Thyrotoxicosis
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Transcript of Thyrotoxicosis
THYROTOXICOSIS
Dr Mukhilesh R M.S.,
Hyperthyroidism
This disease result from an excess of circulating thyroid hormone.
Its very important to distinguish disorders:
1.Cause excess production of hormone - characterized by increasing in radioactive iodine uptake.
2.An other condition which release stored hormone such as thyroiditis.
Hyperthyroidism VS Thyrotoxicosis
Not all manifestations are related to elevated thyroid hormones.
Clinical types
Primary thyrotoxicosis – Grave’s Disease
Secondary Thyrotoxicosis – Plummer’s Disease
Toxic nodule Rare causes for hyperthyroidism
Grave’s Disease
Diffuse vascular goitre. Symptom appears with
goitre Younger women with
eye signs TSH-R Abs –
hypertrophy and hyperplasia of the thyroid tissue.
Toxic Nodular goitre
Long standing nodular goitre Middle aged women
infrequently associated with eye signs
Internodular tissue is the active region
Rarely , autonomous nodules.
Toxic nodule
Overactive nodule part of generalised nodularity or true toxic adenoma.
Not related to TSH-R Abs. Normal thyroid tissue is suppressed
and inactive.
Histology
SCALLOPED PATTERN
THYROXINE IS THE KEY FOR
ADRENALINE TO ACT ON THE CELL
Clinical Features
Primary VS Secondary Thyrotoxicosis
Features Primary Thyrotoxicosis
Secondary Thyrotoxicosis
Goitre Firm , diffuse and vascular / Bruit
Nodular
Hyperthyroidism
Severe Not severe
CVS Rare Most severe
Ophthalmic Features
More common Lid lag and spasm
Cardiovascular Symptoms
Secondary thyrotoxicosis
Multiple extrasystoles Paroxysmal atrial fibrillations Paroxysmal atrial tachycardia Paroxysmal atrial fibrillations.
Eye Signs
Primary thyroosicosis Lid spasm – sympathetic overactivity Exophthalmus Joffrey’s and VonGraffe’s sign Mobieus Sign Auto immune etiology – glycosamino
glycans deposition Weakness of extraoccular muscle Pappilloedema and corneal ulcers
Contd..
Malignant exophthtalmus – eyes may be destroyed.
Treatment of malignant exophthalmus
Rx Control of hyperthyroidism Sleeping propped up position Lateral tarsoraphy Prednisone Intraorbital steroid are to be avoided. Thryoid ablation with radio iodine
worsens the malignant exophthalmus Orbital decompression.
Thyroid dermopathy
Hyaluranic acid – dermis and subcutaneous tissue.
Rx – topical steroids
Diagnosis of thyrotoxicosis
Clinical features Biochemical investigation Thyroid antibodies
T3 T4 TSH
HYPERTHYROIDSM
INCREASED
INCREASED
SUPPRESSED
T3 TOXICOSIS INCREASED
NORMAL SUPPRESSED
Contd…
Thyroid scan Toxic nodular goitre
Principles of treatment of thyrotoxicosis
Anti thyroid durgs Carbimazole and propylthiouracil, Beta blockers – propranolol and nadolol Iodides – reduce vascularity,
preoperative scenario Cannot cure toxic nodule
Contd…
Dosage – 10 mg of carbimazole tds can be increased up to 120mg per day.
Levels of TSH R Ab fall and permanent cure in 50%
BLOCK AND REPLACEMENT REGIMEN
Inhibit all T3 and T4 with high dose of carbimazole and replace with thyroxine 0.1-0.15mg
Surgery
Helps in reducing the mass of overactive tissue.
Reduction of TSH R Abs or only limited stimulation.
Toxic nodule – suppressed tissue acts normal after the surgery.
Radio Iodine
Destroys thyroid cells. Functioning tissue reduced beyond
critical level. Accurate dosage is difficult and may
require further dose after 12 weeks. No evidence proven – therapeutic
dosage is carcinogenic.
Anti- thyroid drugs
• No surgery and radio iodine effects
• prolonged• 50% failure
rate• difficult to
predict response.
• agranulocytosis or aplastic anemia
Surgery
• Goitre is removed
• Cure is rapid • High cure rate
• Permanent thyroid failure
• Hypoparathyroidism
• Recurrence <5%
Radioiodine
• No prolonged drug therapy
• indefinite follow up
• slow response• Accurate
dosage - difficult
Choice Of Therapy
Factors influencing Type of thyrotoxicosis Age of the patient Co existing medical illness Post treatment care Follow up Compliance and Patient wishes.
Diffuse Toxic Goitre
Radio Iodine
Age >45
Large goitre – surgery
Small goitre – antithyroid drugs or radio iodine
Age<45
Toxic Nodular Goitre
Enlarges with antithyroid drugs.
Responds poorly with drugs and radio iodine
Surgical removal is the treatment.
Toxic Nodule
Surgery vs Radio Iodine.
Pros and cons to be considered.
Special situations
Pregnancy
Radio iodine – absolute C/ISurgery – abortionDrugs – hypothyroidism both mother abd babySurgery in second trimester or careful administration of drugs
Children
Radio iodine – C/I
Surgery - recurrence
Drugs till adoloscents
Surgery later.
Thyrocardiac
Severe cardiac damage
Radio iodine with anti thyroid drugs
Hyperthyroidism Due To Rare Causes
Thyrotoxicosis factitia
Jod-Basedow Thyrotoxicosis Large doses of iodine in endemic goitre
deQuervain’s thyroiditis
Carcinoma
Preoperative preparation Extent of resection
Biochemically euthyroid
Antithyroid drugs
Block and replacement regimen
Lugol’s iodine
Beta blockers
Surgical optionsFeatures
Control of toxicity
Return to euthyroid state
Recurrence
Thyroid failure
Hypoparathyroidism
Followup
Total Thyroidectomy
Immediate
Immediate
None
100%
5%
Minimal
Subtotal thyroidectomy
Immediate
Variable
5%
25%
1%
lifelong
Thyrotoxic Crisis
Thyroid storm
Acute exacerbation
Etiology Inadequately preapred Infection / stress
Clinical features Dehydration Hyperpyrexia Tacycardia Diaphoresis
Contd…
Rx
Intravenous fluids / rehydration
Cooling the patient with ice packs
Diuretics
Manage cardiac failure with digoxin
Hydrocortisone
Specific Rx
Carbiamzole – 10-20mg q6hrly
Lugol’s iodine 10drops q8hrly
Sodium iodide 1g i.v
Propranolol 1-2 mg i.v
Post Operative Follow Up
Hypocalcemia
Thyroid function test
Replacement of thyroxine