Summary
COPD is an umbrella term for
several diseases characterised by
airflow obstruction, most commonly
chronic bronchitis and
emphysema, but also including bronchial
asthma and brochiectasis.
COPD is distinguished from restrictive pulmonary disease, a group of disorders characterised by decreased lung capacity due to either chest wall or skeletal abnormalities, where FEV1 and FVC are both decreased proportionately, resulting in a normal FEV1:FVC.
- In COPD the FEV1:FVC ratio is <70%
General info
Epidemiology
- Prevalence is approximately 1.5 million and mortality is 23,000/year in the UK
- By 2020 it is likely to be the 3rd highest cause of death worldwide
- Smoking accounts for 90-98% of all cases
- Number of cases has stabilised in men, but is rising among women
- Most commonly seen in ex-smokers > 35 years of age
- COPD is unlikely to develop with a smoking history less than 10 pack years
- Low socioeconomic status and low birth weight are predisposing factors
Causes
- Smoking
- Coal mining
- Genetic, i.e. α1 –antitrypsin deficiency causes emphysema
Signs and symptoms
- Tachypnoea
- Use of accessory muscles of respiration
- Hyperinflation caused by gas trapping
- Reduced cricosternal distance , <3cm
- Reduced chest expansion
- Resonant chest sounds
- Quiet breath sounds over areas of emphysematous bullae
- Wheeze
- Cyanosis
- Cor pulmonale
