Respiratory System >
Chronic Obstructive Pulmonary Disease (COPD)
“Syndrome of irreversible airflow obstruction”
Includes sub-types Chronic Bronchitis & Emphysema
Risk Factors
- Modifiable:
- Smoking (>20 pack year)
- Non-Modifiable:
- Age (>65)
- Lower Socioeconomic Status
- High Pollution Exposure
Aetiology
- Predominantly caused by inhaled toxins
- Genetic predisposition (alpha-1-antitrypsin deficiency)
Pathophysiology
- Chronic Bronchitis:
- Underlying inflammation
- Goblet Cells become hyperactive
- Increased mucous production
- Causes Inflammatory Oedema
- Emphysema:
- Oxidative damage occurs, reducing elastic recoil
- Causes abnormal dilation of airways distal to the terminal bronchioles
Clinical Presentation
- Chronic Bronchitis:
- Productive cough for >3months for 2 successive years
- Blue Bloater presentation
- Central cyansis
- Reduced exercise tolerance
- Abnormal auscultation
- Dyspnea (shortness of breath) at rest
- Emphysema:
- Pink Puffer presentation
- CO2 retention
- Low body mass
- Use of accessory inspiratory muscles
- Barrel chest
- Pursed lips
- Non-productive cough
- Pink Puffer presentation
Investigations
- Bloods:
- Arterial Blood Gas – Chronic type II with decreased O2 and increased CO2
- Imaging:
- Chest X-Ray – Looking for hyperinflated chest or flattened diaphragmatic lines
- CT scan – Looking for bullae and to rule out other diagnosis
- Special:
- Spirometry – Is there a low FEV1:FEV ratio (<70%)?
- Peak Flow
- Sats – Decreased O2 sat of 88-92%
- Sputum sample
- On Examination
- Increased respiratory rate
Management
- Conservative:
- Smoking cessation – possible use of Varenicline to aid cessation
- Medical:
- Combined LABA and LAMA inhalers
- Combined LABA, LAMA and GCS inhalers
- Oxygen therapy via Venturi Mask to 88-92% Sat (do not go above 92% to avoid reperfusion damage)
- Surgical:
- Volume resection – removal of emphysemic tissue to provide space for remaining tissue to expand into
Complications
- COPD Exacerbation (Viral / Bacterial)
- Medication non-compliance
- Malignancy
- Pulmonary Embolism
- Pneumothorax