3. Chronic Obstructive Pulmonary Disease (COPD)

📄Definition

Persistent airflow obstruction that is not fully reversible due to chronic inflammation from smoking or environmental exposure.

Includes:

  • Chronic bronchitis: productive cough ≥3 months for ≥2 consecutive years

  • Emphysema: alveolar wall destruction & airspace enlargement

 

🔬Pathophysiology

  • Inhaled irritants (e.g. smoke) → inflammation → mucus hypersecretion + alveolar destruction

  • Leads to air trapping, reduced gas exchange, and increased work of breathing

🎯 EXAM ANCHOR – CORE CONCEPT (PARA)

  • COPD = Persistent airflow obstruction that is not fully reversible

  • Caused by chronic exposure (usually smoking)

  • Includes chronic bronchitis and emphysema

📌 PARA commonly asks:
Which respiratory condition causes irreversible airflow obstruction?

👉 Answer: COPD

🛡️Risk Factors

Mnemonic: SCARE
Smoking (most important)
Cooking fuel/air pollution (biomass exposure)
Alpha-1 antitrypsin deficiency
Repeated childhood infections
Environmental/occupational exposure (e.g. coal, dust)

📋Clinical Features 

Mnemonic: COUGHED
Chronic productive cough
Overexertion causes dyspnoea
Unusual wheeze
Gradual onset of symptoms
Hyperinflated chest
Exercise limitation
Daily sputum production

📊 Diagnosis

Confirmed by spirometry

  • Post-bronchodilator FEV₁/FVC <0.7 (fixed obstruction)

  • No full reversibility (contrast with asthma)

🎯 EXAM ANCHOR – DIAGNOSIS (PARA)

  • Spirometry is required to diagnose COPD

  • Post-bronchodilator FEV₁/FVC < 0.7

  • Obstruction is fixed (no full reversibility)

📌 PARA commonly asks:
Which spirometry finding confirms a diagnosis of COPD?

👉 Answer: Post-bronchodilator FEV₁/FVC < 0.7

Other investigations:

  • CXR: rule out malignancy, assess hyperinflation

  • Alpha-1 antitrypsin: if <40 yrs or FHx

  • FBC: polycythaemia (from chronic hypoxia)

  • Sputum culture: if recurrent exacerbations

🎯 EXAM ANCHOR – ASTHMA vs COPD (PARA)

  • Asthma → reversible airflow obstruction

  • COPD → irreversible airflow obstruction

  • Smoking history strongly favours COPD

📌 PARA commonly asks:
Which feature best differentiates COPD from asthma?

👉 Answer: Lack of reversibility on spirometry

🩻 CXR Findings

Mnemonic: HEAVES
Hyperinflated lungs
Elongated heart shadow
Attenuated vessels (vascular markings ↓)
Vertical heart
Emphysematous bullae
Small peripheral markings (loss of definition)

🎯 EXAM ANCHOR – IMAGING (PARA)

  • CXR may show hyperinflation or bullae

  • Imaging does not confirm COPD

  • Diagnosis must be made with spirometry

📌 PARA commonly asks:
Can a chest X-ray confirm a diagnosis of COPD?

👉 Answer: No

Severity 

Based on FEV₁ % predicted:

SeverityFEV₁ %Description
Mild≥80%Often underdiagnosed
Moderate50–79%Symptoms with exertion
Severe30–49%Symptoms at rest
Very Severe<30%Risk of respiratory failure
 

Also use MRC Dyspnoea Scale (Grade 1–5) to assess breathlessness:

GradeDegree of Breathlessness
1Not troubled by breathlessness except on strenuous exercise.
2Short of breath when hurrying or walking up a slight hill.
3Walks slower than contemporaries on level ground or has to stop for breath when walking at own pace.
4Stops for breath after walking about 100 metres or after a few minutes on level ground.
5Too breathless to leave the house, or breathless when dressing or undressing.

🎯 EXAM ANCHOR – SEVERITY & SYMPTOMS (PARA)

  • FEV₁ % predicted assesses airflow limitation

  • MRC dyspnoea scale assesses symptom burden

  • Treatment escalation is guided by symptoms and exacerbations

📌 PARA commonly asks:
Which tool is used to assess breathlessness severity in COPD?

👉 Answer: MRC dyspnoea scale

Management 

Mnemonic:  STOP 

Smoking cessation – most important

🎯 EXAM ANCHOR – MOST IMPORTANT INTERVENTION (PARA)

  • Smoking cessation is the single most effective intervention

  • Slows disease progression

  • Improves survival

📌 PARA commonly asks:
What is the most important intervention to slow COPD progression?

👉 Answer: Smoking cessation

Terbutaline/Salbutamol (SABA) or Ipratropium (SAMA) for quick relief.
Oxygen (LTOT) if PaO₂ ≤7.3 kPa (or ≤8.0 kPa with peripheral oedema, polycythaemia, or pulmonary hypertension.)

🎯 EXAM ANCHOR – LONG-TERM OXYGEN THERAPY (LTOT) (PARA)

  • Indicated in stable COPD if:

    • PaO₂ ≤7.3 kPa (or ≤8.0 kPa with complications)

  • Improves survival in chronic hypoxia

  • To qualify for LTOT, the patient must have stopped smoking.
  • Providing oxygen to a current smoker is a major fire risk and a common ‘Safety Trap’ in the exam.

📌 PARA commonly asks:
What arterial oxygen threshold indicates long-term oxygen therapy in COPD?

Pulmonary rehab for MRC ≥3

Mnemonic: BREAD

Bronchodilators (The “Two-Path” Step):

Path A: No Asthmatic FeaturesPath B: With Asthmatic Features
First Line: LABA + LAMAFirst Line: LABA + ICS
(e.g. Aclidinium/Formoterol)(e.g. Salmeterol/Fluticasone)
↓↓
If still symptomatic:If still symptomatic:
LABA + LAMA + ICS (Triple Therapy)LABA + LAMA + ICS (Triple Therapy)

Rescue Pack (Steroids + Antibiotics for home use).

Exacerbation management (5 days Prednisolone/5 days Antibiotics).

Alpha-1 Antitrypsin screening (if young/non-smoker).

Diet/BMI monitoring (NICE emphasizes nutrition in chronic lung disease).

Exacerbation Management

Mnemonic: COPD-X

C — Controlled Oxygen

  • Target SpO₂ 88–92%

  • Use Venturi mask (or nasal cannula if stable)

  • Repeat ABGs if severe, drowsy, or hypercapnia suspected

🎯 EXAM ANCHOR – OXYGEN (PARA)

📌 PARA commonly asks:
A patient with known COPD presents with an acute exacerbation. What oxygen saturation target should be used?

👉 Answer: 88–92%

O — Optimise Bronchodilators

  • Duonebs: salbutamol or ipratropium (neb or inhaler with spacer)

  • Increase frequency during acute phase

🎯 EXAM ANCHOR – BRONCHODILATORS (PARA)

📌 PARA commonly asks:

What is the first-line bronchodilator regimen in an acute COPD exacerbation?

👉 Answer: Short-acting β₂-agonist or short-acting muscarinic antagonist (salbutamol or ipratropium)

D — Decide Antibiotics (If Indicated)

Give antibiotics only if infective features present:

  • ↑ sputum purulence

  • ± ↑ sputum volume

  • ± ↑ dyspnoea

  • Send sputum culture if severe or recurrent exacerbations

🎯 EXAM ANCHOR – ANTIBIOTICS (PARA)

📌 PARA commonly asks:

Question:
When are antibiotics indicated in an acute COPD exacerbation?

👉 Answer: Antibiotics if increased sputum purulence PLUS (increased dyspnoea OR increased sputum volume).

X — eXclude Complications & Escalate Care

  • CXR to exclude pneumonia or pneumothorax

  • Admit if confusion, cyanosis, worsening hypoxia, exhaustion, or haemodynamic instability

  • Consider NIV if persistent hypercapnic respiratory acidosis despite optimal medical therapy

🎯 EXAM ANCHOR – NIV (PARA)

📌 PARA commonly asks:

Question:
When should non-invasive ventilation (NIV) be considered in an acute COPD exacerbation?

👉 Answer: Persistent hypercapnic respiratory acidosis despite optimal medical therapy

Monitoring & Review

  • Annual review (inhaler technique, adherence, symptoms)

  • Monitor MRC dyspnoea scale, exacerbation frequency, BMI

  • Consider home rescue pack (antibiotic + steroid) for frequent exacerbators

❗Complications

Mnemonic: CHAP
Cor pulmonale (right heart failure)
Hypercapnic respiratory failure
Acute exacerbations
Pneumothorax (esp. in bullous disease)

🎯 EXAM ANCHOR – COMPLICATIONS (PARA)

  • Chronic hypoxia → polycythaemia

  • Pulmonary vascular disease → cor pulmonale

  • Bullous disease → pneumothorax

📌 PARA commonly asks:
Which complication of COPD results from chronic hypoxia?

👉 Answer: Cor pulmonale

Differential Diagnoses

Mnemonic: ABC LUNG
Asthma
Bronchiectasis
CHF
Lung cancer
Upper airway obstruction
Neuromuscular disease
GORD-associated cough

🔎  Key PARA Exam Traps – COPD

💡 Post-bronchodilator FEV₁/FVC < 0.7 confirms COPD

💡 Irreversible airflow obstruction (reversible = asthma)

💡 Smoking cessation is the only disease-modifying intervention

💡 ICS not first-line → use only when there are:
• Frequent exacerbations (≥2/year or ≥1 hospital admission) despite bronchodilators, or
• Steroid responsiveness (e.g. asthma history or blood eosinophils ≥300 cells/µL)

💡 Exacerbation O₂ target 88–92% (avoid over-oxygenation)

💡 LTOT only if PaO₂ ≤ 7.3 kPa (stable COPD)

💡 Treatment escalation guided by MRC + exacerbations, not FEV₁ alone

💡 Chronic hypoxia → polycythaemia, cor pulmonale

💡 Sudden deterioration → consider pneumothorax (bullae)

Last updated in line with NICE NG115 (March 2023)
Reviewed for PassMap: Febuary 2026
This content is NICE-compliant and exam-optimised for the Physician Associate Regulation Assessment (PARA).

 

Educational platform. Not medical advice.

 

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