Chronic Obstructive Pulmonary Disease (COPD) is progressive, irreversible airway obstruction usually due to smoking.
Emphysema: enlargement of air spaces and destruction of parenchyma causing closure of small airways and loss of lung elasticity.
Lung Dysfunction results from airflow limitation (loss of elastic recoil, increased collapsibility/ narrowing of small airways) and impaired gas exchange (V/Q mismatch, alveolar destruction, increased dead space causing hypercarbia)
- Cigarette smoking (> 90% of cases), air pollution, occupational inhalation, alpha 1 – AT deficiency)
- Genetic predisposition.
Signs and Symptoms:
Patients usually have a combination of bronchitis and emphysematous signs and symptoms
Chronic Bronchitis (Blue Bloaters):
- A productive cough for at least 3 months during 2 or more successive years.
- Exertional Dyspnoea
- Right Heart Failure
- Rhonchi/ Wheezes
- Cyanosis/ hypoxemia
- Late CO2 retention
Emphysematous Symptoms (Pink Puffers):
- A minimal cough
- Weight loss
- Severe dyspnoea
- Increased work of breathing
- Prolonged expiration
- Flattened diaphragm
- Pursed lip breathing
- Accessory muscle use
- Minimal hypoxemia
- Decreased air movement
- Barrel chest tripod sitting
- Normal pCO2
- Pulmonary Function Tests (PFTs):
- Decreased FEV1,/ forced Ventricle Capacity (FVC) (<70% predicted)
- Increased Lung Volumes (FRC, RV, RV/ TLC ratio): due to airway obstruction, resulting in airway trapping and hyperinflation.
- Decreased diffusing capacity: especially in emphysema
- X-Ray Chest:
- Flattened diaphragms, hyperinflation, bullae and increased lucency in lung; small heart
- Arterial Blood Gas (ABG):
- Hypoxaemia (due to V/Q mismatch), hypercarbia
- Complete Blood Count (CBC):
- Polycythemia secondary to chronic hypoxemia
- CT Scan:
- Centrilobular emphysema, bullae
- Stop smoking
- Bronchodilators: anticholinergics are the preferred agents; long-acting Beta-agonists decrease infections and improve symptoms.
- Oxygen therapy: continuous/ night time O2
- Non-invasive positive pressure ventilation (BiPAP)
Lung volume reduction surgery and lung transplant may benefit selected patients with end-stage disease