Thyroid Gland.docx

**Hyperthyroidism and Hypothyroidism** **THYROID GLAND** \- anterior to the trachea; butterflyshaped and wrapped around trachea \- highly vascular, butterfly shaped organ \- consists of two lobes of tissue situated on either side of the trachea below the Adam\'s apple \- wraps around the windpi...

**Hyperthyroidism and Hypothyroidism** **THYROID GLAND** \- anterior to the trachea; butterflyshaped and wrapped around trachea \- highly vascular, butterfly shaped organ \- consists of two lobes of tissue situated on either side of the trachea below the Adam\'s apple \- wraps around the windpipe (trachea) and has a shape that is similar to a butterfly formed by two wings (lobes) and attached by a middle part (isthmus). \- removes iodine from the blood (which comes mostly from a diet of foods such as seafood, bread, and salt) and uses it to produce thyroid hormones (T3, T4) \- Positive feedback occurs to increase the change or output: the result of a reaction is amplified to make it occur more quickly. \- **Negative feedback o**ccurs to reduce the change or output: the result of a reaction is reduced to bring the system back to a stable state.; present in blood calcium regulation; prevente uncontrolled release of hormones **Thyroid Gland** \* Thyroid hormones: T3 and T4 \* lodine is contained in the thyroid hormone \* Thyroid hormone controls cellular metabolic activity \* T3 is more potent and more rapid-acting than T4 **Functions of T3 and T4** \* Increase metabolic activity of most body tissues \* Increase oxygen utilization, HR, contractility and cardiac output, rate and depth of respiration \* Increase utilization of food for energy \* Increase protein synthesis and proteolysis, carbohydrate metabolism and catabolism and lipolysis \* Stimulate mental processes and neuromuscular responses \* Promote growth and development of fetuses and children \* Maintain normal reproductive function  **HYPERTHYROIDISM** \* Hypermetabolic, overactive state associated with an excess of T3 and T4 or both; bodily processes is increased \* Characterized by hypertrophy and hyperplasia of the thyroid gland, which is accompanied by increased vascularity and blood flow and enlargement of the gland. Common causes of hyperthyroidism include: \* Graves\' Disease \- the most common cause of hyperthyroidism \- thought to be an autoimmune disease **Antibodies**: \- thyroid stimulating immunoglobulin (TSI antibodies, IgG type--- most significant lab results \- thyroid peroxidase antibodies (TPO), and \- TSH receptor antibodies. \- bind at the TSH at the receptor sites and stimulate thyroid growth, increased
vascularity, hypersecretion of the thyroid hormones- T3 **TOXIC NODULAR GOITER**  **Toxic Multinodular Goiter (TMNG)** \- a nodule may become \"autonomous.\" - does not respond to pituitary regulation via TSH and produces thyroid hormones independently \- more likely if the nodule is larger that 3 cm. \- If there is more than one functioning nodule \* More common in women than in men; occurs in about 2% of the female population \* Excessive intake of thyroid hormone - levothyroxine \* A tumor in the pituitary gland may produce an abnormally high secretion of TSH (the thyroid stimulating hormone)- pituitary adenoma **3 Principal Hallmarks:** **\* Thyroid gland enlargement** (diffuse, toxic goiter)-gland continues to grow and make own thyroid hormones \*goiter can also occur when client has HYPO since anterior pituitary glsnd will make effort TSH- causing frequent stulation of thyroid gland- increased activity cauding increased size\* \* **Exophthalmos** (infiltrative ophthalmopathy) - results from accumulation of fluid in the fat pads behind the eyeball and inflammatory edema of the extraocular muscles; difficulty closing of eyes \* **Hyperthyroidism** \- the triggers for this disease include stress, smoking, and infectious organisms such as viruses. **Clinical Manifestations** \* Nervousness, emotional lability, irritability, apprehension. \* Difficulty in sitting quietly. \* Rapid pulse at rest and on exertion (ranges between 90 and 160); palpitations. \* Heat intolerance; profuse perspiration; flushed skin (eg, hands may be warm, soft, moist). \* Fine tremor of hands \* Change in bowel habits - often with diarrhea. \* Increased appetite and progressive weight loss; frequent stools. \* Muscle fatigability and weakness; amenorrhea. \* Atrial fibrillation possible (cardiac decompensation common in older patients)- from palpitations \- predispose to clot formation \* Bulging eyes (exophthalmos) - seen
only in Graves\' disease. \* Thyroid gland may be palpable and a BRUIT may be auscultated over gland. \* Course may be mild, characterized by remissions and exacerbations. \* It may progress to emaciation, extreme nervousness, delirium, disorientation, THYROID STORM or crisis, and death. **THYROID STORM** \- or crisis, an extreme form of hyperthyroidism, is characterized by hyperpyrexia (as high as 40 degrees), diarrhea, dehydration, tachycardia, arrhythmias, extreme irritation, tremors, delirium, coma, shock, and death if not adequately treated. \- Thyroid storm may be precipitated by stress (surgery, infection, abrupt withdrawal of antithyroid medications and adrenergic blockers) or inadequate preparation for surgery in a patient with known hyperthyroidism. \****Euthyroid***- T3 and T4 levels should be normal \* For fever -NO SALICYLATES - increase thyroid hormone level; aggrevates thyroid levels **PHARMACOTHERAPY** \* propylthiouracil (PTU), methimazole (Tapazole). \- Act by depressing the synthesis of thyroid hormone \- PTU also blocks the conversion of T4 hormone to the more metabolically active T3 hormone. \- Acts to prevent release of thyroid hormone into circulation by increasing the amount of thyroid hormone stored within the gland. \- May interfere with RAI (radio active iodine) treatment and may exacerbate the disease in some people. - no ptu days before RAI treament \- May be given in divided daily doses (PTU) or in a single daily dose (Tapazale). \- The major risk of these medications is occasional suppression of production of white blood cells by the bone marrow (agranulocytosis; prone to infection).- report fever/sore throat, thrombocytopenia (bleeding), s/sx of hypothyroidism ***PTU*** - used in 1st trimester; liver enzymes- can be hepatotoxic; does not cause teratogenic effects ***Methimazole*** - fewer side-effects BUT not given during 1st trimester; teratogenic \* Once PTU therapy is begun, abrupt withdrawal may precipitate thyroid crisis. \* Duration of treatment is determined by clinical criteria. \- Thyroid gland becomes smaller. \- Treatment continued until patient becomes clinically euthyroid; this varies from 3 months to 2 years; \- Therapy is withdrawn gradually to prevent exacerbation. \* if euthyroidism cannot be maintained without therapy, then radiation or surgery is recommended. \* Drugs to control peripheral manifestations of hyperthyroidism: **PROPRANOLOL** (Inderal) \* Acts as a beta-adrenergic blocking agent. \* Inhibits peripheral conversion of T4 to T3 \* Abolishes tachycardia, tremor, excess sweating, nervousness. \* Controls hyperthyroid symptoms until antithyroid drugs or radioiodine can take effect (2-3 days) \* If severe bradycardia develops, atropine may be required. \* Contraindicated when the client is having bronchospasm (COPD) **CORTICOSTEROIDS**: dexamethasone (Decadron) \* reduces peripheral conversion of
Is from Ta by suppressing the immune system. May be given before thyroidectomy and discontinued after surgery. \* Decreases hyperthermia; \* inhibits calcium absorption **STRONG IODINE SOLUTION** (Lugol\'s solution) or supersaturated potassium iodide (SSKI) PO \* May be used as surgical preparation to decrease size and vascularity of the gland or to treat thyroid storm. \- to prevent intra and post surgical hemmorhaging \* If iodide is part of treatment, mix with milk, juice, or water to prevent Gl distress \* administer through a straw to prevent tooth discoloration. \* **S**- Shrinks the thyroid before removal \* **S-** Stains teeth (use straw) \* **K**- Keep 1 hour apart from other meds **Emergency Management of Thyroid Storm** \* Inhibition of new hormone synthesis with thioamides (PTU). \* Inhibition of thyroid hormone release using iodine (Lugol\'s solution). \* Inhibition of peripheral effects of thyroid hormones with propranolol (Inderal), corticosteroids, and thioamides (PTU). **QUICK REVIEW** \* HYPERTHYROIDISM \- HIGH T3 AND T4 \- CAUSES: GRAVES DISEASE, LEVOTHYROXINE, IODINE EXCESS \- CLASSIC SIGNS: Go Get High \* G - Graves disease \* G - Goiter \* H - High BP (MI, CVA, Aneurysm); High HR (Tachycardia); Hot and sweaty skin; Heat intolerance; High GI movement (diarrhea \* **RADIOACTIVE IODINE THERAPY (RAIU)- I-131** \- treatment of choice for almost all patients with Graves\' disease because it destrovs abnormally functioning gland tissue. Action: limits secretion of thyroid hormone by destroying thyroid tissue. \- Dosage is controlled so that hypothyroidism does not occur. \- Chief advantage over thioamides is that a lasting remission can be achieved. \- Chief disadvantage is that permanent hypothyroidism can be produced, not for pregnant and nursing women \- Side-effects: metal taste in the mouth, swollen salivary glands, nausea \- Peak results take 6-12 wk (several treatments may be necessary); however, a single dose controls hyperthyroidism in about 90% of patients. \* **BEFORE**: \- Negative pregnancy test \- 5-7 days before: HOLD ANTITHYROID MEDS \- Awake (No anesthesia or conscious sedation) \- NPO: 2-4 hours BEFORE, 1-2 hours AFTER ***General Guidelines to follow to lower the risk of exposing others to radiation. Follow the precautions below for 7 days after treatment.*** \* Travelling home from the hospital: \- Sit as far away from the driver as you can. For example, sit opposite the driver in the back seat. There should be no other passengers. \* Once at home: \- Stay at home in your own room and minimize contact with others. \- Wear slippers or socks at all times. \- Do not return to work and school. \- Do not travel on public transit or attend public events. \* Drinking fluids and sucking candy: \- Most of the extra radioactive iodine is eliminated in your urine. \- It is important to drink fluids after treatment and for the next 2 days. This lowers the amount of radiation exposure to the bladder. \- Suck on sour candy after treatment to help the radioactive iodine come out in the saliva. **TIME** \* The less time you spend around other people the better. This is very important with children and pregnant women. \* Avoid being close to pregnant women and children for at least 7 days. \* When you are around people, spend no more than: \- 45 minutes a day at 1 meter or 3.5 feet or \- 2 hours a day at 2 meters or 7 feet or \- 7 hours a day at 3 meters or 10 feet \- can spend as much time as you like at 4 meters or 13 feet from other people. **DISTANCE** \* The greater distance from other people the better. For example, doubling your distance from someone decreases exposure by a factor of ¼. Examples of increasing distance include: \- Sleep alone. \- Do not sit right beside someone on a couch or in a vehicle. \- Sit as far away as you can from the person driving you home from the hospital. \- Do not use public transit. \- Do not go to the theatre or any event where you would be close to people. \* Good hygiene is very important to reduce exposure to others. \- Make sure no one uses your soap or towels. \- Wash your hands with soap and plenty of water each time you use the toilet. \- Have at least 1 daily shower. No baths. \- Keep the toilet and surrounding area very clean. \- Men must urinate sitting down to avoid splashing. \- Flush the toilet 3 times with the lid closed after each use. \- Rinse the bathroom sink, shower and tub thoroughly after using. \- After brushing your teeth, spit into the toilet then flush the toilet 2 times. \- Flush all used facial tissue down the toilet. **\* Food and dishes** \- Use separate dishes and wash separately. \- Eat prepared food or prepare your own food separately from the people in your home. \- Avoid foods that have residue that needs throwing away. **\* Clothes, bedding and towels** \- Wash separately. \- After your precaution time is over wash all items 2 times before returning to general use in your home. **\* Close contact** \- Avoid kissing and sexual intercourse. \* Do not become **pregnant** or father a child after having radioactive iodine for 6 months. You may want to talk to your doctor about how to prevent a pregnancy. \* Treatment aimed at systemic effects of thyroid hormones and prevention of decompensation. \- Hyperthermia - cooling blanket, acetaminophen (Tylenol). \- Dehydration - administration of I.V. fluids and electrolytes. \* Treatment of precipitating event. **Thyroidectomy** \* The goal is to remove the thyroid tissue that was producing the excessive thyroid hormone. Thyroidectomy can be: \- total (removal of the entire thyroid gland); \- subtotal (95% of gland removed) to prevent damage to the parathyroid glands; and \- Partial or Thyroid Lobectomy (one lobe or isthmus removed) to treat nodular disease. **Preoperative Management** \* Preoperative goals: reduction of stress and anxiety to avoid precipitation of thyroid storm; stress= increased T3 and T4 \* The patient must be EUTHYROID at time of surgery, so thioamides are administered to control hyperthyroidism. \* lodide (SSKI or Lugol\'s solution) - to increase firmness of thyroid gland decrease its size and to reduce its vascularity. \* An attempt is made to counteract the effects of hypermetabolism by maintaining a restful and therapeutic environment and by providing a nutritious diet. **PRIORITY AFTER SURGERY** **A - Airway** \- Note for laryngeal stridor, noisy breathing, hoarseness or weak voice \- Endrotracheal set at bedside **B- Breathing** **C - Circulation** \- Place the patient in semi-Fowler\'s position, with the head elevated and supported by pillows; avoid flexion of neck. \* Neutral head and neck alignment \* HOB 30-45 degrees, NOT SUPINE nor high fowlers- putting client on high fowlers can cause flexing of the neck which can affect sutures and can lead to bleeding; supine can cause hyperexntension of neck \* No flexing or extending neck \- Move the patient carefully; provide adequate support to the head so that no tension is placed on the sutures. (neck splint) \* Monitor vital signs frequently, watching for tachycardia and hypotension that indicates hemorrhage (most likely between 12 and 24 hours postoperatively). \* Observe bleeding at sides and back of the neck, and anteriorly, when the patient is in dorsal position. \* Watch for repeated clearing of the throat or for complaint of smothering or difficulty swallowing, which may be early signs of hemorrhage.- blood is accumulating **C- Calcium low** (caused by removal or disturbance of parathyroid glands) \* Signs of hypocalcemia are watched for numbness and tingling sensation irritability, twitching, spasms of hands and feet. \- Calcium levels are monitored. \- If in 48 hours, level falls below 7 mg/100 mL (3 mEq/L), I. V. calcium (gluconate, lactate) replacement is given. \- I.V. calcium is used cautiously in patients who have renal disease. \* Watch for irregular breathing, swelling of the neck, and choking \- other signs pointing to the possibility of hemorrhage and tracheal compression. \* Reinforce dressing if indicated. \* Ask the client to speak every hour. Be alert for voice changes, which may indicate damage to laryngeal nerve. \* Monitor temperature as hyperthermia is an initial sign of THYROID CRISIS. \* Advise clients to support the neck with interlaced fingers when getting up from bed. **Exophthalmos** \* Encourage use of dark glasses when awake and taping the eyelids shut during sleep as needed. \* Eyepatch. \* Moisten conjunctiva often with isotonic eye drops. \* Elevate the head of the bed and restrict salt intake if indicated. \* Methylcellulose drops. **Patient Education and Health Maintenance** \* Instruct the patient as follows: \- When to take medications. \- Signs and symptoms of insufficient and excessive medication. \- Necessity of having blood evaluations periodically to determine thyroid levels. \- Signs of agranulocytosis (fever, sore throat, upper respiratory infection) or rash, fever, urticaria, or enlarged salivary glands caused by thioamide toxicity.  **Diet** \* HIGH CALORIES (4000-5000 PER DAY \- body is undergoing proteilysis and lipolysis \* HIGH PROTEIN AND CARBS \* FREQUENT MEALS AND SNACKS (6-8 DAY) \* NO high fiber, NO caffeine, NO spicy food **HYPOTHYROIDISM** \* A state of insufficient thyroid hormone \* The metabolic activity of all cells of the body decreases \* T4 and T3 are low \* negative feedback effect: TSH is elevated **Etiology**: **\* Primary Hypothyroidism**: caused by pathologic changes within the thyroid gland itself \- iodine deficiency \- Autoimmune thyroiditis/anti-thyroid
antibodies (Hashimoto\'s Disease); thyroglobulin and peroxidase antibodies which are contained in the thyroid gland causing damage \- Thyroidectomy \- Radioactive iodine therapy \- Antithyroid medication therapy **\* Secondary hypothyroidism**: results from pathologic changes in the pituitary gland - thyroid is not being stimulated by the pituitary to produce hormones \- Tumor (Pituitary Adenoma) **\* Tertiary hypothyroidism**- caused by disorders of the hypothalamus; decreaed TRH causes decreased TSH and T3 & T4 \- Congenital - maternal jodine defciency **Laboratory and Diagnostic Study Findings** \* Decreased T4 and T3 levels \* Serum TSH test reveals increased TSH \* Serum antibody test reveals elevated cholesterol and CK **CLINICAL MANIFESTATIONS** \- Low T3 and T4; low metabolic activity \* Sluggishness, lethargy, fatigue and exercise intolerance \* Mood and Memory impairment (depression,apathy, decreased concentration and attentiveness, slower thinking and speech) \* Cold intolerance - low core body temp. \* Bradycardia, hypotension \* Constipation \* Weight gain (slow metab) \- high cholesterol= increased triglycerides \* Menstrual irregularities, infertility, decreased libido \* Dry skin, brittle nails, dry hair, hair loss \* Generalized puffiness and periorbital and facial edema; masked appearance (myxedema; caused by proliferation) \* Possible goiter (constant stimulation of the thyroid gland) **MYXEDEMA** \- dermatologic changes that occur in hypothyroidism \- The slowing of metabolic processes may lead to the accumulation of mucopolysaccharides (glycosaminoglycan hyaluronic acid) in the skin - WAXY APPEARANCE \- binds with water \- responsible for the thickening of the tongue and the laryngeal and pharyngeal mucous membranes, which results in thick slurred speech and hoarseness \*in post thyroidectomy- patients are asked to talk to assess laryngeal function **CRETINISM** \* lack of thyroxine from birth; T4 \* or before birth \* could be from lack of thyroid gland \* or lack of iodine in mother \* severe and irreparable mental defects \* stunted growth \* reduced growth and function of many organs **Management** \* Levothyroxine (Synthroid) -T4 \* Liothyronine (Cytomel)- T3 \- Raises metabolic rate, promotes gluconeogenesis, increase use of stored glycogen, stimulates protein synthesis and affects protein and carbohydrate metabolism and cell growth LIOTHYRONINE \- expensive; short acting \- Used in emergency cases  **NURSING INTERVENTION** \* ADMINISTER MEDICATIONS - thyroid replacement \* PATIENT EDUCATION (for T4- LEVOTHYROXIN) \- L - Life Long+ long, slow onset (3-4 weeks) \- E - Early morning, empty stomach x 1 daily (not at night to avoid insomnia) \- V - Very Hyper (high HR, BP, Temp - increased metab rate); report agitation and confusion \- nOt to stop taking it abruptly - myxedema coma \- S- Safe for pregnant women \- Do not take within 4 hours of Gl medications \~ (Aluminum hydroxide, simethicone) -they decrease absorption of thyroid meds \* Assess temperature hourly, monitor
BP frequently, monitor F/E and glucose levels, monitor for mental status changes. \* Keep the client warm. \* Provide relief of constipation \* Institute respiratory assistance when necessary- deep breathing exercises; preparation of intubation set \* Administer fluids cautiously \* **Diet**: low calorie; low cholesterol and saturated fats \- Control of dietary intake to limit calories and reduce weight \* Implement infection-prevention measures \* Avoid food that inhibit thyroid secretion (turnips, cabbage, carrots, peaches, peas, strawberries, spinach) \* **AVOID**:- respiratory resistance \- Narcotics (morphine, Fentanyl) \- Sedatives (Benzodiazepines: Lorazepam) \* MONITOR FOR DEVELOPMENT OF MYXEDEMA COMA **MYXEDEMA COMA**: \- results from a persistently, SEVERELY low thyroid production **CAUSES**: can develop gradually over years or acutely in response to precipitating factors \- Illness (respiratory, urinary, cardiac etc.) among elderly women \- Stress \- Lithium and Amiodarone (inhibit thyroid hormone release) \- Sedative or OPIOID use \- require immediate interventions ***Myxedema coma*** \- severe hypothyroidism leading to decreased mental status, hypothermia, and other symptoms related to slowing of function in multiple organs. It is a medical emergency with a high mortality rate. \* Toxicity - antithyroid hormone \* Thyroidectomy \* Cold exposure \* Abrupt cessation of levothyroxine **Clinical Manifestations:** **SIGNS AND SYMPTOMS** \* Hypotension \* Hypoventilation - hypercapnia- CNS depression- coma state \* Hypothermia - COLD INTOLERANCE \* Bradycardia- affect cardiac output; affecting perfusion \* Hypoglycemia (decreased metabolic rate - dec. gluconeogenesis) \*type 1 & 2 DM should be tested for hypothyroidism \* Generalized edema \* Respiratory failure - respiratory acidosis \* Hyponatremia (due to decreasing blood flow- release of ADH- retention of water - dilutes the blood) \* Seizures, coma **Management** \* Maintain patent airway Mechanical ventilation (may be necessary) \- Place tracheostomy or endotracheal intubation set by bedside \* Administer IV fluids (normal or hypertonic saline) as prescribed. - both contain sodium \* Administer levothyroxine sodium, glucose intravenously as prescribed; \* Administer corticosteroids as prescribed until adrenal insufficiency has been ruled out.- corticosteroids enhance gluconeogenesis; too much corticosteroids also causes adrenal glands' function \*adrenal crisis when corticosteroids is stopped \* Administer glucose intravenously as prescribed. \* Monitor cardiovascular status. \* Cover hypothermic clients with regular blankets, NOT warming blankets. - causes peripheral vasodilation and aggravates hypotension then cardiovascular collapse