.5% of men) Primary hypothyroidism (95% of cases) (problem with thyroid gland) Hashimoto’s thyroiditis (chronic lymphocytic thyroiditis); 1st in US ( > 8 yrs) Previous radioactive I- therapy or surgical thyroidectomy; 2nd in US Idiopathic myxedema (possibly a nongoitrous form of Hashimoto’s thyroiditis) Subacute thyroiditis Iodine deficiency/excess – most common worldwide Drugs (lithium, PAS, sulfonamides, phenylbutazone, amiodarone, thiourea) Radiation therapy of the neck (usually for malignant disease) Congenital (approximately 1:4000) Hypothyroidism of pregnancy Secondary hypothyroidism (pituitary problem) pituitary dysfunction, postpartum necrosis, neoplasm, infiltrative disease causing low TSH Diagnosis: can do TRH stimulation test to distinguish secondary/tertiary (note: most postpartum thyroiditis cases recover in 3-6 months so watching/waiting can be viable approach) Tertiary hypothyroidism hypothalamus/TRH deficiency (granuloma, neoplasm, or irradiation) tissue resistance to thyroid hormone (rare)
fatigue, lethargy, weakness, constipation, weight gain (usually < 15 Ib) muscle weakness, muscle cramps, arthralgias, carpal tunnel cold intolerance CNS (depression, irritability, mental slowing dementia in elderly) slow speech with hoarse voice (myxedema of vocal cords), transfer dysphagia hyperlipidemia Hashimoto’s ataxia (can happen any time/later on) oligomenorrhea, galactorrhea (in association with prolactinoma) Exam: Skin: dry, coarse, thick, cool, sallow (yellow color caused by carotenemia); nonpitting edema in eyelids/hands (subcutaneous deposition of hydrophilic mucopolysaccharide leads to myxedema syndrome in severe, prolonged form Hair: brittle and coarse, loss of outer third of eyebrows Face: dulled expression, thick tongue, and thick slow-moving lips Cretinism: pot-bellied, puffy face, protuberant tongue Neck: thyroid gland +/- palpable (depends on cause of hypothyroidism) Toxic multinodular goiter may resemble carcinoma / may be associated with hyperprolactinemia Diffuse non-toxic (simple) goiter Endemic: iodine deficiency / goitrogens in foods Sporadic: young females / defects in T4 production / compensatory thyroid hypertrophy CV: distant heart sounds (pericardial effusion may be present), bradycardia ↓ intravascular volume, ↓ cardiac output, ↓ HR, ↑ catecholamines, ↑ PVR, ↑ HTN 20-40% get ↑ systemic HTN in spite of decreased cardiac output (HTN is diastolic with diminished pulse pressure) GI: non-mechanical obstruction (ileus) Musculoskeletal: stiffness, weakness CNS: delayed relaxation phase (return phase) of DTR, cerebellar ataxia, hearing impairment, poor memory, peripheral neuropathies/paresthesias, carpal tunnel Autonomic: hypothermia part of myxedema coma (medical emergency, requires IV thyroxine 300-500 mcg bolus then daily IV doses (also give steroids, IV fluids, rewarm patient slowly to not precipitate cardiac arrhythmias) Complications (the cardiac ones are not all intuitive at face value—just know the consequences) (+) periorbital edema and nonpitting edema of hands, feet (interstitial ↑ GAG’s and H2O) Laboratory results Decreased free T4 or FTI ↑TSH (may be normal with 2o or 3o hypothyroidism or is on dopamine/corticosteroids or with severe illness) ↑ LDL and ↑ TG, ↑ LDH, ALT, AST, and MM band of CPK Decreased Hgb/Hct, hyponatremia ↑ antimicrosomal and antithyroglobulin antibody titers (seen in Hashimoto’s) Treatment L-thyroxine (Synthroid) / 1.6 ug/kg / Sx should improve within 24 hrs Dose depends on age/severity / may increase q 4-6 wks (depends on response) TSH takes 6-8 wks to reflect dose adjustments Decreased dose for elderly and CAD (higher doses can precipitate angina) Low and slow with CAD, ex. 25 mcg x 2 wks then 37.5 mcg x 2 wks then 50 mcg x 6 weeks then recheck TSH Maintain TSH (0.5 to 3) / can measure FTI with central disorders (upper ½ of normal range) Download 3.95 Mb. Share with your friends:
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