Thyroid Case Study

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Thyroid DisordersChapter 50


Structures and Functions of Endocrine Structures and Functions of Endocrine SystemSystem

• Endocrine glands • Released directly into circulation

or have local effect• Hormone secretion is regulated by

a process call Feedback


Thyroid Disorder• Located in the lower neck anterior to the trachea• Regulated by Thyroid-stimulating hormone (TSH)


Structures and Functions of Endocrine Structures and Functions of Endocrine SystemSystem

• Thyroid Hormone–Thyroxine (T4)

–Triiodothyronine (T3) • Regulate cellular metabolism by increasing oxygen

consumption

–Calcitonin• Reduce plasma level of Calcium by increasing

deposition in bone


Hyperthyroidism• A sustained increase in synthesis and release of

thyroid hormones by thyroid gland• Occurs more often in women, ages 20 to 40 years

• Most common form – Graves’ disease

• Other causes– Toxic nodular goiter– Thyroiditis– Excess iodine intake– Pituitary tumors– Thyroid cancer


Continuum of Thyroid Dysfunction


Etiology and PathophysiologyGraves’ Disease

• Antibodies to TSH receptor stimulate release of T3, T4, or both– Leads to clinical manifestations of

thyrotoxicosis

• Remissions and exacerbations• May progress to destruction of thyroid

tissue


Hyperthyroidism

• Thyrotoxicosis– Physiologic effects/clinical syndrome of

hypermetabolism

– Results from increased circulating levels of T3, T4, or both

• Hyperthyroidism and thyrotoxicosis usually occur together


Etiology and PathophysiologyGraves’ Disease

• Autoimmune disease– Diffuse thyroid enlargement – Excessive thyroid hormone secretion

• Accounts for 80% of hyperthyroidism cases

• Precipitating factors interact with genetic factors

• Cigarette smoking increases risk


Clinical Manifestations

• Related to effect of thyroid hormone excess– ↑ Metabolism– ↑ Tissue sensitivity to stimulation by

sympathetic nervous system• Goiter

– Inspection– Auscultation: bruits



• Ophthalmopathy– Abnormal eye appearance or function

• Exophthalmos– Increased fat deposits and fluid– Eyeballs forced outward


Exophthalmos and Goiter of Graves’ Disease


Clinical Manifestations• Cardiovascular system

– Systolic hypertension– Bounding, rapid pulse; palpitations– ↑ Cardiac output– Cardiac hypertrophy– Systolic murmurs– Dysrhythmias (e.g., atrial fibrillation )– Angina

• Respiratory system– Increased respiratory rate– Dyspnea on mild exertion



• GI system– ↑ Appetite, thirst– Weight loss– Diarrhea– Splenomegaly – Hepatomegaly



• Integumentary system– Warm, smooth, moist skin– Thin, brittle nails– Hair loss– Clubbing of fingers; palmar erythema– Fine, silky hair; premature graying– Diaphoresis– Vitiligo


Acropachy



• Musculoskeletal system– Fatigue– Muscle weakness– Proximal muscle wasting– Dependent edema– Osteoporosis



• Nervous system– Nervousness, fine tremors– Insomnia , exhaustion– Lability of mood, delirium– Hyperreflexia of tendon reflexes– Inability to concentrate – Stupor, coma



• Reproductive system– Menstrual irregularities – Amenorrhea– Decreased libido– Impotence– Gynecomastia in men– Decreased fertility



• Intolerance to heat• Elevated basal temperature• Lid lag, stare• Eyelid retraction• Rapid speech


Thyrotoxicosis (Thyrotoxic Crisis)

• Excessive amounts hormones released• Life-threatening emergency• Death rare when treatment initiated • Results from stressors• Thyroidectomy patients at risk


Thyrotoxicosis• Manifestations

– Tachycardia, heart failure– Shock– Hyperthermia– Restlessness, irritability– Seizures– Abdominal pain, vomiting, diarrhea– Delirium, coma


Thyrotoxicosis

• Treat by reducing circulating hormones• Supportive therapy

– Manage respiratory distress– Reduce fever– Replace fluids– Eliminate or manage initiating stressor


Diagnostic Studies of Endocrine Diagnostic Studies of Endocrine System System

• Thyroid laboratory studies– Thyroid-stimulating hormone (TSH)– Thyroxine (T4) total– Free thyroxine (FT4)– Triiodothyronine (T3) total– Free triiodothyronine (FT3)– T3 uptake (T3 resin uptake)– Thyroid antibodies (Ab)– Thyroglobulin


Diagnostic Studies of Endocrine Diagnostic Studies of Endocrine System System

• Thyroid radiologic studies– Ultrasonography– Thyroid scan – Radioactive iodine uptake (RAIU)


Diagnostic Studies

• ↓ TSH and ↑ free thyroxine (free T4)

• Total T3 and T4

• Radioactive iodine uptake (RAIU)– Differentiates Graves’ disease from other

forms of thyroiditis


Collaborative Care

• Three primary treatment options– Antithyroid medications– Radioactive iodine therapy (RAI)– Surgery


Drug Therapy

• Useful in treatment of thyrotoxic states• Not considered curative

– Antithyroid drugs– Iodine– β-Adrenergic blockers


Antithyroid Drugs

• Propylthiouracil (PTU) and methimazole (Tapazole)

• Inhibit synthesis of thyroid hormone • Improvement in 1 to 2 weeks • Good results in 4 to 8 weeks• Therapy for 6 to 15 months


Iodine

• Potassium iodine (SSKI) and Lugol’s solution

• Inhibit synthesis of T3 and T4 and block their release into circulation

• Decreases vascularity of thyroid gland• Maximal effect within 1 to 2 weeks• Used before surgery and to treat crisis


β-Adrenergic Blockers

• Symptomatic relief of thyrotoxicosis• Block effects of sympathetic nervous

stimulation• Propranolol (Inderal) • Atenolol (Tenormin)


Radioactive Iodine Therapy (RAI)

• Treatment of choice in nonpregnant adults

• Damages or destroys thyroid tissue• Delayed response of 2 to 3 months • Treated with antithyroid drugs and β-

blocker before and during first 3 months of RAI


Radioactive Iodine Therapy (RAI)

• Given on outpatient basis• Patient teaching

– Oral care for thyroiditis/parotiditis– Radiation precautions– Symptoms of hypothyroidism


Surgical Therapy

• Indications– Large goiter causing tracheal compression– Unresponsive to antithyroid therapy– Thyroid cancer– Not a candidate for RAI

• More rapid reduction in T3 and T4 levels


Surgical Therapy

• Subtotal thyroidectomy – Preferred surgical procedure– Involves removal of 90% of thyroid– Can be done endoscopically


Nutritional Therapy

• High-calorie diet (4000 to 5000 cal/day)– Six full meals/day with snacks in between– Protein intake: 1 to 2 g/kg ideal body

weight– Increased carbohydrate intake

• Avoid highly seasoned and high-fiber foods, caffeine

• Dietitian referral


Nursing Assessment

• Subjective data– Past health history

• Goiter, recent infection or trauma, immigration from iodine-deficient area, autoimmune disease

– Medications• Thyroid hormones, herbal therapies

– Weight loss– Increased appetite, thirst– Nausea/vomiting, diarrhea, polyuria– Decreased libido - Impotence -Amenorrhea


Nursing Assessment• Objective data

– Agitation, Rapid speech, Anxiety, restlessness– Enlarged or nodular thyroid gland– Exophthalmos – Eyelid retraction, infrequent blinking– Thin, loose nails– Fine, silky hair and hair loss– Palmar erythema– Clubbing– Vitiligo– Edema– Warm, diaphoretic, velvety skin


Nursing Assessment

• Objective data– Tachypnea, dyspnea on exertion– Tachycardia, murmurs, dysrhythmias, HTN, bruit– ↑ Bowel sounds, ↑ appetite, diarrhea, weight loss– Hepatosplenomegaly

• Objective data– Hyperreflexia, diplopia– Fine tremors– Muscle wasting


Nursing Assessment

• Objective data– ↑ T3, ↑ T4

– ↑ T3 resin uptake

– ↓ Or undetectable TSH– Chest x-ray showing enlarged heart– ECG findings of tachycardia, atrial fibrillation


Nursing Diagnoses & Plan

• Activity intolerance • Imbalanced nutrition: less than body

requirements

• Overall goals– Experience relief of symptoms– Have no serious complications related to

disease or treatment– Maintain nutritional balance– Cooperate with therapeutic plan


Nursing ImplementationAcute Thyrotoxicosis

• Necessitates aggressive treatment• Medications to block thyroid hormone

production• Monitoring for dysrhythmias and oxygenation• Fluid and electrolyte replacement• Ensure adequate rest

– Calm, quiet room– Cool room– Light bed coverings


Nursing ImplementationAcute Thyrotoxicosis

• If exophthalmos present– Apply artificial tears to relieve eye discomfort– Salt restriction and elevate head of bed– Dark glasses– Tape eyelids closed if needed for sleep– ROM of intraocular muscles


Nursing ImplementationPreoperative Care

• Administer medications to achieve euthyroidism

• Administer iodine to ↓ vascularity• Assess for signs of iodine toxicity• Patient teaching

– Comfort and safety measures– Leg exercises, head support, neck ROM– Routine postoperative care


Nursing ImplementationPostoperative Care

• Monitor for complications– Hypocalcemia– Hemorrhage and ifection– Laryngeal nerve damage– Thyrotoxic crisis

• Maintain patent airway– O2, suction equipment, tracheostomy tray at bedside– Monitor for laryngeal stridor– IV calcium readily available



• Assess every 2 hours during first 24 hours for signs of hemorrhage or tracheal compression

• Semi-Fowler’s position• Support head with pillows• Avoid neck flexion and tension on

suture line



• Monitor vital signs and calcium levels• Signs of hypocalcemia

– Difficulty speaking and hoarseness– Trousseau’s and Chvostek’s signs

• Analgesics• Ambulation• Psychosocial support


Nursing ImplementationAmbulatory and Home Care

• Discharge teaching– Monitor hormone balance periodically– Decrease caloric intake – Adequate but not excessive iodine intake– Regular exercise– Avoid ↑ environmental temperature– Complete thyroidectomy

• Symptoms of hypothyroidism• Need for lifelong thyroid hormone replacement

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Hypothyroidism

• Deficiency of thyroid hormone • Slow metabolic rate• More common in women than in men


Etiology and Pathophysiology

• Primary hypothyroidism• Caused by destruction of thyroid tissue or

defective hormone synthesis

• Secondary hypothyroidism• Caused by pituitary or hypothalamic

dysfunction (↓ TSH or TRH)


Etiology

• Iodine deficiency • Atrophy of the gland• Treatment for hyperthyroidism• Drugs• Cretinism if occurs in infancy



• Manifestations variable• Slow onset• Cardiovascular system

• ↓ Cardiac contractility and output• Angina, heart failure, myocardial infarction• Anemia• Cobalamin, iron, folate deficiencies• ↑ Serum cholesterol and triglycerides



• Respiratory system• Low exercise tolerance• Shortness of breath on exertion

• Neurologic system• Fatigue and lethargy• Personality and mood changes• Impaired memory, slowed speech, decreased

initiative, and somnolence


Clinical Manifestations• Gastrointestinal system

• Decreased appetite• Nausea and vomiting• Weight gain• Constipation• Distended abdomen• Enlarged, scaly tongue• Celiac disease


Clinical Manifestations• Integumentary system

• Dry, thick, inelastic, cold skin• Thick, brittle nails• Dry, sparse, coarse hair• Poor turgor of mucosa• Generalized interstitial edema• Puffy face• Decreased sweating• Pallor


Clinical Manifestations• Musculoskeletal system

• Fatigue, weakness• Muscular aches and pains• Slow movements• Arthralgia

• Reproductive system• Prolonged menstrual periods or amenorrhea• Decreased libido, infertility



• Other• Increased susceptibility to infection• Increased sensitivity to opioids,

barbiturates, anesthesia• Intolerance to cold• Decreased hearing• Sleepiness• Goiter


Common Features of Myxedema


Complications• Myxedema coma

• Impaired consciousness• Precipitated by infection, drugs, cold,

trauma• Subnormal temperature, hypotension,

hypoventilation• Cardiovascular collapse• Treat with IV thyroid hormone


Diagnostic Studies

• History and physical examination

• TSH and free T4 • TSH ↑ with primary hypothyroidism• TSH ↓ with secondary hypothyroidism

• Thyroid antibodies• ↑ Cholesterol• ↑ Triglycerides• ↑ Creatine kinase• ↓ RBCs (anemia)


Collaborative Care• Levothyroxine (Synthroid)

• Start with low dose• Monitor for cardiovascular side effects

(chest pain, dysrhythmias), weight loss, nervousness, tremors, insomnia

• Increase dose in 4- to 6-week intervals as needed

• Lifelong therapy


Nursing Assessment

• Health History• Hyperthyroidism treatment

• Iodine-containing medications

• Changes in appetite, Weight gain

• Activity level

• Speech, memory, or skin changes

• Physical examination• Cold intolerance• Constipation• Signs of

depression• Heart rate• Gland tenderness• Edema


Nursing Diagnoses

• Imbalanced nutrition: more than body requirements

• Constipation• Impaired memory


Nursing Implementation

• Health promotion• Screen populations at high risk

• Family history of thyroid disease• History of neck irradiation • Women older than 50• Postpartum women



• Most outpatient therapy• Myxedema coma necessitates acute care

• Mechanical respiratory support• Cardiac monitoring• IV thyroid hormone replacement• Monitoring of core temperature



• Acute intervention• Skin care• Vital signs, weight, I&O, edema• Cardiovascular response to hormone• Energy level • Mental alertness



• Patient teaching• Written instructions important• Need for lifelong therapy• Thyroid medicine in morning on empty

stomach• Side effects of medication• Signs and symptoms of hypothyroidism and

hyperthyroidism



• Patient teaching• Regular follow-up care• Do not switch brands• Comfortable, warm environment• Measures to prevent skin breakdown• Emphasize need for warm environment• Avoid sedatives or use lowest dose possible• Measures to minimize constipation• Avoid use of enemas

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Thyroid Case Study

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