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Endocrine Problems

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University of Toronto Scarborough
Biological Sciences
Stephen Reid

Chapter 50: Endocrine Problems ACROMEGALY  Acromegaly results from excess secretion of growth hormone (GH).  It is a rare condition of bone and soft tissue overgrowth.  Bones increase in thickness and width but not length.  Manifestations include enlargement of hands and feet, thickening and enlargement of face and head bony and soft tissue, sleep apnea, signs of diabetes mellitus, cardiomegaly, and hypertension.  Treatment focuses on returning GH levels to normal through surgery, radiation, and drug therapy. The prognosis depends on age at onset, age when treatment is initiated, and tumor size.  Nursing care for surgical patients postoperatively includes avoidance of vigorous coughing, sneezing, and straining at stool to prevent cerebrospinal fluid leakage from where the sella turcica was entered.  After surgery with a transsphenoidal approach, the head of the bed is elevated to a 30- degree angle at all times, and neurologic status is monitored. Mild analgesia is used for headaches, and toothbrushing is avoided for at least 10 days.  If hypophysectomy is done or the pituitary is damaged, antidiuretic hormone (ADH), cortisol, and thyroid hormone replacement must be taken for life. Patient teaching is essential with hormone replacement therapy. HYPOPITUITARISM  Hypopituitarism is rare, and involves a decrease in one or more of the pituitary hormones: o The anterior pituitary gland secretes adrenocorticotrophic hormone (ACTH), thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), GH, and prolactin. o The posterior pituitary gland secretes ADH and oxytocin.  Most deficiencies associated with hypopituitarism involve GH and gonadotropins (e.g., LH, FSH) due to a pituitary tumor. SYNDROME OF INAPPROPRIATE ANTIDIURETIC HORMONE  Syndrome of inappropriate antidiuretic hormone (SIADH) results from an overproduction or oversecretion of ADH.  SIADH results from abnormal production or sustained secretion of ADH and is characterized by fluid retention, serum hypoosmolality, dilutional hyponatremia, hypochloremia, concentrated urine in presence of normal or increased intravascular volume, and normal renal function.  The most common cause is lung cancer.  Treatment is directed at underlying cause, with a goal to restore normal fluid volume and osmolality. Fluid restriction results in gradual, daily weight reductions, progressive rise in serum sodium concentration and osmolality, and symptomatic improvement. With chronic SIADH, the patient must learn self-management. DIABETES INSIPIDUS  Diabetes insipidus (DI) is associated with deficiency of production or secretion of ADH or decreased renal response to ADH.  Decreases in ADH cause fluid and electrolyte imbalances due to increased urinary output and increased plasma osmolality.  Depending on the cause, DI may be transient or chronic lifelong condition.  Types of DI include: o Central DI (or neurogenic DI) occurs when an organic lesion of the hypothalamus, infundibular stem, or posterior pituitary interferes with ADH synthesis, transport, or release. o Nephrogenic DI occurs when there is adequate ADH, but a decreased kidney response to ADH. Lithium is a common cause of drug-induced nephrogenic DI. Hypokalemia and hypercalcemia may also lead to nephrogenic DI. o Psychogenic DI is associated with excessive water intake, caused by lesion in thirst center or by psychosis.  DI is characterized by polydipsia and polyuria.  If oral fluid intake cannot keep up with urinary losses, severe fluid volume deficit results as manifested by weight loss, constipation, poor tissue turgor, hypotension, and shock.  Severe dehydration and hypovolemic shock may occur.  Treating the primary cause is central to management. Therapeutic goal is maintenance of fluid and electrolyte balance.  Nursing care includes early detection, maintenance of adequate hydration, and patient teaching for long-term management. GOITER  Goiter is thyroid gland hypertrophy and enlargement caused by excess TSH stimulation, which can be caused by inadequate circulating thyroid hormones.  Goiter is also found in Graves’ disease.  TSH and T4 levels are measured to determine if goiter is associated with hyperthyroidism, hypothyroidism, or normal thyroid function.  Thyroid antibodies are measured to assess for thyroiditis.  Treatment with thyroid hormone may prevent further thyroid enlargement.  Surgery to remove large goiters may be done. THYROID NODULES  A thyroid nodule, a palpable deformity of the thyroid gland, may be benign or malignant.  Benign nodules are usually not dangerous, but can cause tracheal compression if they become too large.  Malignant tumors of thyroid gland are rare.  A major sign of thyroid cancer is presence of hard, painless nodule or nodules on enlarged thyroid gland.  Surgical tumor removal is usually indicated with cancer.  Procedures include unilateral total lobectomy with removal of isthmus to total thyroidectomy with bilateral lobectomy.  Radiation therapy may also be indicated.  Nursing care for thyroid tumors is similar to care for patient who has undergone thyroidectomy. THYROIDITIS  Thyroiditis is an inflammatory process in the thyroid gland.  Subacute and acute forms of thyroiditis have abrupt onset, and the thyroid gland is painful.  Chronic autoimmune thyroiditis (Hashimoto’s thyroiditis) can lead to hypothyroidism.  Hashimoto’s thyroiditis is a chronic autoimmune disease in which thyroid tissue is replaced by lymphocytes and fibrous tissue. It is most common cause of goiterous hypothyroidism.  Recovery may be complete in weeks or months without treatment. HYPERTHYROIDISM  Hyperthyroidism is thyroid gland hyperactivity with sustained increase in synthesis and release of thyroid hormones.  Thyrotoxicosis refers to physiologic effects or clinical syndrome of hypermetabolism resulting from excess circulating levels of T4, T3, or both.  Hyperthyroidism and thyrotoxicosis usually occur together as in Graves’ disease.  The most common form of hyperthyroidism is Graves’ disease.  Other causes include toxic nodular goiter, thyroiditis, exogenous iodine excess, pituitary tumors, and thyroid cancer. Graves’ Disease  Graves’ disease is an autoimmune disease marked by diffuse thyroid enlargement and excessive thyroid hormone secretion.  Factors such as insufficient iodine supply, infection, and stressful life events may interact with genetic factors to cause Graves’ disease.  Manifestations relate to the effect of thyroid hormone excess.  When thyroid gland is large, a goiter may be noted, and auscultation of thyroid gland may reveal bruits.  A classic finding is exophthalmos, a protrusion of eyeballs from the orbits.  Treatment options are antithyroid medications, radioactive iodine therapy, and subtotal thyroidectomy. Thyrotoxic Crisis  Thyrotoxic crisis, also known as thyroid storm, is an acute, rare condition in which all hyperthyroid manifestations are heightened.  Although it is a life-threatening emergency, death is rare when treatment is vigorous and initiated early.  Manifestations include severe tachycardia, shock, hyperthermia, seizures, abdominal pain, diarrhea, delirium, and coma.  Treatment focuses on reducing circulating thyroid hormone levels by drug therapy. HYPOTHYROIDISM  Hypothyroidism is one of most common medical disorders.  It results from insufficient circulating thyroid hormone.  This condition may be primary (related to destruction of thyroid tissue or defective hormone synthesis), or secondary (related to pituitary disease with decreased TSH secretion or hypothalamic dysfunction with decreased thyrotropin-releasing hormone [TRH] secretion).  Hypothyroidism also can be t
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