COPD

Question 1

Mechanisms of Airflow limitation in COPD

Answer 1

1. Mucus hypersecretion: luminal obstruction.
2. Disrupted alveolar attachments: emphysema.
3. Mucosal & peribronchial inflammation & fibrosis (obliterative bronchiolitis).

Question 2

Disease process in COPD

Answer 2

Cigarette Smoke => Alveolar macrophage <=> Neutrophil => Proteases => Emphysema & Chronic Bronchitis => Progressive airflow limitation.

Question 3

Two aspects of COPD

Answer 3

Chronic Bronchitis & Emphysema

Question 4

Chronic Bronchitis

Answer 4

• Chronic Neutrophilic inflammation.
• Mucus hypersecretion.
• Mucociliary dysfunction.
• Altered lung biome.
• Smooth muscle spasm & hypertrophy.
• Partially reversible.

Question 5

Emphysema

Answer 5

• Alveolar destruction.
• Impaired gas exchange.
• Loss of bronchial support.
• Irreversible.

Question 6

Symptoms of COPD

Answer 6

• Productive cough.
• Progressive dyspnoea (SOB)
• Frequent infections.
• Wheezing (Chronic Bronchitis)

Question 7

Signs of COPD

Answer 7

• Reduced Breath sounds (Emphysema)

Question 8

Complications of COPD

Answer 8

Pulmonary hypertension & RV hypertrophy/failure (cor pulmonale)

Question 9

Chronic cascade in COPD

Answer 9

Progressive fixed airflow obstruction => impaired alveolar gas exchange => Resp failure (decreased PaO2, increased PaCO2)

Question 10

COPD History

Answer 10

Smoking

Question 11

Corticosteroids in COPD

Answer 11

May cause pneumonia due to local immune suppression & impaired Mucociliary clearance (especially fluticasone due to prolonged lung retention).

Reduces exacerbations in Eosinophilic COPD (ACO)

Question 12

Oral steroids

Answer 12

Prednisolone used for acute exacerbations.

Question 13

Inhaled steroids

Answer 13

Beclomethasone used for maintenance monotherapy in asthma.

Question 14

Bronchodilators: B2 agonists

Answer 14

Stimulate bronchial smooth muscle B2 receptors: Increased cAMP.

SABA or LAMA.

LAMA/LABA or ICS/LABA/LAMA used.

Question 15

Bronchodilators: Muscarinic Antagonists (anti-cholinergics)

Answer 15

Block post-junctional end plate M3 receptors.

SAMA (Ipratropium) & LAMA (Tiotropium)

Chronic: LAMA or LAMA/LABA or ICS/LAMA/LABA. To reduce exacerbations.

Acute: High Nebulised doses of ipratropium.

Question 16

Route of Administration of SAMA & LAMA

Answer 16

Inhalation

Question 17

Bronchodilator/Anti-inflammatory: Methylxanthines

Answer 17

Non-selective phosphodiesterase inhibitor (increased cAMP). Also acts as adenosine antagonist.

Chronic:

• Oral (theophylline).
• Used as add-on with ICS.

Acute:
- IV (aminophylline)

Question 18

Anti-inflammatory: PDE4 inhibitors

Answer 18

Anti-inflammatory action & reduces exacerbations.

E.g. Oral roflumilast.

Used as add-on to LABA or LAMA/

Question 19

Adverse effects of Roflumilast (PDE4 inhibitor)

Answer 19

Nausea, diarrhoea, headache, weight loss.

Question 20

Mucolytics

Answer 20

Reduce sputum viscosity. aid sputum expectoration & reduce exacerbations.

E.g. Oral carbocisteine & erdosteine.

Question 21

Non-pharmacological treatment for Chronic COPD

Answer 21

• Smoking cessation.
• Influenza/pneumococcal immunisation.
• Physical activity.
• Domicilary oxygen.

Question 22

Pharmacological treatment of Chronic COPD

Answer 22

• LABA/LAMA combo.
• ICS/LABA/LAMA combo (if high eosinophil count).
• Roflumilast.
• Carbocisteine.
• Antibiotics for infections - Azithromycin.

Question 23

Treatment of Acute COPD

Answer 23

• Nebulised high dose SABA (Salbutamol) + SAMA (Ipratropium).
• Oral prednisolone.
• Antibiotic (amoxicillin/doxycycline) if infection.
• Oxygen: 24-28% titrated against PaO2/PaCO2.
• Physio to aid sputum expectoration.
• Non-invasive ventilations.
• ITU assisted ventilation if reversible component (e.g. pneumonia)