Lecture on Chronic Obstructive Pulmonary Disease (COPD)

Introduction to COPD

• Definition: Chronic obstructive pulmonary disease (COPD) is a common respiratory condition characterized by airflow limitation.
• Exacerbations and Comorbidities: These contribute to the overall severity in individual patients.

Signs and Symptoms

• Cardinal Symptoms:
  • Dyspnea (difficulty breathing)
  • Chronic cough
  • Sputum production
• Less Common Symptoms: Wheezing and chest tightness

Risk Factors

• Major Risk Factor: Smoking (95% of cases)
• Others:
  • Air pollution
  • Low birth weight
  • Recurrent lung infections
  • Cannabis smoking
  • Low socio-economic status
  • Alpha-1 antitrypsin deficiency

COPD Subtypes

• Chronic Asthma
• Chronic Bronchitis (Blue Bloaters)
• Emphysema (Pink Puffers)

Chronic Bronchitis (Blue Bloaters)

• Clinical Characteristics:
  • Cyanosis (blue appearance)
  • Severe dyspnea
  • Lack of exercise
• Pathophysiology:
  • Inflammatory change leading to mucociliary dysfunction
  • Increased goblet cell secretion and numbers
  • Excessive mucus production
  • Airway obstruction from bronchoconstriction and mucus
• Consequences:
  • VQ mismatch (ventilation-perfusion mismatch)
  • Hypoxemia (low blood oxygen)
  • Hypercapnia (high CO2 in blood)
  • Polycythemia (increased red blood cells)
  • Respiratory acidosis
  • Potential for right-sided heart failure (cor pulmonale)

Emphysema (Pink Puffers)

• Clinical Characteristics:
  • Muscle wasting
  • Barrel chest
  • Air trapping
• Pathophysiology:
  • Loss of elastic fibers and alveolar walls
  • Decreased alveolar recoil
  • Air trapping leading to increased end-expiratory volume
  • Decrease in perfusion and ventilation
  • Matched VQ deficit
• Consequences:
  • Dyspnea
  • Cachexia

Alpha-1 Antitrypsin Deficiency

• Description: Hereditary condition leading to an imbalance of proteases and anti-proteases, resulting in lung damage.

Summary

• Blue Bloaters: Chronic bronchitis, characterized by cyanosis and productive cough.
• Pink Puffers: Emphysema, characterized by barrel chest and muscle wasting.

Investigations (Next Topic)

• Types of investigations for patients with difficulty breathing, sputum production, and cough will be discussed next.