THYROTOXICOSIS DR.J.BALA KUMAR 2 ND YR SURGERY PG
What is the difference between thyrotoxicosis and hyperthyroidism
Thyrotoxicosis Thyrotoxicosis is defined as the state of thyroid hormone excess and is not synonymous with hyperthyroidism, which is the result of excessive thyroid function. However, the major etiologies of thyrotoxicosis are hyperthyroidism caused by Graves' disease, toxic MNG, and toxic adenomas.
Symptoms of Thyrotoxicosis Hyperactivity, Irritability, Heat intolerance and sweating Palpitations Fatigue and weakness Weight loss with increased appetite Diarrhea Polyuria Oligomenorrhea, loss of libido
Signs of Thyrotoxicosis Tachycardia; atrial fibrillation in the elderly Tremor Goiter Warm, moist skin Muscle weakness, proximal myopathy Lid retraction or lag Gynecomastia
Ophthalmopathy in Graves' disease; lid retraction, periorbital edema, conjunctival injection, and proptosis are marked
Treatment Anti thyroid drugs Surgery radioiodine
Anti thyroid drugs Carbimazole 10mg tid or qid for latent period of 7 14 days To continue same till biochemically euthyriod Followed by 5 mg tid or qid 6 to 24 months Alternatively high dose along with thyroxine 0.1 to 0.15mg od Propylthiouracil 100 300 mg tid Beta blockers 10 days pre op to reduce vascularity Recurrence 50% in all Advantage avoid surgery, radioactive material
surgery Cure possible if thyroid reduced below critical mass Its due to reduction of TSH R Ab If some tissue left behind circulating TSH R Ab can cause hypertrophy & hyperplasia Thyroid insufficiency in 20 45% Recurrence in 5%
Radio iodine I131 Destroys thyriod cells Adv No surgery or prolonged therapy Disadvantage long term follow up, insufficiency Insufficency in 75 80% in 10 yrs 200 600 MBq dose/ 8 12 mci Results expected at 8 12 weeks Dose adjusted after 12 weeks
Choice of treatment Diffuse toxic goitre age > 45 radioactive iodine Age < 45 anti thyroid drugs or radioiodine Radioiodine in persons who completed family Toxic nodular goitre surgery Toxic nodule surgery, age > 45 radioiodine Recurrent thyrotoxicosis after surgery radioiodine Rx of choice in young anti thyroid drugs Failure of Rx surgery or radioabalation
Problems in Rx Pregnancy all contraindicated Antithyroid drugs tried propylthiouracil Post partum propylthiouracil Children antithyroid drugs High titres autoantibodies antithyroid or steriods Recent onset proptosis anti thyroid drugs till proptosis static for 6 months followed by surgery or radioiodine Baby of hyperthyroid mother no medication as it subsides in 3 4 weeks
Thyrotoxicosis factitia Hyperthyroidism caused by taking thyroxine > 0.15 0.25mg Reduction of dose is Rx
Surgery Bilaterally Sub total thyroidectomy One side total thyroidectomy with other side subtotal thyroidectomy (hartley dunhill procedure) Ideal remnant tissue is 3 7 g in adults & < 3 g in children
Complications of surgery Hemorrhage Respiratory obstruction Recurrent laryngeal nerve paralysis Thyroid insufficiency Para thyroid insufficiency Thyroid storm (thyrotoxic crisis) Wound infection Hypertrophic scar / keloids Stitch granuloma
Thyroid Storm A life threatening hypremetabolic state due to hyperthyroidism Mortality rate is high (10 75%) despite treatment Usually occurs as a result of previously unrecognized or poorly treated hyperthyroidism Thyroid hormone levels do not help to differentiate between uncomplicated hyperthyroidism and thyroid storm
Thyroid Storm Preciptatants of Thyroid Storm Infection DKA CVA Surgery Iodine administration Ingestion of thyroid hormone Trauma MI PE Withdrawal of thyroid med Palpation of thyroid gland Unknown etiology (20-25%)
Thyroid Storm Clinical features The most common signs are fever, tachycardia out of proportion to the fever, altered mental status, and diaphoresis Clues include a history of hyperthyroidism, exophthalmoses, widened pulse pressure and a palpable goiter Patients may present with signs of CHF
Thyroid Storm Clinical features cont. Common GI symptoms include diarrhea and hyperdefication Apathetic thyrotoxicosis is a distinct presentation seen in the elderly Characteristic symptoms include lethargy, slowed mentation, and apathetic facies Goiter, weight loss, and proximal muscle weakness also present
Thyroid Storm Diagnosis Thyroid storm is a clinical diagnosis based upon suspicion and treated empirically Lab work is non specific and may include Leukocytosis, hyperglycemia, elevated transaminase and elevated bilirubin
Treatment Thyroid Storm Initial stabilization includes airway protection, oxygenation, fluids and cardiac monitoring Treatment can then be divided into 5 areas: General supportive care Inhibition of thyroid hormone synthesis Retardation of thyroid hormone release Blockade of peripheral thyroid hormone effects Identification and treatment of precipitating events
Thyroid Storm Drug Treatment of Thyroid Storm (table 216-6) Decrease de novo synthesis: Porpythiouracil 600-1000mg PO initially, followed by 200-250 mg q 4 hrs Methimazole 40 mg PO initial dose, then 25 mg PO q6h Prevent relases of hormone (after synthesis blockade intiated) Iodine Iaponoric acid (Telepaque) 1 gm IV q8h for the first 24 h, then 500 mg bid or Potassium iodide (SSKI) 5 drops PO q6h or Lugol solution 8-10 drops PO q6h Lithuim 800-1200 mg PO every day Prevent peripheral effects: B-Blocker Propanolol (IV) titrate 1-2 mg q 5min prn (may need 240-480mg PO q day) or Esmolol (IV) 500 mcg/kg IV bolus, then 50-200 mcg/kg per min maintenance Guanethidine 30-40 mg PO q 6 h Reserpine 2.5-5 mg IM q4-6h Other consideration: Corticosteroids Hydrocortisone 100 mg IV q 8 h or dexamethosone 2 mg IV q 6 hr Antipyretics Cooling blanket acteaminophen 650 mg PO q 4-6h
Thyroid Storm Treatment cont Propranolol has the additional effects or blocking perpheral conversion of T4 T3 Avoid Salicylates because it may displace T4 from TBG If the patient continues to deteriorate despite appropriate therapy circulating thyroid hormone may be removed by plasma transfusion, plasmapheresis, charchoal plasmaperfusion Remember you must not administer iodine until the synthetic pathway has been blocked
Thyroid Storm Disposition Admit to the ICU
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