Diseases and Disorders
Hyperthyroidism
General
DRG Category: 644
Mean LOS: 4.3 days
Description MEDICAL Endocrine Disorders With Complication or Comorbidity
Introduction
Hyperthyroidism is a condition caused by excessive overproduction of thyroid hormone by the thyroid gland. The thyroid hormones (triiodothyronine [T3] and thyroxine [T4]), produced in the thyroid gland under the control of thyroid-stimulating hormone (TSH), regulate the body’s metabolism. Sustained thyroid hormone overproduction, therefore, causes a hypermetabolic state that affects most of the body organs, such as the heart, gastrointestinal tract, brain, muscles, eyes, and skin.
The seriousness of the disease depends on the degree of hypersecretion of the thyroid hormones. As the levels of thyroid hormones rise, the risk of life-threatening cardiac problems becomes progressively greater. The most common form of hyperthyroidism is called Graves disease or thyrotoxicosis. Graves disease is associated with hyperthyroidism, eye disorders, and skin disorders, and when uncontrolled, vital organs are stressed to their capacity. It is also associated with many autoimmune diseases such as diabetes mellitus, breast cancer, Addison disease, systemic lupus erythematosus, rheumatoid arthritis, myasthenia gravis, and pernicious anemia. Risk factors include tobacco use, high iodine intake, stress, and use of sex steroids.
Cardiac stress from increased myocardial oxygen requirements can lead to serious cardiovascular complications, such as systolic hypertension, life-threatening dysrhythmias, or heart failure. Large goiters can cause pressure on the neck and trachea, which can result in respiratory distress. Ophthalmopathy can result in corneal ulceration and loss of vision. Metabolic hyperactivity can cause high levels of anxiety, insomnia, and psychoses. The most severe form of hyperthyroidism is thyrotoxic crisis, known also as thyroid storm or thyrotoxicosis. This condition, which occurs when the body can no longer tolerate the hypermetabolic state, is a nursing and medical emergency and is fatal if not treated. Thyroid storm may be precipitated by a physiological stressor such as diabetic ketoacidosis, infection, trauma, or surgery.
Causes
Graves disease has an autoimmune derivation and is caused by circulating anti-TSH autoantibodies that displace TSH from the thyroid receptors and mimic TSH by activating the TSH receptor to release additional thyroid hormones. Graves disease is also associated with Hashimoto disease, a chronic inflammation of the thyroid gland that usually causes hypothyroidism but can also cause symptoms similar to those of Graves disease.
Thyrotoxicosis has several different pathophysiological causes, including autoimmune disease, functioning thyroid adenoma, and infection.
Genetic Considerations
Hyperthyroidism has a strong genetic component, with heritability estimated at 40% to 60%. Mutations in the thyroid-stimulating hormone receptor gene (TSHR) cause a nonautoimmune form of hyperthyroidism that is inherited in an autosomal dominant manner. The autoimmune form of hyperthyroidism, Graves disease, is caused by mutations in several genes and follows either an autosomal recessive or X-linked inheritance pattern. Loci that have been linked with Graves disease include chromosome 6p11, CTKA4 on 2q33, AITD1, CTLA4, GRD1, GRD2, GRD3, HT1, and HT2. Other loci and the human leukocyte antigen (HLA) region types are also linked with Graves disease.
Sex Life Span Considerations
Hyperthyroidism is more frequently found in women than in men, and some experts suggest that the hormone cycles of women may in some way affect the incidence of thyroid disease. Although it can affect all ages, it is most typically diagnosed in 20- to 40-year-olds and is unusual in children, teenagers, and people over age 65 years. When hyperthyroidism occurs in older adults, their symptoms may be more subtle than those of younger persons, and the classic signs may even be absent. Occasionally, an older person with hyperthyroidism has apathy or withdrawal instead of the more typical hypermetabolic state.
Health Disparities Sexual/Gender Minority Health
White, Asian, and Hispanic persons have a slightly higher prevalence of hyperthyroidism than do Black persons. Sexual and gender minority status has no known effect on the risk of hyperthyroidism.
Global Health Considerations
Hyperthyroidism is present in people of all countries. Areas of the world that have iodine deficiency place people at risk for both hyperthyroidism and hypothyroidism. Countries with insufficient iodine include Eastern Europe, Russia, and parts of Africa. Highest prevalence occurs in Brazil, China, India, Great Britain, and Northern Africa.
Assessment
History
Ask patients about their medical history and if they have experienced nervousness, anxiety, or hyperactivity. Often, patients report intolerance to heat, excessive perspiration, and increased appetite accompanied by weight loss. Complaints of abdominal cramping and frequent bowel movements are customary. Patients may also describe discomfort when wearing clothing or jewelry that is close fitting at the neckline as well as generalized muscular weakness and increased fatigue. Physical exertion may cause chest pain, shortness of breath, or both. They may have a history of heart failure or cardiac dysrhythmias. A female patient may report oligomenorrhea (scanty or infrequent menses), and all patients might experience decreased libido. Ask patients if they use tobacco products or have high levels of stress in their life.
Determine if there is a family history of autoimmune disease or thyroid disease. Take a drug history to determine the use of iodides (oral contraceptives, contrast media) that may cause falsely elevated serum thyroid hormone levels. Determine if they lived in an area of the world that is iodine deficient. Similarly, severe illness, malnutrition, or the use of aspirin, corticosteroids, and phenytoin sodium may cause a false decrease in serum thyroid hormone levels.
Physical Examination
The most common symptoms are due to hypermetabolism, such as anxiety, diaphoresis, nervousness, and palpitations. The patient may have a short attention span and fine hand tremors or shaky handwriting. Note an increased resting pulse, a widened pulse pressure, or hypertension. The skin may have a sheen of perspiration or be salmon colored.
Stand behind the patient and palpate the thyroid gland at rest and during swallowing to note the size, tenderness, and nodularity. Remember that excessive palpation of the thyroid gland can precipitate thyroid storm; therefore, palpate gently and only when necessary. You may also hear a bruit when you auscultate the thyroid gland over the lateral lobes. Exophthalmos, bulging of the eye resulting in larger amounts of visible sclera, is often quite noticeable; a fixed stare because of the presence of fluid behind the eyeball and periorbital edema are also common. In patients who have had Graves disease for several years, there may be changes in the skin, such as raised and thickened areas over the legs or feet and hyperpigmentation and itchiness. Patients often exhibit fine, thin hair and fragile nails. Patients with thyroid storm have a racing heart, high fever, profound diaphoresis, diarrhea, severe dehydration, shaking, agitation, confusion, and coma.
Psychosocial
Well before a formal diagnosis, the patient may be aware that something is seriously wrong and report increased anxiety or nervousness, insomnia, and early awakening from sleep. The anxiety is often heightened by symptoms of the disease such as angina and the sense of loss of control over one’s body.
Diagnostic Highlights
| Test | Normal Result | Abnormality With Condition | Explanation |
|---|---|---|---|
| TSH assay | In most healthy patients, TSH values are 0.4-4.2 mU/L | Decreased so that values may be unmeasurable | Elevation of thyroid hormones; decreased TSH secretion by negative feedback |
| T4 radioimmunoassay | 5.5-12.5 mcg/dL | Elevated | Reflects overproduction of thyroid hormones; monitors response to therapy |
| T3 radioimmunoassay | 70-204 ng/dL | Elevated | Reflects overproduction of thyroid hormones |
Other Tests: Tests include 24-hour radioactive iodine uptake, thyroid autoantibodies, antithyroglobulin, nuclear thyroid scan, and electrocardiogram.
Primary Nursing Diagnosis
Diagnosis: Decreased activity tolerance related to increased metabolism as evidenced by exhaustion, palpitations, and/or fatigue
Outcomes: Activity tolerance; Energy conservation; Knowledge: Disease process; Knowledge: Medication; Endurance; Nutritional status; Symptom severity
Interventions: Energy management; Exercise promotion; Nutrition management; Medication management; Vital signs monitoring
Planning and Implementation
Collaborative
Most patients are diagnosed and treated on an outpatient basis. Symptoms are managed with oral hydration and beta-blockers for relief of neurological and cardiovascular symptoms. The goal of treatment is to return the patient to the euthyroid (normal) state and to prevent complications. Graves disease is treated pharmacologically (see Pharmacologic Highlights). Radioactive iodine (131I) is given for two purposes: for diagnosing imaging in low doses and for therapeutic destruction of the thyroid gland in larger doses. Radioactive iodine is considered the definitive and most common treatment, but it is not without risks. The principal disadvantage is the potential for hypothyroidism because 40% to 70% of patients treated with 131I develop hypothyroidism within 10 years after treatment. Other complications include parathyroid damage and exacerbation of hyperthyroidism. Surgical treatment with thyroidectomy is no longer the preferred choice of therapy for Graves disease but is an alternative therapeutic approach in some situations. In particular, it is used for patients who cannot tolerate antithyroid drugs, have significant ophthalmopathy, have large goiters, or cannot undergo radioiodine therapy.
If thyroid storm is suspected, emergency treatment needs to be instituted immediately. Patients may need cardiac monitoring, intubation and mechanical ventilation with supplemental oxygen, and IV fluids. The patient requires antithyroid medications and may receive IV corticosteroids and beta-adrenergic medications.
Pharmacologic Highlights:
| Medication or Drug Class | Dosage | Description | Rationale |
|---|---|---|---|
| Propylthiouracil (PTU) | Initial PTU: 300-400 mg/day PO divided tid; not to exceed 1,200 mg/day; maintenance: 100-300 mg/day PO | Antithyroid agent | Returns the patient to the euthyroid (normal) state; inhibits use of iodine by thyroid gland; blocks oxidation of iodine and inhibits thyroid hormone synthesis |
| Methimazole (Tapazole) | Initial: 15 mg/day for mild hyperthyroidism; 30-40 mg/day for moderately severe hyperthyroidism; 60 mg/day for severe hyperthyroidism | Antithyroid agent | Returns the patient to the euthyroid (normal) state; inhibits use of iodine by thyroid gland |
Other Drugs: Beta-adrenergic blockers, corticosteroids for vision threatening opthalmopathy, radioactive iodine
Independent
Nursing interventions center on ongoing monitoring, protecting the patient from injury, reducing stress, and initiating teaching. Patients with exophthalmos or other visual problems might be more comfortable wearing sunglasses or eye patches to protect the eyes from light. Report any changes in visual acuity to the physician and use artificial tears to lubricate the eyes.
Encourage patients to follow the medication regimen and reassure them while waiting for it to take effect. To determine the response to treatment and to prevent thyroid storm, assess the cardiovascular status, fluid and diet intake and output, daily weights, bowel elimination, and the ability of the patient to perform activities of daily living without excessive fatigue. Reassure the patient’s family that the patient’s mood swings, nervousness, or anxiety will diminish as treatment continues. If the patient or family requires additional support, ask a clinical nurse specialist or mental health counselor to see the patient or family. Note that extreme anxiety of the undiagnosed or uncontrolled patient makes patient education difficult for all concerned. If you recognize the patient’s inability to maintain long cognitive or physical attention spans, you will have better success at patient education. One useful strategy is to ensure that significant others are present during all teaching sessions.
Evidence Based Practice Health Policy
Pan, Y., Xie, Q., Zhang, Z., Dai, Y., Lin, L., Quan, M., Guo, X., Shen, M., & Zhao, S. (2020). Association between overt hyperthyroidism and risk of sexual dysfunction in both sexes: A systematic review and meta-analysis. Journal of Sexual Medicine, 17, 2198-2207. [PMID:32800738]
- The authors conducted a systematic review and meta-analysis using electronic databases to explain the association between overt hyperthyroidism and the risk of sexual dysfunction. They located seven relevant studies.
- Overt hyperthyroidism led to significant sexual dysfunction in both sexes. Men and women with overt hyperthyroidism were at over twofold higher risk of sexual dysfunction than the general population. Women had issues with arousal, lubrication, orgasm, and sexual satisfaction, whereas men had issues with ejaculation, erectile dysfunction, and desire. The authors concluded that sexual health consequences may occur as a result of hyperthyroidism.
Documentation Guidelines
- Physical findings: Cardiovascular status (resting pulse, blood pressure, presence of angina or palpitations), bowel activity, edema, condition of skin, activity tolerance
- Physical findings: Hypermetabolism, eye status, heat intolerance, level of hydration, activity level
- Response to medications, skin care regimen, nutrition, body weight, comfort
- Psychosocial response to changes in bodily function, including mental acuity, behavioral patterns, emotional stability
Discharge and Home Healthcare Guidelines
DISEASE PROCESS Provide a clear explanation of the role of the thyroid gland, the disease process, and the treatment plan. Explain possible side effects of the treatment. Ensure that the patient understands eye care.
MEDICATIONS Be sure the patient understands all medications, including the dosage, route, action, adverse effects, and need for any laboratory monitoring of thyroid medications. If the patient is taking propylthiouracil or methimazole, encourage the patient to take the medications with meals to limit gastric irritation. If the patient is taking an iodine solution, mix it with milk or juice to limit gastric irritation and have the patient use a straw to limit the risk of teeth discoloration.
COMPLICATIONS Have the patient report any signs and symptoms of thyrotoxicosis immediately: rapid heart rate, palpitations, perspiration, shakiness, tremors, difficulty breathing, nausea, and vomiting. Teach the patient to report increased neck swelling, difficulty swallowing, or weight loss.
