Hypothyroid[1].pptxjhbgjkgyylgyjfygiuguhiuhiugiu

vjhgjygljglug;ukhkugjgjygjyhgjygugbukhkuk;uk;ubkjhbkjbkjbkugkugkuguiuhihkuhkuhkhkuhkhbkubkgkgkuhkuhkihkhkihibkbkbkjbkbkjbjbjhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

1. HYPOT H YROIDISM NANDINI SAHA 122016101082

2. ETIOLOGY Deficient thyroid hormone secretion can be due to thyroid failure(PRIMARY HYPOTHYROIDISM). Pituitary or hypothalamus disease (SECONDARY HYPOTHYROIDISM). Transient hypothyroidism may occur in silent or subacute thyroiditis. Sub clinical (or mild) hypothyroidism is state of normal thyroid hormone levels and mild elevation of TSH. With higher TSH levels and low free T4 levels,symptoms become more readily apparent in clinical hypothyroidism. In areas of iodine sufficiency,autoimmune disease and iatrogenic causes are most common.

3. CLINICAL FEATURES Symptoms of hypothyroidism include :Lethargy,dry hair and skin,cold intolerance,hair loss,difficulty in concentrating,poor memory,constipation,mild weight gain with poor appetite,dyspnea,hoarse voice,muscle cramping and menorrhagia. Cardinal features on examination include: Bradycardia,mild diastolic hypertension,prolongation of relaxation phase of deep tendon reflexes and cool peripheral extremities. Goitre may be palpated,or thyroid may be atrophied and non palpable. Carpal tunnel syndrome may be present. Cardiomegaly may be present due to pericardial effusion. The most extreme presentation is dull,expressionless face,sparse hair,periorbital puffiness,large tongue and pale and cool skin. The condition may progress into a hypothermic,stuporous state (myxedema coma) with respiratory depression.

4. DIAGNOSIS Decreased serum T4 is common to all varieties of hypothyroidism. An elevated TSH is a sensitive marker of primary hypothyroidism. Thyroid peroxidase(TPO) antibodies are increased in patients with autoimmune mediated hypothyroidism. Elevated cholesterol,increased creatine phosphokinase,and anemia may be present. Bradycardia,low amplitude QRS complexes,and flattened or inverted T waves may be present on ECG.

5. ALGORITHM FOR DIAGNOSIS OF HYPOTHYROIDISM

6. CAUSES Primary : Autoimmune hypothyroidism-Hashimoto’s thyroiditis,atrophic thyroiditis. Iatrogenic-Iodine 131 treatment,subtotal or total thyroidectomy,external irradiation of neck for lymphoma or cancer. Drugs-iodine excess (including iodine containing contrast media and amiodarone),lithium,antithyroid drugs ,p-amino salicylic acid,interferon alpha other cytokines,aminoglutethimide. Congenital hypothyroidism -Absent or ectopic thyroid gland,dyshormonogenesis,TSH-R mutation. Iodine deficiency Infiltrative disorders-amyloidosis,sarcoidosis,hemochromatosis,scleroderma,cystinosis,Riedel’s thyroiditis.

7. Transient : Silent thyroiditis, including postpartum thyroiditis. Subacute thyroiditis Withdrawal of thyroxine treatment in individuals with an intact thyroid After Iodine 131 treatment or subtotal thyroidectomy for Graves’ disease.

8. Secondary : Hypopituitarism-tumours,pituitary surgery or irradiation,infiltrative disorders,Sheehan’s syndrome,trauma,genetic forms of combined pituitary hormone deficiencies. Isolated TSH deficiency or inactivity Bexarotene treatment Hypothalamic disease-tumours,trauma,infiltrative disorders,idiopathic.

9. TREATMENT Adult patients<60yrs without evidence of heart disease may be started on 50-100 micrograms of levothyroxine (T4) daily. In elderly or in patients with known CAD,the starting dose of levothyroxine is 12.5-25 micrograms/day The dose should be adjusted in 12.5 to 25 micrograms increments every 6-8 weeks on basis of TSH levels,until a normal TSH level is achieved. The usual daily replacement dose is 1.6 micrograms/kg/day. Women on levothyroxine replacement should have a TSH level checked as soon as pregnancy is diagnosed,as the replacement dose typically increases by 30-50% during pregnancy.

10. Failure to recognise and treat maternal hypothyroidism may adversely affect fetal neural development. Therapy for myxedema coma should include levothyroxine (200 micrograms) and liothyronine (25 micrograms) asa single IV bolus followed by daily treatment with levothyroxine (50-100 micrograms/day) and liothyronine(10 micrograms q8hr),along with hydrocortisone (50mg q6hr)for impaired adrenal reserve,ventilatory support,space blankets and therapy of precipitating factors.

11. Thank You