Chronic Obstructive Pulmonary Disease (COPD) Flashcards
investigations in COPD
- spirometry
- ABGs
- plethysmography
- diffuse capacity of CO
- CXR (hyperinflation and bullae formation)
- alpha 1 antitrypsin level
management of COPD
- smoking cessation
- counselling
- SABA –> SAMA –> LABA –> LAMA
- steroids if the patient is Gold D
- pneumococcal and influenza vaccines
- theophylline
- roflumilast
what classification is used for COPD?
Gold guidelines
what do the Gold guidelines assess?
- number of exacerbations
- severity of dyspnoea
- number of hospitalisations
- Stage A to D
interventions that reduce mortality
- smoking cessation
- long-term oxygen therapy
characteristics of COPD
- airflow limitation, not fully reversible
- progressive
- abnormal inflammatory response
- no reversibility
definition of chronic bronchitis
a persistent productive cough (with sputum) for a minimum of 3 consecutive months for at least 2 successive years
populations at risk for chronic bronchitis
middle-aged men who smoke, mainly
emphysema
a lung condition characterised by abnormal permanent enlargement of the air spaces distal to the terminal bronchioles with destruction of their walls
people at risk for developing emphysema
- heavy smokers
- if under 40yo, suspect an alpha-1-antitrypsin deficiency
risk factors for COPD
- smoking
- exposure to irritants (occupational dusts and chemicals)
- pollutants
- infection
- genetic and hyperresponsiveness
effects of smoking on the lung
- interferes with ciliary action
- direct damage to epithelium
- inhibits activity of alveolar macrophages to clear bacteria
how do emphysema and bronchitis obstruct air flow?
Chronic Bronchitis
- mucus plugging
- inflammation and oedema of the bronchioles
- development of fibrosis
- co-existent emphysema
Emphysema:
- loss of lung’s elastic recoil which causes small airways to collapse at the beginning of expiration
morphology of chronic bronchitis
- mucopurulent secretions
- reduced cilia
- higher number of goblet cells
- hypertrophic submucous glands
- congestion
- oedema
- squamous metaplasia & dysplasia
- wall fibrosis
- smooth muscle hyperplasia
- inflammation
types of emphysema
- centriacinar
- panacinar
- paraseptal (associated with infective diseases)
what is a bulla?
a cystically dilated space which is more than 1cm in diameter; these can surround the lesion of interest and if punctured, they can risk pneumothorax
where does centriacinar emphysema affect?
- around respiratory bronchioles
- commonly found in men with chronic bronchitis
- upper lobes
- smokers
where does panacinar affect?
- across the entire acinus
- lower lobes if there is the congenital kind of emphysema
where do bullae appear?
- anterior margins
- apices of the upper lobes
histological features of emphysema
- hyperinflation
- markedly enlarged air spaces
- destroyed alveolar septa
features of bullous emphysema
- young men, smokers
- treated by bullectomy
pathogenesis of emphysema
- protease-anti-protease imbalance
- oxidant-anti-oxidant imbalance
protease - anti-protease imbalance
the increase in proteases cause elastin destruction, leading to emphysema
oxidant - anti-oxidant imbalance
- free radicals in tobacco smoke deplete normal lung antioxidants
- activated neutropils contribute more free radicals
- oxidative injury inactivates antiproteases –> functional a1AT deficiency
