COPD Flashcards
What are the characteristics of chronic bronchitis
- Affects larger airways (bronchus, larger bronchioles)
- Mucous gland hypertrophy and hyperplasia
- Hypersecretion of mucus
What are the characteristics of emphysema?
- Affects smaller airways (smaller bronchioles, alveoli)
- Air space enlargement
- Alveolar wall destruction
- Loss of elasticity
- Destruction of pulmonary capillary bed
- Increase in inflammatory cells, macrophages, CD8+ lymphocytes
What are the adaptations in chronic bronchitis?
1) Neutrophils in sputum. Inflammatory exudate in lumen
2) Squamous metaplasia of epithelium (no basement membrane thickening)
3) Increased macrophages
4) Increased CD8+ lymphocytes
5) Disrupted alveolar attachments
6) Peribronchial fibrosis
7) Lymphoid follicle
(little increase in airway smooth muscle unlike chronic asthma)
What are the reversible causes of airflow obstruction in COPD?
- Accumulation of inflammatory cells, mucus, and plasma exudate in bronchi
- Smooth muscle contraction in peripheral and central airways
- Dynamic hyperinflation during exercise
What are the irreversible causes of airflow obstruction in COPD?
- Fibrosis and narrowing of the airways
- Loss of elastic recoil due to alveolar destruction
- Destruction of alveolar support that maintains patency of small airways
What are the clinical features of COPD?
- Productive cough (sputum)
- Wheeze
- Breathlessness (dyspnoea)
- Frequent infective exacerbations with purulent sputum
- Signs of respiratory failure, cor pulmonale
“pink puffers” - tachypnoeic, responsive to CO2
Blue - cyanosis, oedema, insensitive to CO2
How is COPD diagnosed?
**Spirometry – reduced FEV1 : FVC ratio
CXR – may show hyperinflation but may be normal
Haemoglobin – may be raised in chronic hypoxia
How is COPD managed?
- Smoking cessation advice
- Bronchodilator therapy
- Combination therapy
- Oral theophylline
- Mucolytic agents
