COPD
GOLD 2025: chronic airflow limitation that is not fully reversible
Two patterns
Emphysema
- Alveolar walls destroyed; air trapping
- Barrel chest, thin, pursed-lip breathing
- Hyperresonance; diminished breath sounds
Chronic bronchitis
- Productive cough ≥3 months for 2 years in a row
- Frequent infections, hypoxemia, edema
- Rhonchi, wheezes; possible cor pulmonale
Diagnosis: spirometry after bronchodilator: FEV₁/FVC <0.70. Main cause: smoking (also biomass smoke from cooking fuels, occupational dusts, alpha-1 antitrypsin deficiency).
Oxygen in COPD Updated
Target SpO₂ 88–92% in people at risk of CO₂ retention.
Why: too much oxygen worsens ventilation–perfusion mismatch and reduces hemoglobin's CO₂ carrying (Haldane effect), so CO₂ rises. The old "hypoxic drive" explanation is outdated.
Never withhold oxygen from a hypoxic patient. Titrate to the target and watch for drowsiness (rising CO₂).
Long-term home O₂ if resting PaO₂ ≤55 mmHg or SpO₂ ≤88%.
Medications
| Drug group | Examples | Role |
|---|---|---|
| LAMA + LABA | tiotropium, umeclidinium + salmeterol, formoterol, vilanterol | Mainstay maintenance for most patients |
| Inhaled corticosteroid (added) | fluticasone, budesonide | Only with long-acting bronchodilators, if exacerbations and blood eosinophils ≥300 (or ≥100 with frequent exacerbations). ↑ pneumonia risk. |
| SABA / SAMA | albuterol; ipratropium | Rescue for symptoms |
| Add-ons | Exacerbations: roflumilast; azithromycin (selected); dupilumab (eosinophils ≥300) or mepolizumab (≥150) despite triple therapy. Persistent symptoms: ensifentrine (nebulized) | Newer options New |
Acute exacerbation
- SABA ± ipratropium (nebulizer or MDI with spacer).
- Systemic corticosteroid (e.g., prednisone 40 mg daily for 5 days).
- Antibiotics if sputum becomes purulent or ventilation is needed.
- Controlled oxygen 88–92%; ABG.
- BiPAP for hypercapnic respiratory acidosis (pH ≤7.35, PaCO₂ >45).
Nursing and teaching
- Smoking cessation: the single most effective intervention.
- Pursed-lip breathing (in through nose, out slowly through pursed lips, exhale twice as long); huff coughing.
- Upright or tripod position; pace activities; pulmonary rehab.
- High-calorie, high-protein small frequent meals; rest before eating.
- Fluids ~2–3 L/day to thin secretions unless restricted (e.g., HF).
- Vaccines: influenza yearly, COVID-19, pneumococcal, RSV, Tdap, zoster.
Priority
A COPD patient who becomes drowsy or confused on oxygen may be retaining CO₂: check the ABG, titrate oxygen down to the target range, and prepare for BiPAP. Cor pulmonale (right heart failure from lung disease): JVD, edema, hepatomegaly.