Orientation notes for study, based on GOLD and NICE. Check the Kenya MoH and your hospital guideline before prescribing.
Definition
COPD is a common, preventable and treatable disease characterised by persistent respiratory symptoms and airflow limitation that is not fully reversible, caused by abnormalities of the airways (chronic bronchitis, small airways disease) and/or alveoli (emphysema) from significant exposure to noxious particles or gases.
Causes and risk factors
- Cigarette smoking (commonest cause worldwide).
- Biomass fuel smoke (cooking with wood or charcoal in poorly ventilated kitchens): a leading cause in Kenya, especially in women who never smoked.
- Occupational dusts and fumes (mining, farming, cement, textile).
- Alpha-1 antitrypsin deficiency (young, lower-zone emphysema, family history, liver disease).
- Post-TB lung damage, recurrent childhood infections, HIV, poor lung growth.
- Ageing, air pollution.
Pathophysiology
- Chronic bronchitis: goblet cell and mucous gland hypertrophy, airway inflammation (neutrophils, macrophages, CD8 T cells), luminal narrowing.
- Emphysema: destruction of alveolar walls by protease–antiprotease imbalance, with loss of elastic recoil, air trapping and hyperinflation. Centriacinar (smoking, upper zones), panacinar (alpha-1 antitrypsin, lower zones).
- Result: airflow obstruction, V/Q mismatch (hypoxaemia), hypercapnia in advanced disease, pulmonary hypertension and cor pulmonale.
Clinical features
- Symptoms: chronic cough, sputum, progressive exertional breathlessness (grade with the MRC dyspnoea scale), wheeze, recurrent chest infections, weight loss and fatigue in severe disease.
- Signs: barrel chest, hyperinflation, reduced cricosternal distance, pursed-lip breathing, accessory muscle use, hyper-resonant percussion, reduced cardiac dullness and liver displaced down, prolonged expiration, wheeze, quiet breath sounds, cyanosis, flapping tremor and bounding pulse (CO2 retention), signs of cor pulmonale (raised JVP, ankle oedema, loud P2).
- "Pink puffer" (emphysema: breathless, thin, no cyanosis) versus "blue bloater" (chronic bronchitis: cyanosed, oedematous): a descriptive pair, with most patients having a mixture.
Investigations
- Spirometry (diagnostic): post-bronchodilator FEV1/FVC below 0.7 with symptoms and exposure.
- GOLD grade (by FEV1 % predicted): 1 mild (80% or more), 2 moderate (50–79%), 3 severe (30–49%), 4 very severe (below 30%).
- Chest X-ray: hyperinflation, flattened diaphragms, bullae, enlarged hila; excludes lung cancer, pneumothorax, heart failure.
- Full lung function: raised TLC and RV, reduced DLCO in emphysema.
- ABG/oximetry, FBC (polycythaemia), ECG/echo (cor pulmonale), alpha-1 antitrypsin level in young or non-smoker patients, sputum culture, HIV test and TB screen.
Management of stable COPD
- Stop smoking (counselling and pharmacotherapy: the only measure that reduces decline); reduce biomass exposure.
- Vaccinations: influenza yearly, pneumococcal, COVID-19.
- Pulmonary rehabilitation and exercise; nutrition.
- Inhaled therapy (GOLD):
- Group A (few symptoms): a bronchodilator (short- or long-acting).
- Group B (more symptoms): LABA plus LAMA.
- Group E (exacerbations): LABA plus LAMA; add ICS if blood eosinophils 300 or more/µL (or 100 or more with frequent exacerbations).
- SABA or SAMA as needed for relief.
- Check inhaler technique and adherence.
- Other drugs in selected patients: roflumilast, azithromycin (if frequent exacerbations in former smokers), mucolytics.
- Long-term oxygen therapy (LTOT): for PaO2 below 7.3 kPa (55 mmHg), or 7.3–8 kPa with cor pulmonale, polycythaemia or pulmonary hypertension, used at least 15 hours a day; patient must not smoke.
- Surgery: bullectomy, lung volume reduction, lung transplant in selected cases.
- Palliative care for end-stage disease.
Acute exacerbation of COPD
- Definition: acute worsening of breathlessness, cough or sputum (volume or purulence), commonly infective (viral or bacterial).
- Management:
- Controlled oxygen: target SpO2 88–92%, using a Venturi mask (24–28%). Too much oxygen worsens hypercapnia.
- Nebulised bronchodilators (salbutamol and ipratropium), driven by air (not oxygen) if CO2 retention.
- Oral prednisolone 30–40 mg daily for 5 days.
- Antibiotics if sputum is purulent or pneumonia (amoxicillin, doxycycline or co-amoxiclav).
- Non-invasive ventilation (NIV) if respiratory acidosis persists (pH below 7.35 with PaCO2 above 6.5 kPa) despite treatment; intubation if NIV fails.
- Check ABG early and repeat; treat heart failure, PE, pneumothorax if present.
- Decide escalation and ceiling of care with the patient.
Complications
- Respiratory failure (type 2), cor pulmonale, polycythaemia, pneumothorax (bullae), recurrent infections, lung cancer, osteoporosis, depression, malnutrition and cachexia.
Prognosis
- Worsened by continued smoking, low FEV1, frequent exacerbations, low BMI, hypoxaemia, cor pulmonale. BODE index (BMI, obstruction, dyspnoea, exercise capacity) predicts survival.
Exam points
- FEV1/FVC below 0.7 post-bronchodilator diagnoses COPD.
- Smoking cessation and LTOT (more than 15 hours a day) are the only interventions that improve survival.
- Oxygen target 88–92% in an exacerbation.
- Kenya: biomass smoke and post-TB lung disease are important causes.
Pharmacology at a glance
Tap a drug name for its full card (how it works, adverse effects, cautions, dose), then use Back to this note to return to this spot. Condition guide: COPD drugs.
| Drug | Class | Role here | Watch for |
|---|---|---|---|
| Salbutamol | Short-acting β₂-agonist | Relief of breathlessness; nebulised in exacerbations | Tremor, palpitations, low potassium |
| Ipratropium | Short-acting antimuscarinic | Nebulised with salbutamol in exacerbations | Dry mouth, urinary retention |
| Tiotropium | Long-acting antimuscarinic (LAMA) | Maintenance bronchodilator | Dry mouth, urinary retention in older men |
| Budesonide–formoterol | Inhaled steroid plus long-acting β₂-agonist | Add the steroid if frequent exacerbations and eosinophils 300/µL or more | Pneumonia risk with inhaled steroids, thrush |
| Prednisolone | Systemic corticosteroid | Exacerbation: 30–40 mg for 5 days | High glucose, mood change |
| Doxycycline | Tetracycline | Exacerbation with purulent sputum | Photosensitivity, oesophagitis (take upright with water) |
| Amoxicillin | Penicillin | Alternative for a purulent exacerbation | Rash, diarrhoea, allergy |
| Co-amoxiclav | Penicillin plus β-lactamase inhibitor | Resistant organisms or pneumonia | Diarrhoea, liver injury |
| Azithromycin | Macrolide | Prevents exacerbations in former smokers with frequent attacks | QT prolongation, hearing loss |
| Roflumilast | Phosphodiesterase-4 inhibitor | Severe COPD with chronic bronchitis and exacerbations | Weight loss, diarrhoea, low mood |
Oxygen is a drug too: aim for 88–92% in an exacerbation; too much oxygen can worsen carbon dioxide retention.
Practice questions
1. A 62-year-old smoker has breathlessness. Post-bronchodilator FEV1/FVC 0.55 and FEV1 40% predicted. The GOLD grade is: A. 1 · B. 2 · C. 3 · D. 4 · E. Cannot be graded Answer: C (30–49%).
2. A patient with COPD exacerbation has pH 7.28 and PaCO2 8 kPa on controlled oxygen with nebulisers and steroids. Next step: A. Increase oxygen · B. Non-invasive ventilation · C. Discharge · D. Stop steroids · E. Sedation Answer: B.
3. The oxygen saturation target in a COPD exacerbation is: A. 100% · B. 94–98% · C. 88–92% · D. 80–85% · E. Above 98% Answer: C.