Chronic Obstructive Pulmonary Disease

Progressive, largely irreversible airflow limitation from chronic airway/alveolar inflammation, predominantly smoking-related (also biomass fuel exposure, occupational dusts, alpha-1 antitrypsin deficiency). Encompasses chronic bronchitis (clinical (productive cough ≥3 months × 2 years) and emphysema (pathological) alveolar destruction), usually overlapping.

Classified: GOLD spirometric grades 1-4 (post-bronchodilator FEV1 % predicted): mild (≥80%), moderate (50-79%), severe (30-49%), very severe (<30%). GOLD ABE groups (symptom burden via mMRC/CAT + exacerbation history) guide treatment.

Progressive exertional dyspnea, chronic productive cough, wheeze, reduced exercise tolerance. Examination: hyperinflated chest, reduced breath sounds, prolonged expiration, accessory muscle use/pursed-lip breathing in advanced disease, cor pulmonale signs (raised JVP, peripheral edema) in advanced disease. Exacerbations: acute symptom worsening beyond normal variation, usually infection-triggered.

• Spirometry (essential): post-bronchodilator FEV1/FVC <0.7 confirms diagnosis
• CXR: hyperinflation, flattened diaphragms, bullae, mainly excludes other pathology
• Alpha-1 antitrypsin: consider if age <45 or non-smoker or strong family history
• FBC: polycythemia (chronic hypoxia) or anemia
• ABG: advanced disease/exacerbation assessment
• CT chest: characterizes emphysema, assesses for bronchiectasis/malignancy
• Echocardiogram: if cor pulmonale/pulmonary hypertension suspected

Differentials: asthma (younger, more reversible, atopic, overlap syndrome exists), bronchiectasis, heart failure, lung cancer, interstitial lung disease.

Stable disease:

• Smoking cessation: single most important intervention
• Vaccination: influenza annually, pneumococcal, COVID-19
• Pulmonary rehabilitation: structured exercise/education
• Inhaled therapy by GOLD group: Group A, SABA/SAMA prn or single long-acting bronchodilator; Group B, LABA+LAMA combination; Group E (high exacerbation risk), LABA+LAMA, add ICS (triple therapy) if eosinophils ≥300 or asthma overlap
• Roflumilast: add-on for severe chronic bronchitis phenotype with frequent exacerbations despite triple therapy
• LTOT: for PaO2 ≤7.3kPa (or ≤8kPa with cor pulmonale/polycythemia), survival benefit, minimum 15h/day
• Mucolytics (carbocisteine): may reduce exacerbations with chronic productive cough

Acute exacerbation:

• Increased short-acting bronchodilators (salbutamol + ipratropium)
• Oral corticosteroids: prednisolone 30-40mg od × 5 days
• Antibiotics if increased sputum purulence: amoxicillin, doxycycline, or clarithromycin, 5-7 days
• Controlled oxygen: target SpO2 88-92% (avoid CO2 retention)
• NIV (BiPAP): for persistent hypercapnic respiratory acidosis despite medical therapy, reduces intubation need, mortality benefit
• ICU/intubation if NIV failing/contraindicated, severe acidosis, reduced consciousness

Referral: pulmonology for diagnostic uncertainty, young-onset disease, frequent exacerbations despite optimized therapy, or surgical/transplant consideration.