Thyroid Disorders Student Notes 2024 PDF

Disorders of the Thyroid Gland DR. HAYAT MOHAMED  learning objectives 1. Anatomy and physiology of Thyroid gland 2. Disorders of the Thyroid Gland 3. Causes of these Disorders 4. Multisystem effects of these disorders 5. Diagnostics OF these Disorders 6. Management OF these Disor...

Disorders of the Thyroid Gland DR. HAYAT MOHAMED  learning objectives 1. Anatomy and physiology of Thyroid gland 2. Disorders of the Thyroid Gland 3. Causes of these Disorders 4. Multisystem effects of these disorders 5. Diagnostics OF these Disorders 6. Management OF these Disorders  Anatomy and physiology of Thyroid gland  The thyroid gland consists of two lobes connected by a middle piece called the isthmus;  The gland is located on the front and sides of the trachea just below the larynx.  Three hormones are produced by the thyroid gland. The T4 and T3 triiodothyronine [T3] and thyroxine [T4]) hormones are produced in the thyroid follicles, require iodine (T4 has four iodine atoms, T3 has three iodine atoms), and have the same functions.  Calcitonin is the third hormone produced by the thyroid gland; it is produced by parafollicular cells.  The direct stimulus for secretion of T4 and T3 is Thyroid- stimulating hormone(TSH ) from the anterior pituitary. The sequence of events is as follows: triiodothyronine [T3] and thyroxine [T4]).  A decrease in the metabolic rate (energy production) is detected by the hypothalamus, which secrets thyrotropin-releasing hormone (TRH).  TRH stimulates the anterior pituitary to secrete TSH, which stimulates the thyroid to increase secretion of T4 and T3, which increase energy production to raise the metabolic rate.  As the metabolic rate rises, negative feedback decreases the secretion of TRH from the hypothalamus until the metabolic rate decreases again.  Functions of thyroid Gland Functions of the T4 and T3 hormones  Increase energy production and protein synthesis.  Increases the metabolic rate—that is, energy and heat production.  The most important daily regulators of metabolic rate.  Their activity is reflected in the functioning of the heart, brain, muscles, and virtually all other organs.  They are essential for normal physical growth, mental development, and reproductive maturation. Functions of calcitonin hormone:  Important during childhood when bone growth is accelerated.  The maintenance of normal blood levels of calcium and phosphate and the maintenance of a strong, stable bone matrix.  Anatomy and physiology of Parathyroid Glands  There are usually four parathyroid glands, two on the back of each lobe of the thyroid gland.  The hormone they produce is called parathyroid hormone (PTH), which is an antagonist to calcitonin;  Secretion of PTH is stimulated by hypocalcemia (a low blood calcium level) and inhibited by hypercalcemia. Functions of parathyroid glands  It maintains normal blood levels of calcium.  It increases resorption of calcium and phosphate from the bones to the blood, which raises their blood levels. Disorders of Thyroid Gland  Problems with thyroid function are among the most common endocrine disorders. The thyroid hormones, thyroxine (T4) and triiodothyronine (T3), regulate energy metabolism and growth and development.  Disorders of the thyroid gland include goiter, benign and malignant nodules, inflammatory conditions leading to hyperthyroidism, and hypothyroidism Goiter  A goiter is an enlarged thyroid gland. In a person with a goiter, the thyroid cells are stimulated to grow. This may result in an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism).  The most common cause of goiter worldwide is a lack of iodine in the diet. Goitrogens (foods or drugs that contain thyroidinhibiting substances) can cause a goiter Thyroid Inhibitors Drugs Select Foods iodine in large doses Broccoli  Methimazole (Tapazole) Brussels sprouts Propylthiouracil (PTU) Cabbage Amiodarone Cauliflower Kale Lithium Mustard P-aminosalicylic acid Peanuts Salicylates Strawberries Turnips Sulfonamides  Thyroiditis, an inflammation of the thyroid gland. It is a frequent cause goiter. of Subacute granulomatous thyroiditis is thought to be caused by a viral infection. Acute suppurative thyroiditis is due to bacterial or fungal infection. chronic thyroiditis, which is usually autoimmune in nature. Subacute and acute forms of thyroiditis have an abrupt onset.  The patient reports pain localized in the thyroid or radiating to the throat, ears, or jaw. Systemic manifestations include fever, chills, sweats, and fatigue  Factors : include female gender, a positive family history, older age, and white ethnicity.  The goiter, which is the hallmark of Hashimoto’s thyroiditis, may develop gradually or rapidly. If it enlarges rapidly, it may compress structures in the neck (e.g., trachea, laryngeal nerves), changing the voice and affecting breathing. As thyroid tissue is destroyed by antibodies, there may be a transient phase of hyperthyroidism due to leaking thyroid hormone from the damaged tissues. silent, painless thyroiditis, which may be early Hashimoto’s thyroiditis, can occur in postpartum women. This condition is usually seen in the first 6 months after delivery. It may be due to an autoimmune reaction to fetal cells in the mother’s thyroid gland. T4 and T3 levels are initially increased in subacute, acute, and silent thyroiditis but become decreased with time. Suppressed radioactive iodine uptake (RAIU) is seen in subacute and silent thyroiditis. In Hashimoto’s thyroiditis, T4 and T3 levels are usually low and the TSH level is high. Antithyroid  If the thyroiditis is bacterial in origin, treatment may include specific antibiotics or surgical drainage.  In the subacute and acute forms, NSAIDs (aspirin, naproxenb [Aleve]) are used to relieve symptoms. With more severe pain, corticosteroids (e.g., prednisone up to 40 mg/day) can relieve discomfort.  Propranolol (Inderal) or atenolol (Tenormin) may relieve cardiovascular symptoms related to a hyperthyroid condition.  The patient who is hypothyroid needs thyroid hormone therapy.  The patient with Hashimoto’s thyroiditis is at risk for other autoimmune diseases, such as Addison’s disease, pernicious anemia, or Graves’ disease. Teach the patient the signs and symptoms of these disorders, particularly Addison’s disease.  Hypothyroidism Definition: Hypothyroidism is the diminished production of thyroid hormone, leading to thyroid insufficiency  Primary hypothyroidism: is caused by thyroid gland dysfunction;  Secondary hypothyroidism: from insufficient secretion of TSH by the pituitary gland  Tertiary: results when the hypothalamus gland does not secrete Thyrotropin-Releasing Hormone (TRH) , which stimulates the release of TSH  Causes of the hypothyroidism Hypothyroidism may result from:  Thyroidectomy  Radiation therapy  Chronic autoimmune thyroiditis (Hashimoto’s disease caused destroy the thyroid gland)  Inflammatory conditions  Hypothalamic failure to produce thyrotropin releasing hormone (TRH)  Inborn errors of thyroid hormone synthesis  Insufficient thyroid hormone replacement therapy for hyperthyroidism  Pituitary gland dysfunction due to infection, surgery, trauma, or tumor; autoimmune disease  Iodine deficiency; and drugs (such as lithium and amiodarone)  Hypothyroidism that develops in infancy (cretinism) results from thyroid hormone deficiencies during fetal or early neonatal life. All infants are screened for decreased thyroid function at birth.  Multisystem effects of hypothyroidism  Neurological: hand and foot paresthesias , Lethargy , Somnolence , Confusion , slow speech and memory impairment.  Endocrine : Goitre.  Respiratory : pleural effusion  Gastrointestinal : constipation  Musculoskeletal: muscle stiffness, weakness and fatigue  Sensory: periorbital edema  Cardiovascular: hypotension, bradycardia, dysrhythmias, enlarged heart and anemia.  Reproductive: menorrhagia (female), infertility (female) and decrease libido (male).  Integumentary: hair loss, brittle nails, dry skin, and Non-pitting edema.  Metabolic Processes: hypothermia, anorexia, constipation unexplained and weight gain periorbital edema  Multisystem effects of hypothyroidism  Myxedema : The face of a person with myxoedema appears puffy, the tongue is enlarged, and the voice is hoarse and husky  Also progressive , myxedema coma include stupor, hypoventilation, hypoglycemia. Diagnostics of the hypothyroidism  Measurement of serum TSH, T3, and T4, and free T4 levels; T3 resin uptake test; radioisotope thyroid uptake test Laboratory studies may show  A decreased serum T4 level, a decreased blood glucose level, decreased plasma osmolality.  A decreased TSH level (with a pituitary or hypothalamic defect)  A increased TSH level (with a thyroid defect), hyponatremia, hyperlipidemia, and lactic acidosis  Treatment The primary treatment it is lifelong replacement of the deficient hormone: synthetic; levothyroxine sodium or Liothyronine sodium or Liotrix that relieves symptoms in 2 to 3 days  If myxedema coma develops, immediate I.V. administration of a corticosteroid, glucose, and levothyroxine sodium can reverse this life- threatening condition Nursing Responsibilities for treatment (drug)  Give 1 hour before meals or 2 hours after meals just only water.  Monitor for bruising, bleeding gums, and blood in the urine. ( give anticoagulant drugs)  Monitor for signs of digitalis toxicity. ( give digitalis drugs) Digitalis Toxicity: Signs and Symptoms. *Cardiac arrhythmias and conduction disturbances. * Weakness, lethargy, anorexia, nausea, and vomiting  Monitor for manifestations of coronary insufficiency: chest pain, dyspnea, tachycardia  Monitor the effect of the insulin may change as thyroid function increases.  During dose adjustment, take pulse before administering drug. Report pulse > 100. Surgery If the hypothyroid patient has a goiter large enough to cause respiratory difficulties or dysphagia, a subtotal thyroidectomy may be performed. Nursing Responsibilities Preoperative care & Postoperative care Management hypothyroidism Nursing Care:  Health Promotion: Preventing hypothyroidism is education of the public about:  Adequate dietary intake of iodine.  Teach patients the regular healthcare provider visits and medication intake.  Management hypothyroidism cont… Nursing Care: Assessment: Health history: Pituitary disease history of hypothyroidism and treatment with medications or radioactive iodine, thyroid surgery, treatment of head or neck cancer with radiation, diet, use of iodized salt, bowel elimination, depression, muscle or joint aching, cold intolerance, respiratory difficulties, heavy menstrual periods. Physical assessment: Muscle strength, deep tendon reflexes, vital signs, cardiovascular and peripheral vascular systems, skin, thyroid gland, weight. Nursing diagnosis: Activity intolerance related to fatigue and depressed cognitive process  Goal: Increased participation in activities and increased independence Nursing Interventions 1. Promote independence in self-care activities. a. Space activities to promote rest and exercise as tolerated. b. Assist with self-care activities when patient is fatigued. c. Provide stimulation through conversation and non- stressful activities. d. Monitor patient’s response to increasing activities Expected Outcomes:  Participates in self-care activities  Reports decreased level of fatigue Nursing diagnosis: Risk for imbalanced body temperature  Goal: Maintenance of normal body temperature Nursing Interventions 1. Provide extra layer of clothing or extra blanket. 2. Avoid and discourage use of external heat source (eg, heating pads, electric or warming blankets). 3. Monitor patient’s body temperature and report decreases from patient’s baseline value. 4. Protect from exposure to cold and drafts. Expected Outcomes:  Experiences relief of discomfort and cold intolerance  Maintains baseline body temperature  Reports adequate feeling of warmth and lack of chilling Nursing diagnosis: Constipation related to depressed gastrointestinal function Goal: Return of normal bowel function Nursing Interventions 1. Encourage increased fluid intake within limits of fluid restriction. 2. Provide foods high in fiber. 3. Instruct patient about foods with high water content. 4. Monitor bowel function. 5. Encourage increased mobility within patient’s exercise tolerance. 6. Encourage patient to use laxatives and enemas sparingly. Expected Outcomes:  Reports normal bowel function  Drinks recommended amount of fluid each day Nursing diagnosis: Deficient knowledge about the therapeutic regimen for lifelong thyroid replacement therapy Goal: Knowledge and acceptance of the prescribed therapeutic regimen Nursing Interventions 1. Explain rationale for thyroid hormone replacement. 2. Describe desired effects of medication to patient 3. Assist patient to develop schedule and checklist to ensure self administration of thyroid replacement. 4. Describe signs and symptoms of over- and underdose of medication. 5. Explain the necessity for long-term follow-up to patient and family Expected Outcomes:  Administers medication to self as prescribed  Restates need for periodic/long-term follow-up visits to physician Nursing diagnosis: Ineffective breathing pattern related to depressed ventilation Goal: Improved respiratory status and maintenance of normal breathing pattern Nursing Interventions  1. Monitor respiratory rate, depth, pattern, pulse oximetry, and arterial blood gases. 2. Encourage deep breathing, coughing, and use of incentive spirometry. 3. Administer medications (hypnotics and sedatives) with caution. 4. Maintain patent airway through suction and ventilatory support if indicated Expected Outcomes:  Shows improved respiratory status and maintenance of normal breathing pattern Collaborative problem: Myxedema and myxedema coma Goal: Absence of complications Nursing Interventions 1. Monitor patient for increasing severity of signs and symptoms of hypothyroidism: a. Decreased level of consciousness; dementia b. Decreased vital signs (blood pressure, respiratory rate, temperature, pulse rate) c. Increasing difficulty in awakening or arousing patient 2. Assist in ventilatory support if respiratory depression and failure occur. 3. Administer prescribed medications (eg, thyroxine) with extreme caution. 4. Turn and reposition patient at intervals. 5. Avoid use of hypnotic, sedative, and analgesic agents. Expected Outcomes  Reports no episodes of angina or other indicators of cardiac insufficiency  Experiences minimal or no complications caused by immobility Nursing interventions  Administer replacement therapy as prescribed  Avoid sedating the patient, which may further decrease respirations  Recognize that slower metabolism may slow drug absorption and excretion  Provide frequent skin care to prevent breakdown and decrease the risk of infection  Administer fluids as prescribed; correct imbalances without causing fluid overload  Monitor fluid intake and output, and weigh the patient daily to check for fluid retention  If the patient has hypothermia, increase body temperature gradually by using warm blankets or increasing the room temperature  Encourage coughing and deep breathing, and administer oxygen as prescribed  Ask the patient and his family to demonstrate their understanding of the medication schedule  Give the patient and his family opportunities to ask about the disease and its treatment  Provide supportive care for a patient in myxedema coma; maintain a patent airway, monitor vital signs closely, and administer oxygen and I.V. fluid replacement until the patient begins to recover from the coma  Hyperthyroidism Hyperthyroidism : is a set of disorders involving excess synthesis and secretion of thyroid hormones by the thyroid gland, which leads to the hypermetabolic condition of thyrotoxicosis Risk factors:  Family history, high iodine intake, smoking, trauma to the thyroid gland (surgery), toxic multinodular goitre (particularly related to an increased intake of iodine, childbirth and highly active antiretroviral therapy.  Graves’ disease is genetic.  An increase in the peripheral circulation of unbound thyroid hormone can cause thyrotoxicosis.  Multisystem effects of hyperthyroidism Neurologic: hand and eye tremors, nervousness and insomnia, Sensory: blurred vision, photophobia Cardiovascular: hypertension, tachycardia, dysrhythmias, Palpitations. Reproductive: amenorrhea and decrease fertility in (female), impotence and decrease libido (male). Integumentary: fine, thin hair, flushed and moist skin Endocrine: goiter Respiratory: dyspnea Gastrointestinal: nausea, vomiting, diarrhea and abdominal pain Musculoskeletal: muscle wasting, weakness and fatigue. Metabolic Processes: hyperthermia, diaphoresis, hunger, weight loss and fluid volume deficit Diagnosis Laboratory tests show that:  Increased levels of thyroid hormones (triiodothyronine [T3] and thyroxine [T4])  Decreased thyroid-stimulating hormone (TSH) level Increased blood glucose level resulting from impaired insulin secretion Electrocardiography (ECG) shows atrial fibrillation, P- and T-wave alterations, and tachycardia; Thyroid scan shows increased uptake of radioactive iodine  Treatment The principal goal of treatment is to reduce thyroid hormone levels  Antithyroid medications are generally used for pretreating patients who are elderly or who have cardiac disease before starting radioactive iodine  Methimazole and propylthiouracil that block thyroid synthesis and typically produce improvement after 2 to 4 weeks of therapy;  A beta-adrenergic blocker such as propranolol may be used as an adjunct to control activity of the sympathetic nervous system Surgery (subtotal thyroidectomy) for patients with a very large gland, or who can’t undergo other treatments, or who have thyroid cancer Before surgery: the patient receives antithyroid medication to reduce hormone levels and saturated solution of potassium iodide to decrease surgical complications  Treatment Radioactive iodine therapy That based on the patient’s symptoms Contraindicated during pregnancy or breastfeeding The second goal of treatment is to prevent thyroid storm  The patient is taught to take medication (including an antipyretic) only as prescribed and to seek care for infection  Fluids are replaced as needed  A patient who develops thyroid storm requires immediate treatment with antipyretics and a hypothermia mattress, antithyroid drugs, steroids, beta blockers, and I.V. fluids  Nursing responsibilities for radioactive iodine therapy  Assess for hypersensitivity to iodine for example, ask the person about allergies to shellfish. Dilute liquid iodine sources in water or orange juice to disguise bitter taste. Monitor for increased bleeding if the person is also taking anticoagulants; iodine increases their effect. Management hyperthyroidism Nursing care Health promotion : preventable, it is vital to teach the importance of regular healthcare provider visits and maintain medication intake. Assessment Health history: other medical conditions, family history of thyroid disease, when symptoms began, severity of symptoms, intake of thyroid medications, menstrual history, changes in weight, bowel elimination. Physical assessment: S &S Nursing Diagnoses  Imbalanced nutrition, less than body requirements, related to exaggerated metabolic rate, excessive appetite, and increased GI activity  Ineffective coping related to irritability, hyperexcitability, apprehension, and emotional instability  Low self-esteem related to changes in appearance, excessive appetite, and weight loss  Altered body temperature Collaborative Problems/Potential Complications  Thyrotoxicosis or thyroid storm  Hypothyroidism Planning and Goals  The goals for the patient may be improved nutritional status, improved coping ability, improved self-esteem, maintenance of normal body temperature, and absence of complications. Improving Nutritional Status:  Ask the person to weigh daily  Teach the person the need for a diet high in carbohydrates and protein and including between-meal snacks.  Six small meals a day may be more desirable than three large meals.  Energy intake may need to be increased  Monitor nutritional status through results of laboratory data such as serum albumin. Enhancing Coping Measures  Reassurance that the emotional reactions  The environment is kept quiet and uncluttered.  The nurse encourages relaxing activities  The nurse instructs and reminds the patient to take the medications as prescribed.  The patient may require repetition of medications and written instructions. Improving Self-Esteem  The nurse conveys an understanding of the patient’s concern about changes in appearance,  If changes in appearance are very disturbing to the patient, mirrors may be covered or removed.  The nurse reminds family members and personnel to avoid bringing these changes to the patient’s attention.  Eye care and protection.  The patient should also be discouraged from smoking.  The nurse arranges for the patient to eat alone if desired and avoids commenting on the patient’s  Establish a trusting relationship; encourage the person to verbalize feelings about self and to ask questions about the illness and treatment.  Provide reliable information and clarify misconceptions. Maintaining Normal Body Temperature  The environment at a cool, comfortable temperature  Changes bedding and clothing as needed.  Cool baths and cool or cold fluids are encouraged Evaluation Expected Patient Outcomes 1. Improves nutritional status ( a. Reports adequate dietary intake and decreased hunger & Reports decreased episodes of diarrhea) 2. Demonstrates effective coping methods in dealing with family, friends, and coworkers a. Avoids stressful situations, events, and people b. Participates in relaxing, nonstressful activities 3. Achieves increased self-esteem  a. Verbalizes feelings about self and illness  b. Describes feelings of frustration and loss of control Nursing interventions  Maintain normal fluid and electrolyte balance to prevent arrhythmias  Tell the patient to avoid caffeine, which can stimulate the sympathetic nervous system  Provide a high-calorie, high-protein diet through several small, well-balanced meals  Ensure adequate hydration  Conserve the patient’s energy to help decrease metabolism needs  Prevent thyroid crisis by using a cooling mat to achieve normal temperature, keeping the patient’s room cool, establishing a calm environment, using relaxation techniques, administering drugs as prescribed, identifying and treating precipitating factors, and teaching the patient and family how to prevent thyroid storm Nursing interventions  If the patient has exophthalmos, administer eye drops or ointment, and encourage the use of sunglasses for comfort and to protect his eyes  If the patient has diaphoresis, keep his skin dry with powders that contain cornstarch, and frequently change his bed linens  If the patient underwent a thyroidectomy, keep him in Semi-Fowler’s position to promote venous return from the head; assess for signs of respiratory distress and vocal changes; keep a tracheotomy tray at the bedside; monitor him for signs of hemorrhage; assess for hypocalcemia (such as tingling and numbness of the extremities, muscle twitching, laryngeal spasm  Assess for signs of thyroid storm (such as tachycardia, fever, vomiting, and hypertension); and keep calcium gluconate available for emergency I.V. administration