1. Hyperthyroidism and Thyroid Storm
Tintinalli Chapter 215
12/15/05
Prepared by Trent W. Smith
Lecture by Dr. Klien MD

2. Normal Thyroid State
Synthesis and release of thyroid hormone is controlled by TSH relaesed form the anterior pituitary
TSH is controlled by the release of thyroid releasing hormone (TRH) from the hypothalmus and a negative feedback loop to the pituitary
Thyroid hormone production s dependent on adequate adequate iodine intake

3. Normal Thyroid State
Thyroid hormone is reversible bound to various proteins including thyronine-binding globulin (TBG)
Free unbound portions are biologically active
T4 is the predominant circulating hormone
T4 is deiodinated to t3
T3 is biologically more active than T4 but has a shorter half-life

4. Hyperthyroidism Occurs in in all ages
Uncommon under the age of 15
10 x’s more common in women (1/10,000)
Graves disease is the most common etiology
80% of cases in the U.S.
Common in the 3rd and 4th decades
Caused by autoimmune thyroid-stimulating antibodies
Associated with diffuse goiter, opthalmopathy, and local dermopathy

5. Hyperthyroidism
Toxic multinodular and toxic nodular goiters are the next most common etiologies
Usually occurs in older populations
Commonly with previous history of goiter
Often with milder symptoms of thyrotoxicosis

6. Hyperthyroidism Amiodarone-induced thyrotoxicosis (AIT)
Amiodarone is iodine rich and may cause both hyper and hypothyroidism
Difficult to treat because of incomplete understanding of mechanism
Two major forms exists
Type 1 occurs with a normal thyroid
Type 2 occurs with a abnormal thyroid
Tx. Varies based on the the type

7. Hyperthyroidism
Hyperthyroidism resembles a state of increased adrenergic activity despite a normal or low serum cortisol level
Classic complaints include heat intolerance, palpitations, weight loss, sweating, nervousness, and fatigue

8. Hyperthyroidism Symptoms Signs Weaknes Goiter/thyroid burit Fatigue
Hyperkinesis
Heat intolerance
Opthalmopathy
Nervousness
Lid retraction/stare
Increased sweating
Lid lag
Tremors
Tremor
Palpitations
Warm moist skin
Weight loss
Hyperreflexia
Hyperdefication
Tachycardia/arrhythmia
Dyspnea
Systolic hypertension
Menstrual abnormalities
Widened pulse pressure

9. Hyperthyroidism Confirmed by thyroid function test
Elevated free T4 and Low TSH
In some cases of graves disease T4 may be normal and TSH decreased but the patient appears thyrotoxic
T3 level should be done to rule out T3 toxicosis
Hypothyroidism secondary to pituitary adenoma will have elevated TSH levels

10. Hyperthyroidism Treatment
Palliative treatment of mild hyperthyroidism is accomplished using B-blockers
Most commonly used is propanolol
Treatment of Graves diseases include long-term use of antithyroid medications, radioactive iodine, or subtotal thyroidectomy
Type I AIT is treated with methimazole and potassium perchlorate
Type II AIT is treated with glucocorticoids

11. Hyperthyroidism Treatment cont.
Toxic multinodular goiter and solitary adenomas may be treated with radioiodine therapy
Thryoiditis is usually self limited and therapy is rarely needed

12. 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

13. Thyroid Storm Preciptatnts of Thyroid Storm (tabel 215-4) Infection
Trauma
DKA MI
CVA PE
Surgery
Withdrawal of thyroid med
Iodine administration
Palpation of thyroid gland
Ingestion of thyroid hormone
Unknown etiology (20-25%)

14. 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

15. 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

16. 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

17. Thyroid Storm Treatment
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

18. Thyroid Storm Drug Treatment of Thyroid Storm (table 216-6)
Decrease de novo synthesis:
Porpythiouracil mg PO initially, followed by 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 mg PO every day
Prevent peripheral effects:
B-Blocker Propanolol (IV) titrate 1-2 mg q 5min prn (may need mg PO q day) or Esmolol (IV) 500 mcg/kg IV bolus, then mcg/kg per min maintenance
Guanethidine mg PO q 6 h
Reserpine 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

19. 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

20. Thyroid Storm
Disposition
Admit to the ICU

21. Hypothyroidism and Myxedeam Coma
Tintinalli Chapter 215
12/15/05
Prepared by Trent W. Smith
Lecture by Dr. Klien MD

22. Hypothyroidism
Occurs when there is insufficient hormone production or secretion
Occurs more frequently in women (0.6 to 5.9 %)
The most common etiologies are
Primary thyroid failure due to autoimmune diseases (Hashimoto thyroiditis is the most common)
Idiopathic causes
Ablative therapy
Iodine deficiency
May be transient
Pathophysiology is unclear but may be viral in nature

23. Hypothyroidism Etiologies of Hypothyroidism Primary
Autoimmune etiologies
Hashimotos is the most common
Idopathic
Post ablation (surgical, radioiodine)
Post external radiation
Thryoiditis (subacute, silent, postpartum)
Postpartum thyroiditis occurs within 3-6 months and occurs in % of women
Self limited etiologies, often prededed by hyperthroid phase
Infiltrative disease (lymphoma, sarcoid, amyloidosis, Tuberculosis
Congenital

24. Hypothyroidism Etiologies of Hypothyroidism Post Partum
Occurs 3-6 months post partum and occurs in 2-16% of women
Secondary (pituitary)
Neoplasm
Infiltrative Dz.
Hemorrhage
Tertiary (hypothalamic)

25. Hypothyroidism Etiologies of Hypothyroidism Drugs Amiodarone Lithium
Occurs in 1-32% of patients
Most likely due to the large amount of iodine released in the metabolism of the drug which inhibits thyroid hormone synthesis, release, and conversion of T4 to T3
Lithium
Acts similarly to iodine and inhibit thyroid hormone release
Iodine (in patients with pre-existing autoimmune disease)
Antithyroid medication

26. Hypothyroidism Clinical Features
The typical symptoms of hypothyroidism include fatigue, weakness, cold intolerance, constipation, weight gain, and deepening of voice.
Cautaneous signs include dry, scaly, yellow skin, non-pitting, waxy edema of the face and extremities (myxedema): and thinning eyebrows

27. Hypothyroidism Clinical Features cont.
Cardiac findings include bradycardia, enlarged heart, and low-voltage electrocardiogram
Paresthesia, ataxia, and prolongation or DTR’s are characteristic neurologic findings
See table below for more complete list

28. Hypothyroidism Symptoms and Signs or Hypothyroidism (table 216-2)
Fatigue
Hoarseness
Weight Gain
Hypothermia
Cold intolerance
Periobital puffiness
Depression
Delayed relaxation of ankle jerks
Menstrual irregularities
Loss of outer third of eyebrow
Constipation
Cool, rough, dry skin
Joint Pain
Nonpitting edema
Muscle cramps
Bracycardia
Infertility
Peripheral Neuropathy

29. Hypothyroidism Treatment
Most patient with uncomplicated symptomatic Hypothyroidism may be referred to the primary physician for further evaluation and initiation of treatment
If hypothyroidism is due to a secondary etiology initiation of thyroid hormone therapy may exacerbate preexisting adrenal insufficiency

30. Myxedema
Myxedema is a rare life threatening decompensation of hypothyroidism
Usually in individuals with long-standing hypothyroidism
Most often seen in the winter months
More common in elderly women with underdiagnosed or undertreated hypothyroidism

31. Myxedema Precipitating events include Infection CHF Trauma CVA
Exposure to cold
Drugs
Sedatives
Lithium
Amiodarone

32. Myxedema
In addition to the clinical features of hypothyroidism patients may present with
Hypothermia
Altered metal status
Coma, delusions, and psychosis (myxedema maddness)
Hyponatremia
Dilutional secondary to decreased free-water clearance
Hypoglycemia
Secondary to impaired gluconeogenesis
Hypotension
Bradycardia
Respiratory Failure
Secondary to decreased strength of respiratory muscle
Hypercapnia and hypoxia is common

33. Myxedema Diagnosis Must have high clinical suspicion
Commonly has Hx. Of hypothyroidism
Delcine in function is usually insidious in onset

34. Myxedema Diagnosis cont Laboratory evaluation may reveal Anemia
Hyponatremia
Hypoglycemia
↑ Transaminases
↑ CPK
↑ LDH
↓Po2 and ↑PCo2 on ABG’s

35. Myxedema Diagnosis cont. EKG may reveal Sinus Bradycardia
Prolonged QT interval
Low voltage
Flattened or inverted T waves

36. Myxedema Treatment (see table 216-5 below)
No prospective studies on optimal therapy have been done thus treatment recommendations are not uniform
Airway stabilization with adequate oxygenation and ventilation or vital
Cardiovascular status must be monitored closely
Hypothermic patients should be gradually rewarmed with gentle passive external rewarming
Hypotension from reversal of hypothermic vasoconstriction should be avoided

37. Myxedema Treatment cont.
Hyponatremia typically responds to fluid restrictions. Severe cases may require hypertonic saline with lasixs
Vasopressors are usually ineffective and should only be used in severe hypotension
Lovothyroxine mcg slow IVP followed by mcg daily

38. Myxedema Treatment cont.
L-triiodothyronine 25 mcg IV or orally q 8 h is a alternative
This dose should be halved in patients with cardiovascular disease
Hydrocortisone 100 mg IV q 8 hours should be given
Send baseline cortisol level to lab if possible
Precipitating causes should be sought and treated

39. Myxedema Treatment of Myxedema Coma (table 216-5) Recognition
Supportive therapy including ventilatory support
Thyroid replacement
Lovothyroxine mcg slow IVP followed by mcg daily or
T3 25 mcg IV or PO q 8 hrs
Glucocorticoid
Hydrocortisone: 100 mg IV q8h
Hypothermia
Prevent additional loss
Passive external rewarming
Electrolyte correction
Gentle fluid restriction for dilutional hyponatremia
Hypertonic saline for severe hyponatremia
Hypoglycemia
Dextrose-containing IV fluids
Monitoring
Aggressive treatment of presipitating causes
Admit patient to a monitored setting

40. Myxedema
Disposition
Admit to appropiately monitored bed

41. Questions
1. Hyperthyroidism is Characterized by which of the following
A. Fatigue
B. Palpitations
C. Weight Loss
D. Heat intolerance
E. All the above

42. 2. The most common etiology of hyperthyroidism is
A. Toxic Multinodular
B. Graves
C. Toxic Nodular
D. Amiodarone induces

43. 3. Typical Feature of Hyperthyroidism include
A. Fatigue
B. Weakness
C. Constipation
E. Cold Intolerance
F. All the above

44. 4. T or F Hyperthyroidism is more common in women
5. T or F Hypothyroidism is more common in women
6. T or F Mild hyperthyroidism may be treated with B-blockers
Answers 1. E 2. B 3. F 4.T 5.T 6.T