Hypothyroidism: NCLEX Review

Overview

• Presenter: Sarah from RegisteredNurseAriene.com
• Focus: NCLEX review on hypothyroidism
• Next Video: Hyperthyroidism
• Quiz: Available on registernurserian.com

Definition

• Hypothyroidism: An underactive thyroid gland producing insufficient T3 and T4 hormones.

Diagnosis

• Blood test measuring T3, T4, and TSH levels.

Anatomy and Function

• Thyroid Gland:

  • Location: Below the larynx, shaped like a butterfly.
  • Associated with the parathyroid glands regulating calcium levels.
  • Produces hormones: T3, T4, and calcitonin; T3 and T4 are crucial for metabolism.

• Role of Iodine:

  • Essential for hormone production.
  • Obtained from food; deficiency can cause hypothyroidism.

Functions of T3 and T4

• Burning Calories: Insufficient levels result in weight gain.
• Cell Replacement: Delayed cell turnover.
• Digestion: Slow digestion leading to constipation.
• Sympathetic Nervous System: Reduced alertness and reflexes.
• Body Temperature: Poor regulation leading to cold intolerance.
• Heart Rate and Brain Development: Critical for developing children.

Thyroid Stimulating Hormone (TSH) and Feedback Loop

• TSH Production:
  • Originates from the anterior pituitary gland.
  • Stimulates thyroid to release T3 and T4.
• Feedback Loop:
  • Hypothalamus releases TRH → Anterior pituitary releases TSH → Thyroid releases T3 and T4.
  • Disruptions in this loop can lead to hypothyroidism.

Signs and Symptoms

• General: Slow and low body function.
• Common Symptoms:
  • Weight gain
  • Cold intolerance
  • Goiter due to thyroid stimulation
  • Fatigue and drowsiness
  • Slow heart rate
  • Thinning, brittle hair
  • Depression, memory loss
  • Constipation
  • Myxedema (puffy face)
  • Menstrual irregularities

Causes

• Hashimoto's Thyroiditis: Most common cause; autoimmune disorder attacking the thyroid.
• Iodine Deficiency: Affects hormone production.
• Pituitary Tumor: Inhibits TSH secretion.
• Treatment for Hyperthyroidism: Antithyroid medications can lead to hypothyroidism.

Nursing Interventions

• Monitor for Myxedema Coma:
  • Life-threatening; caused by severe hypothyroidism.
  • Symptoms: Hypothermia, extreme drowsiness, respiratory failure.
• General Monitoring: Heart rate, blood pressure, respiratory rate, blood glucose, weight.
• Medication Sensitivity:
  • Avoid narcotics; use non-narcotic pain management like Tylenol.

Pharmacological Management

• Thyroid Replacement Therapy:

  • Common medications: Synthroid (Levothyroxine), Cytomel (Liothyronine), Thyrolar (Liotrix).

• Patient Education:

  • Never stop medications abruptly.
  • Takes time to see symptom improvement.
  • Best taken in the morning on an empty stomach.
  • Recognize signs of toxicity (hyperthyroidism symptoms).
  • Avoid taking with GI meds within 4 hours.

Conclusion

• Hypothyroidism requires careful monitoring and patient education.
• Further resources available on registernurserian.com and YouTube channel for additional endocrine system conditions.

Please visit the website for a quiz and check the next video on hyperthyroidism.