This document summarizes hypothyroidism and hyperthyroidism in the elderly. It discusses laboratory tests for thyroid function like TSH, T4, and T3. It describes signs and symptoms of hypothyroidism like fatigue, weight gain, and constipation. Physical exam findings in hypothyroidism include bradycardia, puffy features, and dry skin. Myxedema coma is a life-threatening complication of untreated hypothyroidism. Symptoms and signs of hyperthyroidism include weight loss, palpitations, and tremors. Physical exam may reveal lid lag, goiter, and tachycardia. Thyroid storm is a medical emergency caused by excessive thyroid hormone levels

1. Hypothyroidism and Hyperthyroidism in the Elderly Chien Yung-Chang , MD .

3. Free T4 Reference range 0.7-1.8 ng/Dl . Converted to triiodothyronine (T3) . The thyroid gland is the sole source of T4 . Free T4 measures the nonprotein-bound circulating T4 .

4. Total T4 Normal range 50-120 ng/mL , 5-12 mcg/dL . Measurement of total T4 is not particularly helpful . Only 0.03% of T4 circulates in the unbound state . There is no clinical indication for performing total thyroid hormone measurement .

5. TSH Normal 0.4-5.5 mIU/L . Serum TSH will be decreased to<0.1 mIU/L in most hyperthyroid patients . The findings of a low serum T4 and low TSH mandate a search for pituitary disease .

6. T3 T3 is more biologically active . Binding proteins : thyroid-binding globulin , transthyretin and albumin . T3 thyrotoxicoisis : approximately 5% of clinically hyperthyroid patients with a normal free T4 level .

7. Functional examinations Measure the uptake of iodine into the thyroid gland . The iodine isotopes : used to identify nodular thyroid disease , to determine if these nodules are hot ( functioning ) or cold ( hypofunctioning ) , to determine the cause for the hyperthyroid state ( Graves’ disease vs thyroiditis ) and to determine a dose of radioiodine for treatment .

8. Erythrocyte sedimentation rate To confirm the diagnosis of subacute ( viral ) thyroiditis in patients with tenderness on thyroid palpation .

9. The Role of the History in Diagnosing Hypothyroidism Previous thyroid ablation . Elevated thyroid autoantibodies . Thyroid surgery . Medicatins containing lithium or iodine . The most common cause of hypothyroidism is autoimmune or Hashimoto’s thyroiditis .

10. Signs and Symptoms of Hypothyroidism Less active than usual with loss of interest in things previously enjoyed . Lethargy , and decreased mobility . Fatigue . Dry skin .

11. Sings and Symptoms of Hypothyroidism (continued ) Apathy and psychomotor retardation . Weakness , arthralgia , myalgia , coarsening of the voice , constipation , edema , weight gain , cold intolerance . Alveolar hypoventilation => CO2 retention and coma .

12. The Physical Examination in Hypothyroidism Hypotension or diastolic hypertension . Low body temperature and bradycardia . Facial features that are puffy and coarse . The skin : dry and cold . Carotenemia : An orange or yellow tint without scleral icterus .

13. The Physical Examination in Hypothyroidism ( continued ) Brittle nails and hair , pallor , induration and thickening of skin , periorbital edema , macroglossia , and myxedema . Mental status change . Delayed relaxation time of deep tendon reflex . Pleural , peritoneal and pericardial effusion . Delirium and psychosis .

14. The Heart in the Hypothyroid State Decreased stroke volume , bradycardia , and decreased cardiac output . Diastolic hypertension . Sinus bradycardia and a prolonged PR and QT intervals . Low voltage , heart block , T-wave flattening or inversion , Torsades de pointes , and sudden death .

15. The Heart in the Hypothyroid State ( continued ) Echocardiogram may be useful to show regional wall abnormalities . It also will diagnose a pericardial effusion . Pericardial tamponade is rare .

16. Laboratory Diagnosis of Hypothyroidism Levels of TSH : high . The levels of free T4 : decreased . Vitamin B 12 deficiency => macrocytic anemia . Erythropoietin levels also are low => fall in hematocrit . Hyponatremia with low serum osmolality .

17. Laboratory Diagnosis of Hypothyroidism ( continued ) Hypoglycemia . Cardiac enzymes may be elevated . Without AMI , the troponin I level remains normal . Adrenal hypofunction .

18. Laboratory Diagnosis of Hypothyroidism ( continued ) Elevation of thyroid microsomal antibodies is => chronic autoimmune ( Hashimoto’s ) thyroiditis . Thyroid antibodies may be associated with : Grave’s disease , vitiligo , myasthenia gravis , Addison’s disease , pernicious anemia , and other autoimmune diseases .

19. The Diagnosis of Myxedema Coma Abnormal TSH and free T4 values : confirm the diagnosis .( in the presence of nonpitting edema , hypoventilation , hypothermia and stupor ) Hyponatremia , hypoglycemia , and associated infection : confirmatory .

20. Precipitating Events for Myxedema Coma Surgery , severe infection , and trauma . Sedatives , narcotics , and tranquilizers . Missed doses of T4 .

21. Clinical Features of Myxedema Coma Alteration in mental status , presence of a precipitating factor , hypothermia , and increased serum CK levels . Pale and edematous . Respiratory symptoms . Ascites , pericardial effusion and pleural effusion .

22. Clinical Features of Myxedema Coma ( continued ) Distant heart sounds , bradycardia , high serum cholesterol levels and low voltage on the EKG . Dyspnea on exertion , fatigue , and edema . Distended abdomen , paralytic ileus , and fecal impaction . Myxedema megacolon : pseudomembranous colitis and intestinal ischemia .

23. Clinical Features of Myxedema Coma ( continued ) Disturbance in consciousness : ranging from delirium to stupor and coma . Hallucination ( myxedema madness ) , cerebellar signs and somnolence . Muscle relaxation times of the deep tendon reflexes : delayed markedly . Hyponatremia => seizure and depressed level of consciousness .

24. Laboratory Database of Myxedema Coma Serum TSH and free T4 levels , blood glucose , electrolytes , and arterial blood gas . Serum cortisol . Chest films , urinalysis , and blood cultures . CK , and SGOT . Serum electrolytes ,creatinine , BUN ,and glucose should be monitored .

25. Treatment of Myxedema Coma Thyroid hormone replacement : the definitive treatment . Intravenous therapy : preferred . Give steroids when starting thyroid replacement => avoid precipitating adrenal crisis . Passive rewarming and maintenance of appropriate hydration status .

26. Factors Associated with poor come Advantaged age . Body temperature lower than 93*F . Hypothermia persisting more than three days . Bradycardia less than 44 beats/minute . Hypotension , MI ,and sepsis .

27. Initiation of Treatment in ED for Myxedema Coma 200-300 mcg ( 4 mcg/kg ) IV bolus thyroxine , followed by 50-100 mcg QD . T3 20 mcg IV bolus ( loading dose 10-25 mcg ) , then 10 mcg Q8-12H for 24-48 hours until the patient is conscious and taking maintenance T4 . Hydrocortisone 100 mg Q8H .

28. Initiation of Treatment in ED for Myxedema Coma ( continued ) Evidence of infection =>Antibiotics . Underlying illness => Supportive care . Consider elective intubation . Severe hyponatremia => Consider hypertonic saline . Consider appropriate rewarming technique .

29. Recommendation for Admission for the Hypothyroid Patient Clinical diagnosis of myxedema coma => ICU admission . Body temperature less than 93*F or bradycardia less than 44 beats /min => ICU admission . Comorbidity : CHF ,cachexia , COPD , pneumonia , or any pulmonary problem .

30. Recommendation for Admission for the Hypothyroid Patient ( continued ) Underlying disorder : aspiration pneumonia , urosepsis , MI . CNS dysfunction : Seizure , ataxia , somnolence , lethargy , confusion , or coma . Behavioral disorders : Disorientation , paranoia , or hallucination ( myxedema madness ) .

31. Recommendation for Admission for the Hypothyroid Patient ( continued ) Hypoglycemia : suggesting hypopituitarism or adrenal insufficiency . Hyponatremia less than 128 mEq/L . Social factors that jeopardize patient safety .

32. Symptoms and Signs of Thyrotoxicosis weight loss ( the most common ) , palpitation , weakness , dizziness and syncope . Alteration in mental status . Heat intolerance . Nervous or restlessness .

33. Symptoms and Signs of Thyrotoxicosis ( continued ) Tracheal compression => SOB, hoarseness , wheezing and stridor .( Pemberton’s sign ) Thyromegaly => wheezing , hoarseness , stridor , or dysphagia . Myopathy : the proximal muscle groups of the shoulder and pelvic girdles .

34. Symptoms and Signs of Thyrotoxicosis ( continued ) Memory loss , confusion and short attention span . Chorea , delirium , convulsion , stroke , cerebral venous thrombosis , and coma . Some psychiatric conditions => may be mistaken for thyrotoxicosis .

35. Physical Findings in the Hyperthyroid State Flushed skin.Hyperhidrosis of the palms and soles . Alopecia . Fine and brittle hair . Fever and tachycardia . Lid lag , chemosis , exophthalmosis , vasodilation of the conjunctiva , edema of the lids , and compromised visual acuity . Myxedema of the pretibial areas , feet , and toes .

36. Physical Findings in the Hyperthyroid State ( continued ) Diffuse enlargement , bruit , nodules , and tenderness. Abdominal pain or secretary diarrhea . Muscle weakness , hyperactive reflexes , and tremor .Alteration in mental status . Dementia and severe psychomotor retardation . ( Apathetic hyperthyroidism )

37. The Heart in Thyrotoxicosis Diminished diastolic BP . Palpitation .Decreased exercise tolerance . Dyspnea on exertion .Elevated systolic BP . Sinus tachycardia . Atrial fibrillation . Anigina pectoris . EKG : shortening of the PR interval , ST change , or atrial fibrillation .

38. Laboratory Testing in Thyrotoxicosis Suppressed TSH levels and increased serum free T4 estimates : clinically evident thyrotoxicosis ( 95% ) . Radioactive iodine uptake => incereased . ESR => elevated markedly . Serum thyroglobulin => increased .

39. Thyroid Storm A life-threatening crisis . Estimated mortality : 20-30% . the result of thyroid surgery . Caused more often by antecedent Grave’s disease .

40. Precipitants of Thyroid Storm Surgery . Radioiodine therapy . Iodinated contrast dyes . Thyroid hormone ingestion . Diabetic Ketoacidosis . Cerebrovascular accident . Pulmonary embolism and CHF .

41. Pathophysiology of Thyroid Storm 1) An acute decrease in thyroxine-binding globulin => high levels of free hormone . 2) Thyroid hormone increases the density of beta-adrenergic receptors & alters responsiveness to catecholamines at a postreceptor level .

42. Diagnosis of Thyroid Storm Largely a clinical diagnosis . CNS disturbances occur in 90% of patients . Atrial arrhythmia and ventricular tachyarrhythmia may complicate high output CHF . Many of the stigmata of the hyperthyroid state may be present .

43. Laboratory Diagnosis of Thyroid Storm A combination of low TSH and elevated free T4 => makes the diagnosis . If TSH is lower than normal and free T4 is normal => free T3 testing is recommended . ED measurement of thyroglobulin or thyroid antibodies : No indication .

44. Treatment of Thyroid Storm Block hormone synthesis with either : a) Propylthiouracil 100-600 mg loading PO or NG , 200-250 mg q4h for total daily dose of 1200-1500 mg ; or b) methimazole 20 mg PO ( 10-40 mg range ) q 4h .

45. Treatment of Thyroid Storm ( continued ) Inhibit hormone release : Iodides –Potassium iodide ( SSKI ) 5 drops PO Q6-8H , or Lugol’s solution 7-8 drops ( 1 mL PO Q6H ) or Ipodate 1-3 g daily ( as 1 g Q8H for 24 hours , then 500 mg Q12H ) . If severe iodide allergy , lithium carbonate 300 mg Q6H .

46. Treatment of Thyroid Storm ( continued ) Glucocorticoids : Hydrocortisone ( 300 mg IV , then 100 mg IV q8h ) ; dexamethasone ( 2 mg Q6H ) . Adrenergic blockade : Propranolol ( 0.5-3 mg IV over 15 minutes slow IV , then 60-80 mg PO Q4H ) ; Esmolol ( 0.25-0.5 mcg/kg loading , infusion of 0.05-0.1 mcg/kg/min ) .

47. Adjunctive Therapy for Thyroid Storm Treat fever aggressively with acetaminophen . IV fluid containing 10% dextrose are recommended . Administer vitamin supplements , including thiamine . Treat CHF with conventional methods .

48. Adjunctive Therapy for Thyroid Storm ( continued ) Identify the precipitating event , including infection . Consider plasmapheresis , hemodialysis or peritoneal dialysis for removal of metabolically active hormone .

49. Admission Criteria for the Hyperthyroid Elderly Patient Impending or clinical thyroid storm . Clinical hyperthyroidism and : a) CNS effects , including agitation , chorea , delirium , psychosis , seizure , or coma ; b) GI effects such as frank diarrhea , vomiting , jaundice , dehydration , or abdominal pain ;

50. Admission Criteria for the Hyperthyroid Elderly Patient ( continued ) c) Cardiovascular dysfunction , including CHF , sinus tachycardia unresponsive to oral beta blocade in the ED , new onset atrial fibrillation , or angina pectoris ; d) Persistent fever > 100.4*F after rest , without source or without easily treatable source ; e) Syncopal episode ;

51. Admission Criteria for the Hyperthyroid Elderly Patient ( continued ) f) History of recent radioiodinevtherapy ; or g) Thyrotoxic periodic paralysis ( address hypokalemia ) . Underlying precipitating cause .