5 % OF THE WORLD POPULATIONSUFFERS FROM THYROID DISEASE
CONGENITAL HYPOTHYRIODISM IS ONE OFTHE MOST COMMON CAUSES OF PREVENTABLE MENTAL RETARDATION WORLD-WIDE
20 MILLION PEOPLE IN THE WORLD HAVE VARIOUS DEGREES OF BRAIN DAMAGECAUSED BY IODINE DEFICIENCY IN UTERO
MEDICAL MANAGEMENTOF THYROID DISEASE By- MOHAMMAD SADIQ III YR. M.B.B.S. M.M.C.R.I.
THYROID DISORDERSThe conditions we will deal with here are: 1. Thyrotoxicosis 3. Hypothyroidism 5. Medical Emergencies > Myxoedema coma > Thyrotoxic crisis • Congenital Hypothyroidism (Cretinism) • Thyroid Disease complicating pregnancy
THYROID DISORDERS MEDICAL MANAGEMENTProper management is based upon: 1. Proper Clinical Diagnosis 3. Laboratory Evaluation 5. Treatment 7. Monitoring of patient
THYROTOXICOSIS INTRODUCTION“Defined as the state of thyroid hormone excess & isnot synonymous with hyperthyroidism which is the resultof excessive thyroid function” Top 2 causes are: Grave’s Disease (76%) Multi Nodular Goitre (14%)
HYPOTHYROIDISM ETIOPATHOGENESISIodine deficiency remains the leading cause World-wide. In areas of iodine sufficiency the causes are: • Hashimoto’s thyroiditis • Spontaneous Atrophic thyroiditis • Iatrogenic causes
HYPOTHYROIDISM PRESENTING COMPLAINTHASHIMOTO’S ATROPHICTHYROIDITIS: THYROIDITIS:• Symptoms of Goitre • Symptoms ofmore than that of Hypothyroidism moreHypothyroidism. than that of Goitre
THYROTOXICOSIS MANAGEMENT OF ATRIAL FIBRILLATION• Generally control of serum T4 causes a return to sinus rhythm.• Drugs provide symptomatic relief. • VR responds little to Digoxin. • Good response to addition of β - blockers. • CARDIOVERSION to revert to sinus rhythm. (Only after TSH/T4 ↔ ) • Anti coagulation with Warfarin / Aspirin.
THYROTOXICOSIS MEDICAL MANAGEMENT2. RADIOACTIVE I131 :MOA: > Destroys functioning thyroid cells > Inhibits their ability to replicateDose: 180-370 MBq (5-10mCi) orally (Dep. on goitre size)• 4-6 weeks to be effective (long lag period)∀ β-blockers control symptoms in lag period.• Severe cases: Carbimazole within 48 hrs of I131
THYROTOXICOSIS MEDICAL MANAGEMENT3. Role of β-blockers: ONLY SYMPTOMATIC RELIEF (within 12-24 h) Propronolol: 160 mg/day Nadolol: 40-80 mg/dayT3 toxicosis : I131(555-110Mbq), Hemithyroidectomy
THYROTOXICOSIS EFFECT OF TREATMENTBEFORE AFTER
THYROTOXICOSIS EFFECT OF TREATMENTBEFORE AFTER
HYPOTHYROIDISM MEDICAL MANAGEMENT Life long therapy with Levothyroxine (T4) is the sheet anchor Start slowly with 50µg/day OD – 3 weeks Then ↑ to 100µg/day OD – 3 weeks Finally ↑ to 150µg/day ODHypothyroidism following Grave’s Disease → 75-125µg/day OD Improvement takes 2-3 weeks
HYPOTHYROIDISM MEDICAL MANAGEMENTRATIONALE IN USING T4 IN HASHIMOTO’S:2. Treatment of Hypothyroidism3. Goitre shrinkage T4 vs. T3 – Why T4? T3 in high doses causes: • Angina • Arrythmias • Heart Failure
HYPOTHYROIDISM MONITORING THERAPY• Correct dose of drug: Restores serum TSH to lower part of reference range when T4 is ↔ / slightly ↑.• Advise & reinforce need for regular medication.• TFT screening every 1-2 years. ↑ T4 & ↑ TSH - ?
HYPOTHYROIDISM EFFECT OF TREATMENT BEFORE AFTER
HYPOTHYROIDISM EFFECT OF TREATMENTBEFORE AFTER
THYROID DISORDERS INVESTIGATIONS Disorder TSH Free T4 Free T3 (0.3-3.5 mU/L) (10-25 pmol/L) (3.5-7.5 pmol/L)Thyrotoxicosis ↓↓ ↑ ↑ (<0.05mU/L) Primary ↑ (>10 mU/L) ↓ or ↔/↓Hypothyroidism low normalTSH deficiency Low normal / ↓ or ↔/↓ sub normal low normal T3 Toxicosis ↓↓ ↔ ↑ (<0.05 mU/L)Compensated Slightly ↑ ↔ ↔Euthyroidism (5-10 mU/L)
MEDICAL EMERGENCIES 2 Situations : 1. HYPERTHYROID CRISIS (= Thyrotoxic crisis / Thyroid storm) 4. MYXOEDEMA COMA
HYPERTHYROID CRISIS MANAGEMENT• Rehydrated• Broad spectrum antibiotic• Propronolol 80 mg 6th hrly orally / 1-5 mg 6th hrly i.v.• Large doses of Propyl thiouracil 600 mg loading dose & 200-300 mg every 6 hrs orally/NGT/PR is the DOC.• Stable Iodine 1 hr later.• Saturated sol of KI / Na iopodate 500 mg/d orally restores normal levels of T3 within 48-72 hrs.• Others: Glucocorticoids, Cooling, Oxygen
MYXOEDEMA COMA CLINICAL PICTURE∀ ↓ level of consciousness usually in an elderly patient who appears myxoematous• Body temperature as low as 25oC• Convulsions• CSF pressure & proteins ↑• Mortality rate around 50% (EARLY DETECTION is essential)
MYXOEDEMA COMA MANAGEMENT TREATMENT must begin IMMEDIATELY• Triiodothyronine i.v. bolus 20µg followed by 20µg 8th hourly till there is sustained clinical improvement.• Liothyronine (T3) i.v. / NGT 10-25 µg 8-12th hourly (v. rapid)• T3 (25µg) + T4 (200µg) as a single initial i.v. bolus followed by daily trt. with Levothyroxine 50-100 µg 8th hrly. Others: Slow rewarming (if <30oC), Cautious use of i.v. fluids, Broad Spectrum antibiotics, High flow oxygen, Assisted ventilation
CRETINISM “Children who are hypothyroid from birth / before are called cretins.” WHO IS A CRETIN?“What should have been an angel of Godhas been a pariah of nature just for the wantof a little iodine in mother’s blood.”
CRETINISMGUESS MY AGE? 22 yr. old female Pot belly Umbilical hernia Coarse facial features Supra clavicular pad of fat
CRETINISMGUESS MY AGE? 17 yr. old female Congenital hypothyroidism Large ears Enlarged protruded tongue Wide set eyes Depressed nasal bridge Short limbs Estim. bone age : 9 months
CRETINISM MANAGEMENT Monitoring of thyroid status of mother is important If mother is… Euthyroid Hypothyroid• Dev. normal until birth • Iodine def. is commonest cause• Manifests at birth • MR is more severe• Treatment started at birth • Less responsive to trt. has good prognosis • Deaf mutism & rigidity + Intake of iodised salt has ↓ this
CRETINISM TREATMENT Sodium Levothyroxine 100µg tab is the DOCDose: Neonates: 10-15 µg/kg/day Older children: 4-8 µg/kg/dayNeonates & Children < 1yr.: INITIATE trt. on DIAGNOSIS DON’T WAIT for INVESTIGATIONS
CRETINISM MONITORING1. Assess Clinical Milestones2. Periodic TFT3. Radiological estimation of bone age annually Antenatal screening: > Regular TFT – mother > Foetus USG
THYROID DISEASECOMPLICATING PREGNANCY HYPERTHYROIDISM - MANAGEMENT Carbimazole is the drug used • Crosses placenta and also treats foetus • Imp to use the smallest dose possible • Review every 4 weeks • Discontinue Carbimazole 4 weeks before EDD Radioactive Iodine is C/I If Hyperthyroid mother wants to feed?
THYROID DISEASECOMPLICATING PREGNANCY HYPOTHYROIDISM - MANAGEMENT Why treat? On the basis of serum TSH measurements most pregnant women with primary hypothyroidism require an additional 50µg thyroxine to their usual dose ( TBG ↑ in pregnancy).
MEDICAL MANAGEMENT OF THYROID DISORDERS CONCLUSION1. Thyroid disease may have a variable clinical presentation.Hence, it is very essential to have a high degree of caution beforedeclaring a patient euthyroid. It is better to do a TFT in allsuspected cases. The cost of the TFT is noting compared to thedire consequences of a missed diagnosis.7. Treatment must be started immediately in all suspected casesof thyroid storm/myxoedema coma/cretinism as a delay in treatmentmight be fatal to the patient or may land the child in permanentmental retardation.