Endocrine Exam Review Notes

Hyperpituitary Disorders

  • Anterior Pituitary Disorders

    • Excess in Growth Hormone: Leads to Acromegaly.
    • Cushing's Syndrome.

  • Posterior Pituitary Disorders

    • Syndrome of Inappropriate Antidiuretic Hormone (SIADH).

Pheochromocytoma

Pathophysiology
  • Catecholamine-producing tumors arising in the adrenal medulla.
  • These tumors produce, store, and release Epinephrine (EPI) and Norepinephrine.
Signs and Symptoms
  • Headache.
  • Sweating.
  • Palpitations/Tachycardia.
  • Hypertension (HTN).
  • Anxiety.
  • Nausea.
  • Tremors.
Treatment
  • Transsphenoidal Hypophysectomy.
    • What is it?: Surgery performed through the nose.
    • Post-operative Monitoring:
    • Postnasal drip.
    • Elevate Head of Bed (HOB).
    • No coughing, bending, or straining.
    • Avoid tooth brushing.

Hyperparathyroidism

Pathophysiology
  • The parathyroid glands produce too much Parathyroid Hormone (PTH).
Causes
  • Tumors.
  • Secondary causes include vitamin D deficiency, hypocalcemia, and chronic kidney disease (CKD).
Signs and Symptoms
  • Bones, Stones, Groans, and Psychiatric Overtones.
  • Hypercalcemia:
    • Bone pain.
    • Osteoporosis.
    • Kidney stones.
  • Groans: Nausea/Vomiting (N/V), constipation.
  • Psychiatric Overtones: Decreased neuros.
Labs/Diagnostic Tests
  • High Calcium.
  • High PTH.
Treatment
  • IV Fluids.
  • Bisphosphonates: Promotes calcium release through urine.
  • Surgery: Parathyroidectomy.

Hypoparathyroidism

Pathophysiology
  • Parathyroid glands produce too little PTH.
  • Normal Function of PTH:
    • Increase calcium by stimulating release from bones.
    • Stimulates vitamin D production.
Causes
  • Accidental damage during thyroidectomy.
  • Genetic factors.
  • Radiation to the neck.
Signs and Symptoms
  • CATS: Hypocalcemia
    • C: Convulsions (seizures).
    • A: Arrhythmias.
    • T: Tetany.
    • S: Stridor.
    • Chvostek's: Facial spasms upon tapping.
    • Trousseau's: Carpal spasm when inflating a blood pressure cuff.
Labs/Diagnostic Tests
  • Low Calcium.
  • High Phosphates.
  • Low PTH.
  • ECG Changes.
Treatment
  • Calcium supplementation.
  • Vitamin D for absorption.

Hyperthyroidism

Pathophysiology
  • Excess of T3, T4, and calcitonin: Too much thyroid hormone.
Causes
  • Autoimmune: Grave's disease.
  • Medications, iodine excess, excess levothyroxine.
Signs and Symptoms
  • General:
    • Exophthalmos (bulging eyes).
    • Goiter.
    • Weight loss.
    • Irregular menstrual cycle.
  • Cardiovascular (CV):
    • Tachycardia.
    • Palpitations.
    • Hypertension.
    • Atrial fibrillation (A-fib).
  • Metabolic:
    • Increased appetite, sweating, heat intolerance.
  • Gastrointestinal (GI):
    • Diarrhea.
  • Skin:
    • Sweating.
    • Acropachy: Fat fingers.
Labs/Diagnostic Tests
  • Thyroid panel: Increased T3/T4, decreased TSH.
  • ECG.
Treatment
  • Antithyroid Medications:
    • Methimazole.
    • Propylthiouracil (PTU).
  • Beta Blockers: Propranolol.
  • Radioactive Iodine Therapy.
  • Surgery: Thyroidectomy.

Thyroid Storm

Pathophysiology
  • Severe hypermetabolism.
Signs and Symptoms
  • High fever.
  • Tachycardia.
  • Delirium.
  • Heart Failure (HF).

Hypothyroidism

Pathophysiology
  • Deficiency in T3, T4, and calcitonin: Low thyroid hormone.
Causes
  • Autoimmune: Hashimoto's disease.
  • Thyroid destruction or removal, including thyroidectomy or radioactive iodine therapy.
Signs and Symptoms
  • General:
    • Fatigue.
    • Weakness.
    • Weight gain.
    • Cold intolerance.
  • Skin/Hair:
    • Dry/course hair.
    • Hair loss.
    • Brittle nails.
    • Myxedema.
  • Cardiovascular (CV):
    • Bradycardia.
    • Low blood pressure.
  • Neurological:
    • Depression.
  • Gastrointestinal (GI):
    • Constipation.
Labs/Diagnostic Tests
  • Low T4 and T3.
  • Primary Hypothyroidism: High TSH due to thyroid's attempt to produce more.
  • Secondary Hypothyroidism: Low TSH due to pituitary dysfunction.
Treatment
  • Hormone Replacement: Levothyroxine.

Myxedema Coma

Pathophysiology
  • Extremely low metabolism, multi-organ failure, and altered mental status.
Treatment
  • IV Levothyroxine.
  • Oxygen (O2).
  • IV Fluids.
  • Warming Methods.

Diabetes Insipidus

Pathophysiology
  • A deficiency in Antidiuretic Hormone (ADH), causing the inability to concentrate urine: Not enough ADH.
Causes
  • Nephrogenic: Kidneys fail to respond to ADH (normal ADH levels).
  • Central: Decreased ADH due to tumors, surgery, or trauma.
Signs and Symptoms
  • Genitourinary (GU):
    • Polyuria (excessive urination).
    • Dilute urine, specific gravity less than 1.005.
  • Cardiovascular (CV):
    • Tachycardia.
    • Hypotension.
  • Integumentary:
    • Dry mucous membranes.
    • Poor skin turgor.
  • General Symptoms:
    • Weight loss.
    • Weakness.
    • Polydipsia (excessive thirst).
  • Neurological:
    • Fatigue.
    • Confusion.
Labs/Diagnostic Tests
  • Urine Specific Gravity.
  • Basic Metabolic Panel (BMP): Increased sodium and serum osmolality.
  • Water Deprivation Test: Withholding fluids to assess response to desmopressin.
Treatment
  • Desmopressin: Synthetic ADH.
  • Isotonic/Hypotonic Fluids.
  • Monitoring: Intake/Output (I/O), weight, vital signs (VS), electrolytes, and neurological status.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Pathophysiology
  • Excess ADH released by the posterior pituitary gland: Too much ADH.
Causes
  • Recent head trauma.
  • Cerebrovascular diseases.
  • Tuberculosis pulmonary disease.
  • Small cell lung cancer.
Signs and Symptoms
  • Genitourinary (GU):
    • Decreased urine output.
    • Increased specific gravity.
  • Cardiovascular (CV):
    • Hypertension (HTN).
    • Weight gain.
    • Signs and symptoms of fluid overload.
  • Respiratory:
    • Pulmonary edema.
Labs/Diagnostic Tests
  • High Sodium.
  • High Specific Gravity in Urine.
  • Increased ADH.
  • CT/MRI and Chest X-ray (CXR).
Treatment
  • Fluid Restriction.
  • Hypertonic Fluids.
  • Medications: Loop diuretics.

Addison's Disease

Pathophysiology
  • Deficiency in the adrenal cortex: Low ACTH/Cortisol.
Causes
  • Primary: Autoimmune, tuberculosis (TB), metastatic cancer, adrenalectomy.
  • Secondary: Abrupt cessation of corticosteroid therapy, pituitary tumors, and hypophysectomy.
Signs and Symptoms
  • General:
    • Weakness.
    • Fatigue.
    • Weight loss.
  • Skin:
    • Hyperpigmentation (bronze coloration).
  • Cardiovascular (CV):
    • Hypotension, fainting.
  • Gastrointestinal (GI):
    • Nausea/Vomiting (N/V).
    • Abdominal pain.
    • Diarrhea.
    • Anorexia.
Labs/Diagnostic Tests
  • Low Cortisol.
  • High ACTH.
  • Low Sodium.
  • High Potassium.
  • Low Glucose.
  • ACTH Stimulation Test: In normal individuals, cortisol levels should rise with administration of ACTH.
Treatment
  • Lifelong Hormone Replacement:
    • Medications: Hydrocortisone and Fludrocortisone.

Addisonian Crisis

What is it?
  • A life-threatening condition characterized by a sudden drop in cortisol but an increase in ACTH.
Signs and Symptoms
  • Severe hypotension.
  • Shock (low blood pressure).
  • Vomiting.
  • Hypoglycemia.
Treatment
  • IV Hydrocortisone.
  • Possibly dextrose and normal saline.
  • Monitor characteristics of electrolytes and provide cardiac monitoring.

Cushing's Syndrome

Pathophysiology
  • Prolonged exposure to excess cortisol: Too much cortisol.
Causes
  • Exogenous: Long-term corticosteroid use.
  • Endogenous: Body produces too much ACTH/Cortisol due to a tumor.
Signs and Symptoms
  • Appearance:
    • Truncal obesity.
    • Buffalo hump.
    • Moon face.
  • Metabolic:
    • Increased blood sugar.
    • Spleen and lymph nodes shrink, leading to immunosuppression.
  • Musculoskeletal Symptoms:
    • Thin skin.
    • Easy bruising.
    • Poor wound healing.
    • Osteoporosis.
    • Stretch marks.
  • Cardiovascular (C/V):
    • Hypertension.
Labs/Diagnostic Tests
  • Complete Blood Count (CBC).
  • Electrolytes:
    • Hyperglycemia.
    • Hypernatremia.
  • Imaging: CT or MRI to look for lesions on adrenal glands, pituitary, lungs, GI tract, and pancreas.
Treatment
  • Hypophysectomy: If pituitary issue.
  • Adrenallectomy: If adrenal issue.
  • Tapering off corticosteroids.
  • Monitoring: Weight gain, vital signs, intake/output, infection signs, skin breakdown.
  • Dietary Considerations: Sodium restriction and increased potassium.

Conn’s Syndrome

Definition
  • Hyperaldosteronism: Excess aldosterone production.
Labs
  • Low Potassium.
  • High Sodium.
  • High Water Level.
Treatment
  • Spironolactone: Antihypertensive.
  • Surgery: If adrenal issue.
Contrast to Addison's Disease
  • Low Aldosterone: Known as Addison’s or adrenal insufficiency.
  • Treatment: Combination of insulin and D50, Kayexalate, and fludrocortisone.

Medications

Growth Hormone (Somatropin)
  • Mechanism of Action: A form of human growth hormone.
  • Indication: Growth hormone deficiency.
  • Side Effects (SE): Edema, joint pain, muscle pain, hyperglycemia, insulin resistance.
  • Considerations: Administer subcutaneously, monitor growth rate and blood glucose, assess for headaches and vision changes.
Corticosteroids
  • Mechanism of Action: Mimics cortisol, suppresses immune system, decreases inflammation, increases glucose, suppresses ACTH.
  • Indication: Adrenal insufficiency (Addison's Disease).
  • Side Effects (SE): Hyperglycemia, weight gain, osteoporosis.
  • Considerations: Do not abruptly stop medication, monitor blood sugar and signs of infection, take with food.
Vasopressin/Desmopressin (DDAVP)
  • Mechanism of Action: Mimics ADH, decreases urine output.
  • Indication: Central Diabetes Insipidus (D.I.).
  • Side Effects (SE): Hyponatremia, fluid retention.
  • Considerations: Monitor sodium, I/O, daily weight.
Levothyroxine
  • Mechanism of Action: Synthetic T4, increases metabolic rate.
  • Indication: Hypothyroidism, hormone replacement.
  • Side Effects (SE): Tachycardia, palpitations, heat intolerance.
  • Considerations: Take on an empty stomach 30-60 minutes before breakfast, lifelong therapy.
Propylthiouracil (PTU)
  • Mechanism of Action: Blocks thyroid hormone production, inhibiting the conversion of T4 to T3.
  • Indication: Hyperthyroidism, thyroid storm.
  • Side Effects (SE): Agranulocytosis, hepatotoxicity, hypothyroidism.
  • Considerations: Monitor WBC, report sore throat, and fever.
Radioactive Iodine (RAI)
  • Mechanism of Action: Destroys thyroid tissue.
  • Indication: Hyperthyroidism, Graves' disease.
  • Side Effects (SE): Hypothyroidism, dry mouth, radiation precautions.
  • Considerations: Avoid pregnancy and adhere to radiation safety precautions.
Methimazole
  • Mechanism of Action: Blocks thyroid hormone production.
  • Indication: Graves' disease.
  • Side Effects (SE): Agranulocytosis, hypothyroidism.
  • Considerations: Monitor WBC levels.