Chapter 36

Pituitary Tumors

• Etiology and Pathophysiology

  • Usually a benign pituitary adenoma.

• Signs and Symptoms

  • Local Symptoms:

    • Headaches (HA) from tumor pressure.

    • Visual disturbances, possible blindness.

  • Systemic Symptoms:

    • Personality changes, weakness, fatigue, vague abdominal pain.

• Diagnosis:

  • Complete history and physical examination.

  • Magnetic Resonance Imaging (MRI).

  • High-resolution Computed Tomography (CT) with contrast media.

• Treatment:

  • Hormone therapy, irradiation, surgery (hypophysectomy).

Transsphenoidal Surgical Approach for Hypophysectomy

• Types:

  • Endoscopic Binostril Approach

  • Endoscopic Uninostril Approach

• Postoperative Nursing Management:

  • Position patient in semi-Fowler's position.

  • Monitor for changes in vision, mental status, consciousness, or strength.

  • Observe for symptoms of diabetes insipidus: thirst, frequent urination, dry mouth.

  • Nasal packing and patient teaching.

Hyperfunction of the Pituitary Gland

• Etiology and Pathophysiology:

  • Pituitary adenoma may increase hormone release.

  • Stress and pregnancy can also cause increased hormone release.

• Signs and Symptoms:

  • Gigantism in children.

  • Acromegaly in adults.

• Treatment:

  • Removal of pituitary adenoma.

Hypofunction of the Pituitary Gland

• Etiology and Pathophysiology:

  • Most common cause is a tumor.

  • Autoimmune disorders, infections, or destruction of the pituitary gland.

  • Sheehan syndrome due to postpartum hemorrhage.

  • Decrease in growth hormone and gonadotropins.

• Signs and Symptoms:

  • With tumor: HA, visual changes, anosmia, seizures.

  • Other symptoms depend on involved hormone.

• Diagnosis:

  • History and physical examination.

  • Levels of pituitary hormones.

  • MRI and CT.

• Treatment and Nursing Management:

  • Hormone replacement, surgery, radiation.

  • Patient teaching.

Diabetes Insipidus

• Etiology and Pathophysiology:

  • Central DI: Linked to brain tumors, head injury, neurosurgery, CNS infections.

  • Nephrogenic DI: Caused by drug therapy (lithium) or kidney disease.

  • Dispogenic DI: Due to excessive water intake (often seen in schizophrenia).

• Signs and Symptoms:

  • Diuresis.

  • Thirst, weakness, fatigue (often from nocturia).

  • Deficient fluid volume, signs of shock, CNS manifestations.

• Diagnosis:

  • Complete history and physical examination.

  • Urine and plasma osmolality, urine specific gravity.

• Treatment and Nursing Management:

  • Replacement of fluid and electrolytes, hormone therapy.

  • Early detection, maintenance of fluid and electrolyte balance, patient education.

  • Baseline vital signs and weight monitoring.

  • Strict (hourly) intake and output monitoring.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

• Etiology and Pathophysiology:

  • Excessive ADH production leads to fluid retention.

• Signs and Symptoms:

  • Confusion, seizures, loss of consciousness, weight gain, edema.

  • Hyponatremia, muscle cramps, weakness, diminished urine output.

• Diagnosis:

  • Urine and serum osmolality test.

  • Blood urea nitrogen (BUN), hemoglobin, hematocrit, creatinine clearance.

• Treatment and Nursing Management:

  • Correct the underlying cause.

  • Restrict fluid intake to 500-1000 mL/day.

  • Administer sodium chloride, diuretics, and demeclocycline.

Goiter

• Etiology and Pathophysiology:

  • Enlarged thyroid gland due to iodine deficiency or lack of thyroid hormone.

• Signs and Symptoms:

  • Enlargement of the front of the neck.

• Treatment:

  • Iodine supplementation; elemental iodine or thyroid hormone can slow growth.

  • For procedures like goiter excision or thyroidectomy:

    • Monitor for symptoms indicating airway compromise (wheezing, 02 saturation drop, gasping).

Hyperthyroidism

• Etiology and Pathophysiology:

  • Primary hyperthyroidism (Grave's Disease or toxic goiter), secondary hyperthyroidism.

• Signs and Symptoms:

  • Early symptoms: weight loss, nervousness.

  • Later symptoms: weakness, insomnia, tremulousness, agitation, tachycardia, palpitations, exertional dyspnea, ankle edema, difficulty concentrating, diarrhea, increased thirst and urination, decreased libido, scanty menstruation.

• Diagnosis:

  • Clinical manifestations, heart rate while sleeping, electrocardiography, CT or MRI.

• Treatment and Nursing Management:

  • Use radioactive precautions.

  • Radioactive iodine and antithyroid drugs.

  • Patients should take medications on an empty stomach; effects may take 2-3 weeks.

Thyroid Crisis (Thyroid Storm)

• Etiology:

  • Caused by sudden increase in thryoxine output, often during thyroidectomy.

• Symptoms:

  • Temperature may rise to 106°F (41°C), rapid pulse (up to 200 BPM), rapid respirations, restlessness.

• Treatment:

  • Reduce temperature, administer cardiac drugs to slow heart rate, sedatives to reduce restlessness and anxiety.

  • Apply ice packs on the neck, armpits, between legs to lower temp.

Hypothyroidism

• Etiology and Pathophysiology:

  • Caused by inflammation of the thyroid or treatment of hyperthyroidism.

  • Congenital hypothyroidism (cretinism); underactivity due to pituitary or hypothalamus dysfunction.

• Signs and Symptoms:

  • In children: delayed physical and mental growth.

  • In adults: decreased appetite, increased weight (slow metabolic rate), lethargy, cold intolerance.

• Diagnosis:

  • Clinical signs and symptoms, serum level of thyroid hormones and TSH.

• Treatment:

  • Replacement thyroid hormone (Levothyroxine).

Thyroiditis

• Etiology and Pathophysiology:

  • Inflammation of the thyroid (acute, subacute, chronic).

  • Abrupt discontinuation of Levothyroxine can lead to myxedema coma.

  • Autoimmune thyroiditis (Hashimoto's thyroiditis).

• Signs and Symptoms:

  • Painless enlargement of the thyroid gland, symptoms of hyperthyroidism.

• Diagnosis:

  • Thyroid levels, needle biopsy.

• Treatment:

  • Acute: antibiotics, chronic: thyroid hormone replacement.

  • Surgery to remove part of the thyroid gland as needed.

Thyroid Cancer

• Etiology and Pathophysiology:

  • Most common type is papillary carcinoma (80%), occurring mainly in younger women.

  • Other cancers include follicular, medullary, and anaplastic carcinomas.

• Signs and Symptoms:

  • Presence of a thyroid nodule, voice changes, trouble breathing or swallowing, fatigue, depression, weight changes.

• Treatment:

  • Thyroidectomy; patient positioned in Fowler's for better breathing.

  • Radioactive iodine therapy; multiple drug therapies available for non-candidates.

Hypoparathyroidism

• Etiology and Pathophysiology:

  • Often due to atrophy or traumatic injury to the parathyroid glands, resulting in reduced calcium and phosphorus absorption.

• Signs and Symptoms:

  • Mild tingling, muscle cramps, irritability, tetany (involuntary muscle contractions), convulsions.

  • Positive Chvostek's and Trousseau's signs.

• Treatment:

  • Acute: IV calcium gluconate and vitamin D, oral or parenteral calcium salts.

  • Chronic: parathormone replacement therapy, vitamin D supplementation, and oral calcium salts.

Hyperparathyroidism

• Etiology and Pathophysiology:

  • Caused by excessive secretion of parathyroid hormone due to adenoma or hyperplasia of glands.

• Signs and Symptoms:

  • Dehydration, confusion, lethargy, arrhythmias, nausea, vomiting, weight loss, constipation, frequent urination, hypertension.

• Diagnosis:

  • Serum calcium and phosphate levels, serum parathyroid hormone, serum albumin.

• Treatment:

  • Primary: removal of adenoma.

  • Secondary: vitamin D supplements.

Pheochromocytoma

• Etiology and Pathophysiology:

  • Rare tumor of adrenal medulla that secretes catecholamines; usually benign but malignant in about 10% of cases.

• Signs and Symptoms:

  • Tachycardia, severe hypertension, profuse diaphoresis, headache, palpitations, nausea, weakness, pallor.

• Treatment:

  • Surgical removal.

  • Nursing management includes monitoring for hypertensive crisis, vital signs, and medications.

Adrenocortical Insufficiency (Addison's Disease)

• Etiology and Pathophysiology:

  • Primary or secondary insufficiency.

• Signs and Symptoms:

  • Vague early-stage symptoms; later stages present fluid and electrolyte imbalance, hypoglycemia.

• Diagnosis:

  • Blood cortisol and aldosterone levels, ACTH stimulation test, CT and MRI.

• Treatment:

  • Patients require lifelong medications: prednisone to replace glucocorticoids; fludrocortisone for mineralocorticoid aldosterone.

• Nursing Management:

  • Educate patients to manage stress and provide supportive care.

  • Prevent Addisonian crises and problems related to fatigue or orthostatic hypotension.

Excess Adrenocortical Hormone (Cushing's Syndrome)

• Etiology:

  • Excessive ACTH secretion by the pituitary causes Cushing's syndrome.

  • Can be due to pituitary secreting tumors or prolonged steroid therapy.

• Signs and Symptoms:

  • Buffalo hump, moon face, enlarged abdomen, thin extremities, easy bruising, impotence, hypertension, weakness.

• Diagnosis:

  • Plasma cortisol levels, ACTH levels, and 24-hour urine test for total cortisol.

• Treatment:

  • Microsurgery on the pituitary gland, adrenalectomy with glucocorticoid replacement, medications, and radiation.

• Nursing Management:

  • Help patients cope with systemic problems from the disorder.