Objectives Thyroid Statistics Anatomy & Physiology of the Thyroid Gland Thyroid Hormones, Calcitonin & Iodine Thyroid Function Tests Thyroid Dysfunctions (Definition, Cause, Diagnosis, Treatment, Medical Management) Hypothyroidism & Hyperthyroidism Hypoparathyroidism & Hyperparathyroidism Thyroiditis Thyroid Cancer Case Study Conclusion
Thyroid Statistics Worldwide: estimated that 200 million people are affected by thyroid disease 1 in 10 Canadians suffer from some type of thyroid disease (Thyroid Foundation of Canada) 6,000 Canadians will be diagnosed with thyroid cancer. (Canadian Cancer Society)
Anatomy & Physiology of the Thyroid The thyroid gland is a small butterfly-shaped gland located in the anterior portion of the neck. It is the regulator of all body functions, with the major function being the production, storage, and release of the thyroid hormones, which are essential to all growth and metabolism.
Thyroid Hormones T3-Thyroxine T4-Tri-iodthyronine Actions: Influence every major organ system Control cellular metabolic activity Increase metabolic processes Help convert food into energy & heat Influence cellular replication Important in brain development Necessary for normal growth Increase body temperature
Thyroid Function Tests Thyroid Stimulating Hormone (TSH) Free Thyroxine (FT4) Thyroxine (T4) Tri-Iodothyronine (T3) The two tests most commonly used
Thyroxine (T4) & Tri-Iodothyronine (T3) T4 is one of the first tests performed to diagnose thyroid function and makes up nearly all of thyroid hormone. T3 is a measurement used to primarily diagnose hyperthyroidism. Only 7-10% of thyroid hormone is composed of T3.
Hypothyroidism Thyroid gland becomes underactive and does not produce enough thyroid hormones. Deficient levels of thyroid hormone can range from mild (subclinical forms) to myxedema (advanced, severe symptoms). Primary: due to the malfunctioning of the thyroid gland itself. Secondary: due to malfunctioning of pituitary gland, thyroid is not being stimulated by pituitary to produce hormones. Most commonly affects women aged 30-60
Hypothyroidism: Causes Hashimoto’s disease Autoimmune disorder attacking the thyroid gland, damaging it resulting in underproduction of thyroid hormones. Results in inflammation of the thyroid and possibly goiter Other causes: Radiation of the head and neck Patients with previous hyperthyroidism who have been treated with anti-thyroid medications/surgery
Hypothyroidism: S&S Early Signs and Symptoms Usually non-specific Extreme fatigue Hair loss, brittle nails, dry skin, numbness/tingling of fingers.
Myxedema Severe/prolonged hypothyroidism leads to myxedema Myxedema: physiological reaction to lack of sufficient thyroid hormone Accumulation of mucopolyshaccharides in subQ tissues Subnormal temp & pulse Thickened skin Mental processes dulled, enlarged tongue, slow speech Cognitive changes similar to dementia Cardiovascular changes: inc. cholesterol, atherosclerosis, coronary artery disease, poor left ventricular function
Myxedema Coma If prolonged/untreated Most extreme and severe stage of hypothyroidism Pt is hypothermic and unconscious High mortality rate
Medical Management Restore metabolic state with hormone replacement therapy Synthetic Levothyroxine (Synthroid) Prevention of Cardiac Dysfunction
Nursing Management Modifying activity Monitor Physical Status Promote Physical comfort Provide emotional Support Remember: administer medications with caution as metabolic rates slowed. ** Opioids, anesthetic agents**
Hyperthyroidism Thyroid gland produces an excess of thyroid hormones More common in women Most frequent between the ages of 20-40 Thyrotoxicosis-hypermetabolic state caused by excess T3 or T4
Trousseau’s Sign A carpal spasm induced by inflating a blood pressure cuff above the systolic pressure for a few minutes.
Chvostek’s Sign A contraction of facial muscles in response to a light tap over the facial nerve in front of the ear.
Hyperparathyroidism An excess secretion of parathyroid hormone (PTH) from the parathyroid gland Primary-benign neoplasm or a single adenoma, malignant tumor (rare), hyperplasia Secondary-compensatory response to other causes of hypocalcemia
Hyperparathyroidsim Manifestations Loss of appetite, need more sleep, forgetfulness Complications Renal failure, pancreatitis, cardiac changes, fractures Diagnosis Blood tests, urine tests, bone mineral density test, diagnostic imaging
Thyroiditis There are three types of thyroiditis, each type characterized by inflammation, fibrosis or lymphocytic infiltration. Can cause thyrotoxicosis, hypothyroidism or both Acute Thyroiditis Subacute Thyroiditis (2 types) Chronic Thyroiditis (Hashimoto’s disease)
Thyroid Cancer Accounts for 90% of endocrine malignancies. 47,000 new cases are diagnosed each year. Papillary Adenocarcinoma (most common) Follicular Adenocarcinoma Medullary Anaplastic Thyroid lymphoma Treatment: surgical removal, radioactive iodine used to eradicate residual affected thyroid tissue, thyroid replacement therapy (lifelong)
Case Study Mrs. Graves is a 26 year-old female who presented to your clinic describing feelings of nervousness and irritability and difficulty sleeping at night. She has lost 15lbs in the last two months even though her eating & exercise patterns have not changed. Vitals signs are: BP 142/60, P 106, R 22, T 36.9. Your physical exam reveals that she appears thin, restless & tearful. Her hair is thinning at the temples, her thyroid is enlarged & her eyes are protruding.
References Canadian Cancer Society. (2014). Anatomy and physiology of the thyroid gland. Retrieved from http://www.cancer.ca/en/cancer-information/cancer-type/thyroid/anatomy-and-physiology/?region=bc http://www.cancer.ca/en/cancer-information/cancer-type/thyroid/anatomy-and-physiology/?region=bc Endocrine Web. (2012). How Your Thyroid Works: “A Delicate Feedback Mechanism”. Retrieved from http://www.endocrineweb.com/conditions/thyroid/how-your-thyroid-works Lewis, S. L., Heitkemper, M. M., Dirksen, S. R., O’Brien, P.G.,& Bucher, L. (2010). Medical-surgical nursing in Canada: Assessment and management of clinical problems Toronto: Elsevier Mosby Mayo Clinic. (2012). Hyperthyroidism (overactive thyroid). Retrieved from http://www.mayoclinic.org/diseases- conditions/hyperthyroidism/basics/definition/con-20020986 Mayo Clinic. (2014). Hyperparathyroidism. Retrieved from http://www.mayoclinic.org/diseases- conditions/hyperparathyroidism/basics/definition/con-20022086 National Instituites of Health. (2014). Iodine: Fact Sheet for Health Professionals. Retrieved from http://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/#h3 http://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/#h3 Pike-MacDonald, S. (2013). Mosby’s Canadian manual of diagnostic and laboratory tests. Toronto, ON: Elsevier Thyroid Foundation of Canada. (2014). Hyperthyroidism (Thyrotoxicosis). Retrieved from http://www.thyroid.ca/thyrotoxicosis.php http://www.thyroid.ca/thyrotoxicosis.php