COPD Flashcards
What is the major cause of COPD?
Smoking
What is COPD?
Clinical syndrome including emphysema, chronic bronchitis and small airways disease (and some reversible bronchospasm or “asthma”) in varying proportions
Characterised by slow progression and infective exacerbations
List 4 ways smoking predisposes to pulmonary infection
Inhibition of the muco-ciliary escalator
Increased mucus
Inhibition of leukocyte function
Direct damage to the epithelial layer
What are the 2 main presentations of COPD?
Predominant bronchitis (blue bloater) Predominant emphysema (pink puffer)
Describe the pathogenesis of COPD
Cigarette smoke activates alveolar macrophages and airway epithelial cells
Various chemokines are released and attract TH1, NK, CTLs and PMNs
Neutrophils release large amounts of proteases which degrade elastin and lead to apoptosis of cells
Inflammation activates epithelium, fibroblasts and myofibroblasts to promote mucus and collagen production, and cause scarring
Inflammation also induces a squamous metaplasia
What are the characteristic changes in small airways in patients with COPD?
Inflammatory exudate in lumen
Disrupted alveolar attachments
Thickened wall with inflammatory cells and lymphoid follicles
Peribronchial fibrosis
What are the characteristic changes in lung parenchyma in patients with COPD?
Alveolar wall destruction
Loss of elasticity
Destruction of pulmonary capillary bed
Increased inflammatory cells
When does air trapping in COPD occur?
With severe COPD where there is loss of alveolar attachments
How is stable COPD treated?
Bronchodilators
GCS
Antibiotics for infectious exacerbations
Antioxidant agents (?)
What classes of bronchodilators are used in COPD?
B2 agonists (usually LABA)
Muscarinic antagonists
Methylxanthines
How does theophylline work and when is it used in COPD?
Methylxanthine with a number of different actions including PDEI, adenosine antagonism and HDAC2 activation; mechanism of action for COPD is unknown
Used as preventers in COPD
What are the dose-limiting side effects of theophylline?
Nausea and vomiting
Diarrhoea
CNS stimulation (narrow therapeutic range)
Cardiostimulation (dysrhythmias)
Roflumilast
Selective PDEI used as a preventer in COPD
When are COPD patients treated with GCS?
FEV1 <60% (severe and very severe COPD)
Repeated exacerbations
What medications are not recommended in COPD?
Mucolytics
Antitussives (cough suppressants)
Vasodilators
