#142

F.Y.I


COPD is defined as the progressive and incomplete reversible obstruction of the airway.

Eg. of COPD:

- Chronic bronchitis

- Bronchiolitis

- Bronchiestasis

- Emphysema

Inflammatory mechanism
1. Smoke or other irritants activates the macrophages and the epithelial cells of the respiratory tract
2. These cells will release chemotaxic factors (eg. chemokines and leukotrienes)
3. Other inflammatory cells are recruited from the circulation to the airway
4. The release of fibrogenic factors which stimulate fibroblasts to produce fibrosis
5. Some cells release protease which break downs the connective tissue of lung parenchyma and leads to emphysema
6. Hypersecretion mucus
7.  CD8+ cells may play a role in alveolar destruction through induction of apoptosis of type 1 pneumocytes

Severity of COPD depends on the percentage of FEV1 predicted.

Stage 0: At high risk
- chronic symptoms: cough and sputum
- No spirometric abnormalities

Stage 1: Mild COPD
- FEV1/FEC < 70%
- FEV1 ≥ 80%
- At this stage, patients are normally not aware of their abnormal lung function
- Recommended treatment: Short acting bronchodilator PRN

Stage 2: Moderate COPD

- FEV1/FEC < 70%

- 50% ≤ FEV1 <80% predicted
- Shortness of breath typically during exertion
- Recommended treatment: Rehabilitation, Inhaled glucocorticosteroids if significant symptoms and lung function and response, regular treatment with one or more bronchodilators.

Stage 3: Severe COPD

- FEV1/FEC < 70%

- 30% ≤ FEV1 <50% predicted
- Shortness of breath worsen
- Limits daily activities
- Recommended treatment: Rehabilitation, inhaled glucocorticosteroids if significant symptoms and lung function and response, regular treatment with one or more bronchodilators.

Stage 4: Very severe COPD
- FEV1/FEC < 70%
- FEV1 < 30% or FEV1 <50% + chronic respiratory failure
-quality of life is greatly impaire
- exacerbation is potentially life-threatening
- Recommended treatment: Rehabilitation, Inhaled glucocorticosteroids if significant symptoms and lung function and response, regular treatment with one or more bronchodilators, long term oxygen therapy if respiratory failure, treatment of complications, consider surgical options.


Eg. of short acting beta agonist bronchodilators: salbutamol, terbutamine, fenoterol
Eg. of long acting beta agonist bronchodilators: salmeterol, formoterol, arformoterol
Eg. of short acting anti cholinergic: Ipratropium bromide, Oxitropium bromide
Eg. of long acting anti cholinergic: Tiotropium