Pathophysiology
Progressive airflow limitation not fully reversible. Emphysema: alveolar wall destruction. Chronic bronchitis: productive cough >3 months for 2 consecutive years. Smoking is primary cause (80-90%).
Pharmacotherapy
Bronchodilators cornerstone: SABA/SAMA for rescue, LABA/LAMA for maintenance. ICS for frequent exacerbators. Oxygen for hypoxemia (SpO2 <88%) — improves survival. Pulmonary rehab. Smoking cessation.
Acute Exacerbation
Caused by infection or triggers. Treatment: oxygen (target SpO2 88-92%), bronchodilators, corticosteroids (prednisone 40mg x5 days), antibiotics if bacterial. Consider BiPAP for respiratory acidosis.
Important Notes
- Low-flow oxygen in COPD — excessive oxygen can suppress hypoxic drive and worsen hypercapnia.
- Target SpO2 88-92% for COPD patients — not 95-100%.
Clinical Tips
- Pursed-lip breathing keeps airways open longer, reducing air trapping and dyspnea.
- Vaccination (pneumococcal, influenza, COVID) reduces COPD exacerbations significantly.
Summary
COPD management focuses on smoking cessation, bronchodilators, oxygen therapy (target 88-92%), and prompt treatment of exacerbations.
