Lung disease characterized by airway obstruction due to inflammation of the small airways; caused predominantly by inhaled toxins, especially via smoking
Aetiology
- SMOKING (90-98%) - most common in ex-smokers >35
- Age (>40)
- Biomass fuel exposure
- Occupational dusts/chemicals
- Air pollution
- Genetic predisposition - α1-antitrypsin deficiency (early-onset COPD)
- Results in failure to break down neutrophil elastase
- More likely to develop COPD at a younger age, especially if they smoke
Pathophysiology
Chronic bronchitis
- Cigarette smoke → chronic neutrophilic inflammation → scarring and fibrosis
- Hypertrophy of mucus secreting glands and hyperplasia of goblet cells
Emphysema
- Inflammation → neutrophils release proteases → break down elastin walls of alveoli → loss of elastic recoil (abnormally increased compliance)
Clinical presentation
Respiratory Symptoms
Feature | Description | Clinical Clue |
Dyspnea | Progressive, persistent, worse on exertion | Earliest and most disabling symptom |
Chronic cough | Daily or intermittent | Often precedes dyspnea |
Sputum production | Mucoid or purulent | Suggests chronic bronchitis phenotype |
Wheeze | Variable | More prominent during exacerbations |
Chest tightness | Non-specific | Exertional |
Exacerbation Symptoms
- Acute worsening of
- Dyspnea
- Sputum volume
- Sputum purulence
- Often triggered by infection or pollution
Physical Examination Findings
Early Disease
- Often normal
- Prolonged expiratory phase
Advanced Disease
Sign | Pathophysiology |
Barrel chest | Hyperinflation |
Use of accessory muscles | Increased work of breathing |
Pursed-lip breathing | Auto-PEEP reduction |
Decreased breath sounds | Air trapping |
Hyperresonance | Emphysema |
Cyanosis | Chronic hypoxemia |
Peripheral edema, raised JVP | Cor pulmonale |
Systemic Manifestations
- Weight loss, muscle wasting
- Osteoporosis
- Depression/anxiety
- Cardiovascular disease
Investigations
Spirometry (Diagnostic Cornerstone)
Required Criterion
- Post-bronchodilator FEV₁/FVC < 0.70
✔ Confirms persistent airflow limitation
Spirometric Patterns
⚠️ Partial reversibility does not exclude COPD
Parameter | Finding |
FEV₁ | Reduced |
FVC | Normal or reduced |
FEV₁/FVC | < 0.70 |
Bronchodilator reversibility | Incomplete |
Severity of Airflow Limitation (GOLD Grades)
Grade | FEV₁ (% predicted) |
GOLD 1 (Mild) | ≥80% |
GOLD 2 (Moderate) | 50–79% |
GOLD 3 (Severe) | 30–49% |
GOLD 4 (Very Severe) | <30% |
Exacerbation Risk Assessment
Group | Symptoms | Exacerbations |
A | Low (mMRC 0–1 or CAT <10) | 0–1 (no hospitalization) |
B | High (mMRC ≥2 or CAT ≥10) | 0–1 |
E | Any | ≥2 OR ≥1 hospitalization |
Management
Initial Treatment
Group | Recommended Therapy |
A | Single bronchodilator (LABA or LAMA) |
B | LABA + LAMA |
E | LABA + LAMA ± ICS* |
Stable COPD (Stepwise)
- Group A: LABA or LAMA → AlternativeSABA ± SAMA
- Group B: LABA + LAMA
- Group C: LABA + LAMA ± ICS
- Very severe: Triple therapy ± roflumilast
Acute Exacerbation
- Oxygen (target SpO₂ 88–92%)
- SABA ± SAMA
- Short-Acting β₂-Agonist (SABA)
- Salbutamol
- 2.5–5 mg nebulized every 20 min × 3
- 4–10 puffs via spacer every 20 min
- Short-Acting Muscarinic Antagonist (SAMA)
- Ipratropium bromide
- 0.5 mg nebulized every 20 min × 3
- Systemic corticosteroids
- Prednisolone 40 mg PO daily × 5 days
- Methylprednisolone 3 × 32 mg IV
- Antibiotics (if purulent sputum)
- Mild-Moderate
- Amoxicillin 500 mg PO 3x1 for 5-7 days
- Amoxicillin–clavulanate 625 mg PO 3x1 for 5-7 days
- Azithromycin 500 mg PO 1x1 for 3-5 days
- Clarithromycin 500 mg PO 2x1 for 5-7 days
- Doxycyclin 100 mg PO 2x1 for 5-7 days
- Severe
- Ceftriaxone 1-2 g/24 hr IV
- Ampicillin–sulbactam 1.5-3 g/6-8 hr IV
- Levofloxacin 750 mg PO 1x1
- NIV if hypercapnic respiratory failure
💊 Drugs Used in COPD (with Dosage)
Drug Class | Examples | Mechanism | Route | Typical Dose |
Short-Acting β2-Agonists (SABA) | Salbutamol (Albuterol) | β2 stimulation → bronchodilation | Inhaled (MDI/nebulizer) | MDI: 100–200 mcg every 4–6 hr PRN; Neb: 2.5 mg every 4–6 hr |
Long-Acting β2-Agonists (LABA) | Salmeterol | Prolonged β2 agonist | Inhaled | 50 mcg twice daily |
ㅤ | Formoterol | Same (faster onset) | Inhaled | 12 mcg twice daily |
Short-Acting Muscarinic Antagonists (SAMA) | Ipratropium | Blocks M3 receptor → bronchodilation | Inhaled | 2 puffs (40 mcg) every 6 hr or neb 0.5 mg |
Long-Acting Muscarinic Antagonists (LAMA) | Tiotropium | Long-acting M3 blockade | Inhaled | 18 mcg once daily |
ㅤ | Glycopyrronium | Same | Inhaled | 50 mcg once daily |
Inhaled Corticosteroids (ICS) | Budesonide | Anti-inflammatory | Inhaled | 200–400 mcg twice daily |
ㅤ | Fluticasone | Same | Inhaled | 100–250 mcg twice daily |
Combination Inhalers | LABA + ICS (e.g., Formoterol + Budesonide) | Bronchodilation + anti-inflammatory | Inhaled | Example: 160/4.5 mcg, 1–2 puffs BID |
ㅤ | LABA + LAMA | Dual bronchodilation | Inhaled | Varies (e.g., indacaterol/glycopyrronium once daily) |
ㅤ | LABA + LAMA + ICS | Triple therapy | Inhaled | Varies |
Methylxanthines | Theophylline | PDE inhibition → bronchodilation | Oral | 200–400 mg/day (titrate; target level 5–15 mcg/mL) |
Phosphodiesterase-4 Inhibitor | Roflumilast | ↓ inflammation (PDE-4 inhibition) | Oral | 500 mcg once daily |
Systemic Corticosteroids (Exacerbation) | Prednisolone | Anti-inflammatory | Oral | 40 mg daily × 5 days |
Antibiotics (if indicated) | Amoxicillin-clavulanate, Azithromycin | Treat infection | Oral/IV | Varies (e.g., Amox-clav 625 mg TID) |
Mucolytics | N-acetylcysteine | Breaks mucus | Oral | 600 mg once or twice daily |
Oxygen Therapy | Oxygen | Correct hypoxemia | Inhaled | Target SpO₂ 88–92% |
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