Clinical Features of COPD Flashcards
What is the definition of COPD?
Chronic, slowly progressive disorder characterised by airflow obstruction that does not change markedly over several months. Most of the the lung function impairment is fixed, although some reversibility can be produced by bronchodilator (or other) therapy.
What does the definition of COPD not mention?
NO mention of symptoms NO mention of bronchitis or emphysema NO mention of smoking
Why does obstruction of the airways occur?
Small-airway narrowing - and can be worsened by inflammation and mucus, leading to progressive breathlessness on exertion, along with coughing and wheezing.
What causes luminal occlusion?
Secretion of mucus and inflammatory exudate. Thickening of airway wall
What happens to the airway wall?
Thickens
ACOS?
Asthma, COPD, overlap syndrome
What happens to elasticity and alveolar attachments?
Loss of elasticity and disrupted alveolar attachments
What causes COPD (apart from smoking?)
Passive smoking Maternal smoking (Reduces FEV1 and increases respiratory illness) Air pollution Occupation (jobs exposing to dusts, vapours, fumes)
What are the two genotypes for alpha 1 antitrypsin deficiency? (75 variants)
Normal (86% UK) - PiMM Troublesome genotype (PiZZ)
What is the effect of alpha 1 antitrypsin ?
Neutralises enzymes released by neutrophils.
What percentage of smokers develop clinically significant COPD?
20%
What is a normal pack year?
Over 20
What is a pack year?
1 pack year = 1 pack a day for a year
What is the rate of decline of FEV1?
Non-smoker - 30 ml/yr SMOKER - 50 ml/yr
What is your typical COPD patient?
Patient 40+ years, smoker/ex-smoker, breathless on exertion, cough
What are the differential diagnosis for COPD?
COPD Asthma Lung cancer Left ventricular failure Fibrosing alveolitis Bronchiectasis Rarities: TB, recurrent pulmonary emboli