Endocrine System Overview & Hyperthyroidism

Key Endocrine Glands

• Adrenal Gland: Focus on it, highly tested in exams.
• Thyroid Gland: Critical knowledge area. Do not need to study thymus, pineal, parathyroids for this lecture.

Thyroid Gland Disorders

Hyperthyroidism

• Associated with Hypermetabolism: Turn hyperthyroidism into hypermetabolism.
• Logical Signs and Symptoms: Inferred from high metabolic rate.
  • Weight loss: Skinny appearance
  • High pulse rate
  • High blood pressure
  • Irritability and hyperactivity
  • Heat intolerance (overheats easily)
  • Cold tolerance (like a furnace)
  • Exophthalmos (bulging eyes)

Grave’s Disease

• Disease Name: Associated with hyperthyroidism.
  • Memory Tip: Running yourself into the grave = Hyperthyroidism.

Treatment Options for Hyperthyroidism

1. Radioactive Iodine: Patient isolation for 24 hours; careful handling of urine.
2. PTU (Propylthiouracil): Lowers thyroid activity; monitor white blood cell count due to immune suppression.
3. Thyroidectomy: Removal of part or all of the thyroid.

• Must differentiate between total and subtotal thyroidectomy.

Thyroidectomy Considerations

• Total Thyroidectomy: Requires lifelong hormone replacement; risk of hypocalcemia due to potential parathyroid removal.
  • Signs of Hypocalcemia: Irritability, muscle spasms, seizures
• Subtotal Thyroidectomy: Risk for thyroid storm (thyrotoxicosis).
  • Thyroid Storm Symptoms: High fever, severe tachycardia, delirium.
  • Treatment: Cooling methods, oxygen, potentially wait it out as it’s self-limiting.

Post-operative Risks

1. First 12 Hours: Focus on airway and hemorrhage for both total and subtotal.
2. 12-48 Hours: Differentiate between types:

• Total Thyroidectomy: Risk of tetany (hypocalcemia).
  • Subtotal Thyroidectomy: Risk of thyroid storm.

3. After 48 Hours: Watch for infection.

• Hypothyroidism Overview
  • Associated with Hypometabolism: Turn hypothyroidism into hypometabolism.

Hypothyroidism

• Logical Signs and Symptoms: Inferred from low metabolic rate.
  • Weight gain: Obese appearance
  • Low pulse rate
  • Low blood pressure
  • Lethargic personality
  • Cold intolerance (always cold)
  • Heat tolerance

Myxedema

• Disease Name: Associated with hypothyroidism.
• Treatment: Thyroid hormone replacement (Synthroid, Levothyroxine).
• Special Note: Do not sedate hypothyroid patients - risk of myxedemic coma.
  • Pre-op order precautions: Do not hold thyroid pills without express orders/supervision.

Adrenal Gland Disorders

Addison’s Disease

• Under-secretion of Adrenal Cortex: Results in hyperpigmentation and inability to handle stress.
• Treatment: Steroid replacement ending in -sone (e.g., Prednisone).

Cushing’s Syndrome

• Over-secretion of Adrenal Cortex: Memory link - more symptoms in Cushing's
• Symptoms:
  • Moon face (round face)
  • Central obesity with thin extremities
  • Buffalo hump (fat deposit between shoulders)
  • Hirsutism (excess hair)
• Treatment: Treat underlying cause; monitor for high blood pressure, regulate glucose.