COPD: Diagnosis, Inhalers, Oxygen and Exacerbations

Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable lung disease with persistent respiratory symptoms and airflow limitation that is not fully reversible. It includes chronic bronchitis and emphysema. COPD is one of the leading causes of death worldwide.

Causes and risk factors

Tobacco smoking — the main cause.
Biomass fuel smoke from cooking and heating with wood, dung or crop waste in poorly ventilated homes — an important cause, especially in women in low- and middle-income countries.
Occupational dusts and chemicals, and air pollution.
Alpha-1 antitrypsin deficiency — consider in young patients or non-smokers with emphysema.
Poor lung growth in childhood and recurrent childhood infections.

Clinical features

Chronic, progressive breathlessness on exertion, chronic cough and sputum production, wheeze and recurrent chest infections, usually in a person over 35–40 with a history of exposure. Signs may include:

hyperinflated (barrel) chest
pursed-lip breathing
use of accessory muscles
reduced breath sounds and wheeze
in advanced disease, cyanosis and signs of right heart failure (cor pulmonale)

Clubbing is not a feature of COPD and should prompt a search for another cause such as lung cancer or bronchiectasis.

Diagnosis

Spirometry is required: a post-bronchodilator FEV₁/FVC ratio below 0.7 confirms persistent airflow limitation.
Severity of airflow limitation (GOLD 1–4) is graded by FEV₁ as % predicted: 80% or more, 50–79%, 30–49%, below 30%.
Chest X-ray: hyperinflation, flattened diaphragms, bullae; also excludes other diagnoses.
Blood tests: full blood count (polycythaemia, anaemia, eosinophil count).
Oxygen saturation, and arterial blood gases if low.

Stable COPD management

Smoking cessation and reducing biomass exposure: the most effective interventions.
Vaccinations, including influenza and pneumococcal.
Pulmonary rehabilitation for symptomatic patients.
Inhaled bronchodilators: long-acting muscarinic antagonists (LAMA) and long-acting beta-agonists (LABA), often in combination. A short-acting bronchodilator is used for rescue.
Inhaled corticosteroids are added mainly for patients with frequent exacerbations and raised blood eosinophils (for example 300 cells/µL or more, per GOLD). They increase the risk of pneumonia.
Long-term oxygen therapy improves survival in patients with chronic severe hypoxaemia (generally PaO₂ 7.3 kPa or less, or 7.3–8.0 kPa with complications such as polycythaemia or cor pulmonale), in non-smokers.
Always check inhaler technique and adherence.

Acute exacerbations

An exacerbation is a worsening of breathlessness, cough or sputum beyond normal day-to-day variation, often triggered by infection. Management includes:

Bronchodilators (nebulised if needed).
A short course of oral corticosteroids.
Antibiotics when sputum becomes purulent or there are signs of infection.
Controlled oxygen targeting saturations of 88–92% in patients at risk of hypercapnia.
Non-invasive ventilation for acute hypercapnic respiratory failure with acidosis (pH below 7.35) despite optimal treatment.

Exam pearls

Too much oxygen in a CO₂ retainer can worsen hypercapnia. Always use a target range and check blood gases.
COPD versus asthma: COPD is less reversible, starts later and is linked to exposure.
Long-term oxygen is not given to people who continue to smoke, because of fire risk.

See also our Acid–Base in 5 Steps article and Exam Night Notes 1.0: Pulmonology.

Test yourself

5 exam-style single-best-answer questions. Choose your answer, then tap “Show answer”.

Which result confirms COPD in a patient with typical symptoms?
1. Hyperinflation on X-ray
2. Pre-bronchodilator FEV1 below 80%
3. Post-bronchodilator FEV1/FVC below 0.7
4. Raised eosinophils
5. Low oxygen saturation
Show answer
Answer: C. Post-bronchodilator FEV1/FVC below 0.7
Persistent airflow limitation is shown by a post-bronchodilator FEV1/FVC ratio below 0.7.
A non-smoking woman who cooked on a wood fire for 30 years has chronic cough and breathlessness. Likely cause?
1. Biomass smoke-related COPD
2. Heart failure
3. Asthma only
4. Lung cancer
5. Sarcoidosis
Show answer
Answer: A. Biomass smoke-related COPD
Biomass fuel smoke is a major cause of COPD in women in low- and middle-income countries.
COPD patient with clubbing. What should you do?
1. Increase inhaler dose
2. Nothing; clubbing is typical of COPD
3. Look for another cause such as lung cancer or bronchiectasis
4. Give oxygen
5. Start steroids
Show answer
Answer: C. Look for another cause such as lung cancer or bronchiectasis
Clubbing is not a feature of COPD and should prompt investigation for another cause.
What oxygen saturation target is used in COPD patients at risk of hypercapnia?
1. 88–92%
2. 94–98%
3. Below 80%
4. 80–85%
5. 98–100%
Show answer
Answer: A. 88–92%
Controlled oxygen with a target of 88–92% reduces the risk of worsening hypercapnic respiratory failure.
Which intervention most changes the long-term course of COPD in a smoker?
1. Antibiotics
2. Mucolytics
3. Theophylline
4. Inhaled steroids
5. Stopping smoking
Show answer
Answer: E. Stopping smoking
Smoking cessation slows the decline in lung function more than any drug.

Disclaimer

For education and exam preparation only. This is not medical advice and must not be used to diagnose or treat patients. Always follow current clinical guidelines and the advice of qualified senior colleagues.

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