Overview
This lecture covers the basics of Chronic Obstructive Pulmonary Disease (COPD), including its definition, causes, pathophysiology, types, symptoms, complications, and diagnostic methods.
Definition & Key Points
- COPD is a chronic, irreversible lung disease causing airflow obstruction and breathing difficulties.
- Bronchioles become inflamed, narrowed, and produce excess mucus, reducing oxygen intake and limiting carbon dioxide exhalation.
- Loss of alveolar sac elasticity prevents full exhalation, resulting in air trapping and poor gas exchange.
- COPD is usually progressive and varies in severity among patients.
- It is managed, not cured, with lifestyle changes and medications.
Causes & Risk Factors
- Main cause: long-term exposure to lung irritants, especially cigarette smoking.
- Other causes include air pollution and occupational exposure to dust or chemicals.
- COPD develops gradually, often detected in middle age.
Types of COPD
- Chronic Bronchitis ("Blue Bloaters"): Marked by cyanosis (bluish skin/lips) and edema due to hypoxemia and right-sided heart failure.
- Emphysema ("Pink Puffers"): Characterized by hyperventilation (puffing), a pink complexion, and barrel chest due to alveolar damage and air trapping.
Pathophysiology
- In chronic bronchitis, inflamed bronchioles and mucus block airflow, causing hyperinflated lungs and a flattened diaphragm.
- In emphysema, alveolar sacs lose elasticity, trapping air and reducing gas exchange, leading to increased use of accessory respiratory muscles.
- Both types result in respiratory acidosis (high CO₂, low O₂ levels).
Signs & Symptoms (Mnemonic: LUNG DAMAGE)
- Lack of energy and activity intolerance due to limited oxygen.
- Unintentional weight loss and poor nutrition (especially in emphysema).
- Abnormal blood gases: high CO₂ (>45), low O₂ (<90), and respiratory acidosis.
- Chronic cough (dry or productive, especially in bronchitis).
- Accessory muscle use and abnormal lung sounds (diminished, crackles, wheezes).
- Skin color changes: cyanosis (blue) or pink complexion.
- Increased anterior-posterior chest diameter (barrel chest) in emphysema.
- Tripod breathing position and severe shortness of breath.
Complications
- Right-sided heart failure (cor pulmonale) and pulmonary hypertension.
- Spontaneous pneumothorax (lung collapse).
- Frequent lung infections (e.g., pneumonia) and increased lung cancer risk.
Diagnosis
- Spirometry measures lung function: forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁).
- Low values indicate restrictive or obstructive airflow and severity of disease.
Key Terms & Definitions
- COPD — Chronic Obstructive Pulmonary Disease, a progressive, irreversible lung disorder with airflow limitation.
- Alveolar Sac — Air sacs in the lungs where gas exchange occurs.
- Bronchiole — Small airways in the lungs affected by inflammation and narrowing in COPD.
- Cyanosis — Bluish discoloration of the skin due to low oxygen.
- Barrel Chest — Increased chest diameter due to lung hyperinflation.
- Spirometry — Lung function test measuring inhalation and exhalation volumes.
Action Items / Next Steps
- Watch part two for medications and nursing interventions.
- Complete the accompanying NCLEX review quiz.