Thyroid and Parathyroid Disorders Chapter 45 Thyroid and Parathyroid Disorders 1

Learning Objectives Identify nursing assessment data related to the functions of the thyroid and parathyroid glands. Describe tests and procedures used to diagnose disorders of the thyroid and parathyroid glands and nursing responsibilities relevant for each. Describe the pathophysiology, signs and symptoms, complications, and treatment of hyperthyroidism, hypothyroidism, hyperparathyroidism, and hypoparathyroidism. Assist in the development of nursing care plans for patients with disorders of the thyroid or parathyroid glands.

The Thyroid Gland Anatomy and physiology Located in lower portion of the anterior neck Two lobes, one on each side of trachea Lobes connected in front of trachea by a narrow bridge of tissue called the isthmus Plays a major role in regulating the body’s rate of metabolism and growth and development Produces thyroid hormone, triiodothyronine, calcitonin When does the hypothalamus stimulate the pituitary gland to secrete thyroid-stimulating hormone (TSH)? TSH in turn stimulates the thyroid gland to secrete hormones that affect the production and use of energy. 3

Figure 45-1 4

Age-Related Changes in Thyroid Function Increased incidence of thyroid nodules Serum levels of T4 remain approximately the same in a healthy older person, but levels of T3 often decline Incidence of hypothyroidism increases with age, especially among women Why are thyroid conditions often overlooked in the elderly? Treatment of thyroid disorders can have a profound positive effect on the patient’s quality of life. 5

Assessment of the Thyroid Gland Health history Changes in energy level, sleep patterns, personality, mental function, emotional state Unexplained weight changes In the review of systems, changes in menstrual cycles, sexual function, hydration, bowel elimination pattern, and tolerance of heat and cold 6

Assessment of the Thyroid Gland Physical examination Vital signs and height and weight Facial expression and characteristics as well as mental alertness Inspect/palpate skin for moisture, temperature, texture Hair texture Examine the eyes for exophthalmos (bulging) Inspect the neck for enlargement typical of goiter. Observe the hands for tremor Thyroid disorders may cause increased or decreased heart rate, respirations, blood pressure, and temperature as well as irregular heart rhythms. What are the key components of the nursing assessment of a patient with a thyroid disorder? 7

Assessment of the Thyroid Gland Diagnostic tests and procedures Serum T3, free T4, T4, and TSH Thyroid-releasing hormone (TRH) stimulation test Radioactive iodine (RAI) uptake test Thyroid ultrasonography MRI or CT 8

Hyperthyroidism 9

Characteristics of Hyperthyroidism Abnormally increased synthesis and secretion of thyroid hormones Graves’ disease Most common type of hyperthyroidism Autoimmune disorder Antibodies activate TSH receptors, which in turn stimulate thyroid enlargement and hormone secretion Most often develops in young women 10

Multinodular Goiter Often in women in their 60s and 70s Likely develop in people who have had goiter for a number of years Caused by small thyroid nodules that secrete excess thyroid hormone Increased hormone production is independent of TSH Nodules can be benign or malignant Symptoms are usually less severe 11

Signs and Symptoms Weight loss and nervousness with a mild form In more severe cases Restlessness, irritable behavior, sleep disturbances, emotional lability, personality changes, hair loss, and fatigue Weight loss, even when the patient is eating well, is common Poor tolerance of heat and excessive perspiration Changes in menstrual and bowel patterns Warm, moist, velvety skin; fine hand tremors; swelling of the neck; and ophthalmopathy including exophthalmos Tearing, light sensitivity, decreased visual acuity, and swelling around orbit of the eye Tachycardia, increased systolic blood pressure, sometimes atrial fibrillation 12

Figure 45-2 13

Complications Thyrotoxicosis Excessive stimulation caused by elevated thyroid hormone levels that produce dangerous tachycardia and hyperthermia What symptoms may be seen with thyrotoxicosis? Thyrotoxicosis is a medical emergency. Fortunately, modern treatment of hyperthyroidism makes this complication rare. 14

Medical Diagnosis Decreased TSH and elevated serum T4 Measurement of thyroid-stimulating antibodies and results of a radioactive iodine uptake test to diagnose Graves’ disease 15

Medical Treatment Drug therapy Radioactive iodine Surgical treatment Antithyroid drugs Thionamides and iodides Radioactive iodine Accumulates in the thyroid gland, where it causes destruction of thyroid tissue Surgical treatment Subtotal thyroidectomy Antithyroid drugs block the synthesis, release, or activity of thyroid hormones. Radioactive iodine accumulates in the thyroid gland, where it causes destruction of thyroid tissue. What side effects may occur with radioactive iodine treatment? 16

Care of the Nonsurgical Patient Assessment Activity tolerance, heat tolerance, bowel elimination pattern, appetite, weight changes, and food intake Mental-emotional state, adaptation to the condition, and understanding of the treatment Measure vital signs and height and weight Skin texture and edema 17

Care of the Nonsurgical Patient Decreased Cardiac Output Disturbed Sleep Pattern Hyperthermia Imbalanced Nutrition: Less Than Body Requirements Risk for Injury Disturbed Sensory Perception Diarrhea 18

Care of the Patient Having a Thyroidectomy Assessment: preoperative Identify and address learning needs Teaching: primary preoperative nursing intervention Goals: understanding of the usual preoperative and postoperative procedures and decreased anxiety Assessment: postoperative Assess and document respiratory status, level of consciousness, wound drainage or bleeding, voice quality, comfort, and neuromuscular irritability What is the primary preoperative nursing intervention? The patient usually recovers quickly from a thyroidectomy and may be discharged in 2 or 3 days. 19

Care of the Patient Having a Thyroidectomy Interventions Ineffective Airway Clearance Decreased Cardiac Output Disturbed Body Image Acute Pain Risk for Infection 20

Hypothyroidism Inadequate secretion of thyroid hormones Cretinism If not treated early, hypothyroidism during infancy causes permanent physical and mental retardation In adults can be serious but usually reversible with treatment Myxedema Facial edema from severe, long-term hypothyroidism 21

Figure 45-4 22

Figure 45-5 23

Hypothyroidism 24

Etiology and Risk Factors Primary Atrophy of the thyroid gland after years of Graves’ disease or thyroiditis Treatment for hyperthyroidism Dietary iodine deficiency High intake of goitrogens Defects in thyroid hormone synthesis Secondary Pituitary or hypothalamic disorders Thyroidectomy What foods may act as goitrogens? Hypothyroidism also can result from tissue resistance to thyroid hormone—that is, the hormone is present, but the body cells are unable to use it normally. 25

Signs and Symptoms Swelling of the lips and eyelids Dry, thick skin Bruising Thin, coarse hair Hoarseness Generalized nonpitting edema Facial edema May seem slow, depressed, or apathetic What causes the patient with hypothyroidism to gain weight? Hypothyroid patients commonly report lethargy, forgetfulness, and irritability; frequent headaches, constipation, menstrual disorders, numbness and tingling in the arms and legs, and intolerance to cold. 26

Medical Diagnosis Based on laboratory determination of free T4 and TSH Complications Myxedema coma Medical treatment Hormone replacement therapy Levothyroxine (Synthroid) or liothyronine (Cytomel) Infection, trauma, excessive chilling, and some drugs (opioids, sedatives, tranquilizers) may precipitate myxedema coma in a hypothyroid patient. What are the main signs of a life-threatening condition? 27

Assessment 45-28 28

Interventions Activity Intolerance Imbalanced Nutrition: More Than Body Requirements Hypothermia Constipation Risk for Impaired Skin Integrity Decreased Cardiac Output Disturbed Thought Processes Disturbed Body Image Self-Care Deficit 29

Simple Goiter Thyroid enlargement with normal hormone production Causes Iodine deficiency and long-term exposure to goitrogens The gland may enlarge to compensate for hypothyroidism Sometimes the enlarged gland produces excess hormones, making the patient hyperthyroid 30

Simple Goiter Treatment If mild enlargement and normal hormones, no intervention Some patients need hormone replacement therapy Surgery indicated if pressure on the trachea or esophagus or if the condition is disfiguring 31

Figure 45-6 32

Goiter Nodules Can be benign or malignant Physician may order a scan that uses radioactive iodine; determines cancer Nodular goiters usually surgically removed In benign conditions, only the nodule may be removed 33

Thyroid Cancer Uncommon Fatal in less than 1% of all cases Early stages: nodule that can be felt on thyroid If cancer spreads, enlarged lymph nodes felt in the neck Patient may not show dramatic changes in thyroid hormone levels Total thyroidectomy is the usual treatment If malignancy spreads beyond thyroid gland, more radical surgery may be indicated Surgery may be followed with radioactive iodine treatment to destroy any remaining tissue that might harbor malignant cells. What precautions must be taken due to the larger dose of radioactive iodine? 34

The Parathyroid Glands 35

Anatomy and Physiology Small glands located on back of thyroid Occasionally found in the mediastinum as well Usually 4 parathyroids; some people have more Embedded in thyroid, but function independently Secrete only one hormone, but it is vital Parathyroid hormone, or parathormone (PTH), plays a critical role in regulating the serum calcium level Calcium is an essential component of strong bones and plays a vital role in the functions of nerve and muscle cells. What is the role of PTH? 36

Figure 45-7 37

Nursing Assessment Health history Change in mental-emotional status, such as memory problems, irritability, or personality changes Musculoskeletal problems, including weakness, skeletal pain, backache, and muscle twitching or spasms Urinary frequency, polyuria, urinary calculi (stones), or constipation Head/neck radiation, renal calculi, chronic renal failure Medications, including calcium and vitamin D supplements 38

Nursing Assessment Physical examination Heart rate and rhythm, blood pressure, respiratory effort, muscle strength, muscle twitching, and hair and skin texture Chvostek’s sign Spasm of facial muscle when facial nerve tapped Trousseau’s sign Carpopedal spasm when a blood pressure cuff is inflated above the patient’s systolic blood pressure and left in place for 2 to 3 minutes What does a positive Chvostek’s or Trousseau’s sign indicate? 39

Figure 45-3 40

Diagnostic Tests and Procedures Blood tests Calcium, phosphate, creatinine, uric acid, magnesium, alkaline phosphatase, and PTH Radiographs Dental examination Electrocardiogram 41

Hyperparathyroidism 42

Characteristics Secretion of excess parathormone (PTH) Causes Tumor (an adenoma); can be benign or malignant Vitamin D deficiencies, malabsorption, chronic renal failure, and elevated serum phosphate Elevation of serum calcium (hypercalcemia) High levels of PTH cause calcium to shift from the bones into the bloodstream If untreated, severe demineralization of bone tissue People who receive a kidney transplant after having been on dialysis for a long time also may have hyperparathyroidism. What complications may occur due to excess levels of PTH? 43

Signs and Symptoms Symptoms vague at first Weakness, lethargy, depression, anorexia, and constipation Other findings include mental and personality changes, cardiac dysrhythmias, weight loss, and urinary calculi 44

Medical Diagnosis Elevated serum calcium and decreased serum phosphate Elevated PTH and 24-hour urine calcium Skeletal radiographs and bone density studies CT, MRI, ultrasound, fine-needle aspiration, and selective arteriography 45

Medical Treatment Surgical intervention Parathyroidectomy Surgeon attempts to leave some parathyroid tissue to prevent hypoparathyroidism 46

Medical Treatment Drug therapy Sodium and phosphorus replacements Calcitonin (Calcimar), gallium nitrate (Ganite), bisphosphonates (etidronate, pamidronate), and plicamycin (Mithracin) inhibit release of calcium from bones Furosemide (Lasix): promotes excretion of calcium in the urine Propranolol reduces PTH secretion 47

Assessment Monitor vital signs, urine output, weight, muscle strength, bowel elimination, and digestive disturbances 48

Interventions Activity Intolerance and Risk for Injury Impaired Urinary Elimination Constipation Disturbed Thought Processes Imbalanced Nutrition: Less Than Body Requirements 49

Postoperative Care Airway obstruction from accumulated fluid and blood in surgical site compressing the trachea Monitor and document the respiratory rate and effort and the pulse rate Increasing pulse and respiratory rates, especially accompanied by restlessness, suggest inadequate oxygenation Notify physician of indications of respiratory distress Keep an emergency tracheotomy tray at the bedside in the event of acute obstruction 50

Postoperative Care Airway obstruction related to severe hypocalcemia Be alert for tetany Tingling around mouth and in the fingers It may progress to severe muscle spasms or cramps and even to laryngospasm Treated with oral or intravenous calcium supplements 51

Postoperative Care Protect suture line from stress Show patient how to support the head when changing positions Inspect dressing and back of the neck for bleeding Elevate patient’s head to reduce swelling Where is the incision usually located? 52

Hypoparathyroidism Deficiency of parathormone (PTH) Uncommon condition From accidental removal of/damage to parathyroid glands during surgery Primary hypoparathyroidism can be caused by an autoimmune process and by several conditions, including Wilson’s disease (copper overload) Inadequate secretion of PTH leads to hypocalcemia Severe hypocalcemia can progress to convulsions and respiratory obstruction due to spasms of the larynx 53

Hypoparathyroidism Signs and symptoms Painful muscle cramps, fatigue and weakness, tingling and twitching of the face and hands, mental and emotional changes, dry skin, and urinary frequency With severe hypocalcemia, difficulty breathing, convulsions, and cardiac dysrhythmias 54

Hypoparathyroidism Medical diagnosis Medical treatment Low serum calcium, elevated serum phosphate, low urine calcium, and sometimes low serum magnesium Chvostek’s sign and Trousseau’s sign Medical treatment Acute hypoparathyroidism: sometimes parenteral PTH Severe hypocalcemia: with intravenous calcium salts Chronic hypoparathyroidism: with oral calcium salts and a form of vitamin D 55

Hypoparathyroidism Interventions Administer drugs as ordered If recent seizure activity or if patient shows severe neuromuscular irritability, follow seizure precautions Pulse/blood pressure for dysrhythmias/heart failure Teach signs and symptoms of calcium imbalances, and provide instructions for self-medication Advise patient to carry medical ID card to alert health care providers in event of an emergency When administering calcium salts intravenously, monitor the infusion site carefully because the leakage of calcium salts into body tissues causes inflammation. What complication may be suggested by respiratory distress? 56