Endocrine Disorders

• Thyroid Gland and Parathyroid
• Adrenal Glands
• Anterior and Posterior Pituitary Glands

Thyroid gland produces 3 hormones

• thyroxine (T4)
• triiodothyronine (T3)
• thyrocalcitonin (calcitonin)

Secretion of T3 and T4 is regulated by

Anterior pituitary gland through a negative feedback system

When serum T3 and T4 decreases...

TSH is released by anterior pituitary. Stimulates thyroid gland to produce more hormone.

T3 and T4 affect all body systems by regulating...

 metabolism, energy production, use of fats, protein and carbohydrates, and fluid and electrolytes.

Calcitonin

Inhibits mobilization of calcium from bone and lowers blood calcium levels.

Thyroid hormones regulate...

• Energy metabolism

• Growth and Development

Disorders of the thyroid gland include:

• Enlargement
• Benign and Malignant nodules
• Inflammation
• Hyperfunctioning
• Hypofunctioning

Hyperthyroidism:

How it Happens

• T-cell lymphocytes become sensitized to thyroid antigens and stimulate B-cell lymphocytes to secrete auto-antibodies.

• Thyroid stimulating antibodies bind to and stimulate Thyroid Stimulating Hormone (TSH receptors of the thyroid). This increases production of thyroid hormone and cell growth.

Forms of Hypothyroidism

• Graves
• Toxic multinodular goiter (small benign nodule in thyroid gland that secretes thyroid hormone).
• Thyrotoxicosis factitia: chronic ingestion of thyroid hormone for thyrotropin suppression in patients with thyroid carcinoma, or from abuse of thyroid for weight loss.
• Functioning metatastic thyroid carcinoma
• TSH secreting pituitary tumor
• Subacute thyroiditis form virus induced inflammation
• Silent thyroiditis, self limiting

Hyperthyroidism

• Hyperactivity, increase and synthesis of thyroid hormones
• Thyrotoxicosis, clinical syndrome hypermetabolism form excess T4, T3.
• Graves disease (most common form, 75% cases) increase thyroxine (T4). Enlarges thyroid gland (goiter).
• Autoimmune (Graves).
• Enlarged thyroid and excess hormone
• Exacerbations and remissions
• May destroy thyroid and cause hypothyroidism

Hyperthyroidism Tests and DX

• Physical exam
• radioactive Iodine (131I)
• Thryoid scan
• Serum TSH level is usually low
• Free Thyroxine Index (FTI) and T3/ elevated
• Thyrotropin releasing hormone (TRH) stimulation test / the TSH fails to rise
• T3 and free T4 levels are usually high

Hyperthyroidism Clinical Picture

• Increases metabolism
• Increases tissue sensitivity tostimulation by SNS
• Opthalmopathy
• Graves disease (Thyrotoxicosis) increased T4, goiter, multisystem changes
• Exopthalmos, protrusion of eyeballs from orbits (impaired venous drainage to fat deposits and edema). Corneal ulcers and vision loss if lids don't close.

Nursing Assessment

• Hypermetabolic state
• Early stages: Weight loss, nervousness
• May exhibit many symptoms in advanced disease:

Increased appetite, weight loss, thirst, nausea, diarrhea, polyuria, sweating, insomnia, palpitations, dyspnea, muscle weakness, fatigue, chest pain, nevousness, heat intolerance, decreased libido, impotence, amenorrhea, emotional lability, personality changes

• Difficult to diagnose in elderly:

May present with anorexia, apathy, lassitude, depression, confusion, atrial fibrillation, heart failure.

Nursing Assessment

• Heat intolerance and sweating are common
• Agitation, rapid speech and movements, enlarged gland, hyperthermia.
• Exopthalmos
• Diaphoretic, edema, tachypnea
• Tachycardia, bounding pulse, murmurs, dysrhythmias
• Hyperflexia, fine tremors
• Muscle wasting, weight loss despite increased appetite, diarrhea
• Bruits over thyroid gland, Elevated systolic BP, widened pulse pressure, S3 heart sound

Hyperthyroidism Management

• Anti-thyroid drugs
• Thyroid hormone antagonists propylthiouricil (PTU), methimazole (Tapazole) to block thyroid hormone synthesis
• Beta-adrenergic blocker (propanolol (inderal)) until antithyroid drugs work treat SNS effects (tachyardia).
• Iodine (Potassium 131 I) to decrease thyroid gland's capacity for hormone production.
• Thyroidectomy
• Surgery is after anti-thyroid drugs achieve a euthroid state
• Lifelong medical supervision

Hyperthyroidism Nursing Interventions

• Administer meds as ordered and monitor
• Promote calm environment
• Minimize energy expenditure
• Nutritional support
• Assess mental status and safety
• Eye protection for exopthalmos (patches, lubricant)
• Monitor VS
• Prepare for surgery if needed

Thyroidectomy

• All or partial removal of thyroid

To treat hyperthyroidism, respiratory obstruction form goiter, thyroid cancer

• Preoperative drug regimen for euthyroid state to prevent thyrotoxicosis during surgery. Possible ECG to check heart
• Propythiouracil (PTU), or methimazole (Tapazole) given about 4 to 6 weeks before surgery
• Iodine 10-14 days before surgery to reduce the glands vascularity to prevent excess bleeding
• Propanolol (Inderal) to reduce excess sympathetic effects

Thyroidectomy Post Surgery

• Monitor for respiratory distress, laryngeal edema, (stridor or restlessness) Pt may need emergency tracheotomy.
• Monitor for bleeding and tracheal compression
• Watch for Thryroid storm
• Sudden and dangerous increase in thyroid hormone (pulse, respirations, and temperature increase rapidly)
• Assess for hypocalcemia (bones depleted of calcium form hyperthyroidism begin t oheal rapidly from the blood or if the parathyroid gland was damaged).

• Check for positive Chvostek's or Trousseau's sign, indicating neuromuscular irritability from hypocalcemia, Calcium glugonate for emergency IV administration

Thyroidectomy Post Surgery

• Patient teaching about taking prescribed thyroid medications regularly
• Watch for signs of both hyperthyroidism and hypothyroidism
• If the parathyroid gland was damaged, they may need to take calcium supplements.
• Keep incision site clean and dry, follow-up appointments, and serum thyroid hormone checks.

Thyroid Storm

• Thyrotoxic crisis
• Acute, rare condition with all hyperthyroid manifestations intensified.
• Life threatening emergency. Treatment successful if early
• Possible causes: Stressors (infection, trauma, surgery)
• Severe tachycardia, heart failure, shock, hyperthermia (up to 105.3 F), restlessness, agitation, hyperglycemia, sizures, abdominal pain, nausea, vomiting, diarrhea, delirium, coma.

Treatment for Thyroid Storm

• Drug therapy to reduce circulating thyroid.
• Supportive therapy
• Managing respiratory distress, monitor for dysrhythmias
• Fever: Use acetominophen, Aspirin is contraindicated because it releases thyroxine, cool baths
• Administer PTU (propylthioracil)
• Administer Inderal (propanolol)
• Administer IV fluids, prevent vascular collapse (loss from increased fluid excretion by kidneys or diaphoresis)
• Insulin (Hyperglycemia can occur from hypermetabolic state).
• Administer sodium iodide one hour after PTU (if given before PTU, it can worsen sx)
• Administer O₂ for increased O₂ demands of hypermetabolic state

Hypothyroidism

• From hypothalmic, pituitary, or thyroid insufficiency, or resistance to thyroid hormone.
• Can progress to life-threatening myxedema.
• Causes: autoimmune disease (Hasimoto's thyroiditis), overuse of anti-thyroid drugs, thyroidectomy, malfunction of pituitary, radiation