Anesthetic considerations of thyroid disease

Anesthetic considerations of thyroid disease 報告人: R1 何長勳 Case data Chart number:16864608 Name:林張海萍 Sex: female Age:76 y/o Admission date: 94/08/25 Chief complain: Dyspnea off and on for one more weeks Past History: HTN with medication TB s/p treatment one year ago Present Illness • About 20years ago. She noted a mass over her anterior left neck which was tenderless, fixed, well difinited and 2*2 cm in size. • She did not pay attention to it. • Body weight loss about 3kg in half year • 3 month ago, she noted another mass lesion over her right anterior neck about 4*3 cm in size. • The mass enlarged more, then dysphagia, hoarseness and SOB was noted later. Pressent Illness • Thyroid echo with puncture showed enlarged thyroid gland with multiple hypoechoic and isoechoic nodules in both lobes are noted • Multinodular goiter with cystic degeneration was impressed. • There was no hand tremor, palpitation, blurred vision,and heat or cool intolerance • she was admitted on 8/25 Physical Examination • Vital signs：BT 35.6℃, BP 158/80㎜Hg, PR 69/min, RR 20/min • no exophathalmos • Neck: a mass 2x2cm in size, fixed, illdefined,palpable hard on anterior left neck another mass 4x3cm in size,movable while swallowing,well-defined,palpable-elastic located at right anterior neck,no palpable LN enlargement Laboratory data Clinical examination • 8/26 Sputum acid fast stain: negative • 8/26 Chest CT :Multinodular thyroid goiter with downward extension into mediastinum • 9/1 Fine needle: follicular cell PMN and colloid with acute inflammation • 9/5 Heart echo:LVEF:79 % Mild to moderate AR, TR; mild PR • PFT: FEV1/FVC 68.4% Operation on 9/8 and operative findings • A big mass 10*8cm in size arise form left lobe of thyroid gland, contained necrosis and fibrotic mass with entension from lower neck into upper mediatinum and displaced traches right anteriorly, esophagus compression posteriorly • Frozen section of left lobe: Inflammatory tumor mass • Perform: Left lobectomy+right subtotal thyroidectomy 5# J-P drain in it. • 9/8 17:25 Transfered to ward via O2 mask 6L/min • Vital sign stable. Wound CD qd. Steam inhalation qid at ordinary ward. • Pathological report:(1) nodular goiter with focal adenomatous hyperplasia and Hurthle cell change (2) acute suppurative inflammation with abscess formation • 9/11 remove J-P drain • 9/15 Discharge Disscussion Thyroid physiology • Iodine is absorbed by GI tract, converted to iodide ion. • Iodide oxidized back to iodine and bound tyrosine. • Triiodothyronine(T3), Thyroxine(T4) • A feedback control of thyroid hormone involves thyrotropin-releasing hormone (TRH), the anterior pituitary ( TSH), and autoregulation (thyroid iodine) • Increase carbohydrate and fat metabolism • Oxygen consumption and CO2 production • HR, Contractility, and catacholamine levels increase Goiter • I. Diffuse goiter: 1.Graves’ disease: T3/ T4 ↑ 2.Hashimoto thyroitis: T3/T4 ↓ II. Nodular: 1.multiple: a. endemic goiter: T3/T4↓ b. Plummer’s disease (toxic multinodular goiter) T3/ T4 ↑ 2.Single: a. 60% colloid nodule: T3/T4 normal b. 30% follicular andnoma T3/T4 normal (↑) c. 5% thyroid cancer:T3/T4 normal(↓later) Hyperthyroidism • Weight loss, heat intolerance, muscle weakness, diarrhea, hyperactive reflexes, and nervousness • Fine tremor, exophthalmos, or goiter may be noted • Sinus tachycardia, atrial fibrillation and congestive heart failure • TX: 1. Propylthiouracil, methimazole 2.Potassium, sodium iodide 3.Propranolol 4.Radioactive iodine destory thyroid cell 5.Subtotal thyroidectomy Preoperative anesthetic considerations • Patient is euthyroid with medical treatment • Resting heart rate less then 85/min • Benzodiazepines are a good choice for preoperative sedation • Antithyroid medications and ß-adrenergic antagonists are continued through the morning of surgery • Hyperdynamic circulation can be controlled by titration of esmolol infusion (emergency surgery) Intraoperative anesthetic considerations • Cardiovascular and body temperature • Protect patient’s eye • Operative table raise 15-20 degrees to aid venous drain and decrease blood loss (but air embolism risk) • Endotracheal tube • Avoid ketamine, pancuronium, and indirect-acting adrenergic agonists (HR ↑ BP ↑) • Thiopental may be the induction agent (antithyroid) Intraoperative anesthetic considerations II • Chronic hypovolemic and vasodilation • Avoid tachycardia, hypertension and ventricular dysrhythemias • Neuromuscular blocking agent should be used cautiously ( thyrotoxicosis, myopathies and myasthenia gravis) • Hyperthyroidism does not increase anesthetic requirements Post operative anesthetic considerations I • A:Thyroid storm: hyperpyrexia, tachycardia, altered consciousness (eg, agitation, delirium, coma) • Onset usually 6-24 hours after surgery • Not associated muscle rigidity, elevated creatine kinase or marked degree of lactic and respiratory acidosis. • Tx: hydartion, cooling, esmolol infusion propranolol IV (0.5 mg until HR< 100/min) • Propylthiouracil (250 mg every 6 hours) followed by sodium iodine ( 1gm IV over 12 hours) • Cortisone (100-200 mg every 8 hrs)prevent coexisting adrenal supression Post operative anesthetic considerations II • B: recurrent laryngeal nerve palsy: Hoarsness( unilateral) , aphonia, stridor (bilateral) tx: intubation and exploration of the wound • C: Hematoma formation :Airway compromise from collapse of the trachea , tracheomalacia tx: endotracheal intubation immediatedly, open wound check bleeding, debridement • D: Hypoparathyroidism: numbness, nervous ness, anxiety, tetany, Chvostek’s sign,Trousseau’s sign Tx: Calcium gluconate IV Hypothyroidism • Weight gain, cold intolerance, muscle fatigue, lethargy, constipation, hypoactive reflexes, dull facial expression and depression • HR, CO, myocardial contractility, peripheral vasoconstriction • Lower free T4 level • Myxedema coma results from extreme hypothyroidism: hypoventilation, hypothemia, hyponatremia( SIADH), Congestive heart failure • Loding dose of T3/T4 300-500mg of levothyoxine sodium without heart disease, maintenance infusion 50mg /day • Steroid replacement (hydrocoticsone 100mg IV Q8h) for coexisting adrenal supression Preoperative anesthetic considerations • Severe hypothyroid, myxedema should be treated with thyroid hormone. • Hypothyroid patients with CAD benefit form a delay thyroid therapy until after CABG • Do not require much preoperative sedation • H2 antagonist and metoclopramide should be given due to slower gastric-emptying times • Received usual dose of thyroid medicaiton • Half time of T4 is about 8 days Intraoperative anesthetic considerations • Hypotensive effect of anesthetic agents due to CO↓,blunted baroreceptor reflexes and intravascular volume ↓ • Ketamine is often used for induction anesthesia • CO ↓ speed the rate of induction with an inhalational anesthetic ( MAC no decrease) • Hypoglycemia, anemia, hyponatremia, difficult intubation( large tongue) ,hypothermia Post operative anesthetic considerations • Recovery form GA may be delayed by hypothermia, respiratory depression, slowed drug biotransformaion • Remain intubated until awake and close to normothermic • Ketorolac would be a good choice for post operation pain relief Thank you for your attention