[2] COPD NO DRUGS Flashcards
What is COPD?
A common, progressive disorder characterised by airflow obstruction, which is not fully reversible and does not change markedly over several months.
What does the umbrella term of COPD encompass?
Emphysema and chronic bronchitis, of which patients can have features of either or both
What is the pathological process in emphysema?
Destruction of terminal bronchioles and distal airspaces, as well as supporting tissue surrounding the small airways
What does the destruction of terminal bronchioles and distal airspaces in emphysema lead to?
The loss of alveolar surface area, and therefore impairment of gas exchange
How does the process of destruction of the terminal bronchiole and distal airspaces in emphysema often progress?
To the development of large redundant airspaces within the lung, called bullae.
What is the result of the destruction of supporting tissue surrounding the small airways in emphysema?
It causes the small airways to close/collapse during expiration when the pressure outside the airway rises
What does the collapse of small airways during expiration in emphysema result in?
Airflow obstruction, particularly affecting the small airways
What does loss of elastic tissue in emphysema lead to?
Hyperinflation of the lungs
Why does loss of elastic tissue in the lungs in emphysema lead to hyperinflation of the lungs?
Because the lungs are unable to resist the natural tendency of the ribcage to expand outwards
How is emphysema defined histologically?
As enlarged airspaces distal to the terminal bronchioles, with destruction of the alveolar walls
On which imaging modality can emphysema often be visualised?
CT
What is chronic bronchitis?
Chronic mucus hypersecretion
What causes chronic mucus hypersecretion in chronic bronchitis?
Inflammation in the large airways, usually due to cigarette smoke, leading to proliferation of mucus producing cells in the respiratory epithelium
What is the clinical consequence of chronic bronchitis?
Chronic productive cough and frequent respiratory infections
How does chronic bronchitis result in airflow obstruction?
Remodelling and narrowing fo the airways
What is the clinical definition of chronic bronchitis?
Cough and sputum production on most days for 3 months of 2 successive years
What are the causes of COPD?
- Smoking
- Occupational exposure
- Air pollution
- Alpha-1 anti-trypsin deficiency
Describe the relationship between air pollution and COPD
Exposure to air pollution over a long period of time can affect how well the lungs work, and some research has suggested it could increase the risk of COPD, however at present the link isn’t conculsive, and research is continuing
What is alpha-1-antitrypsin deficiency (AATD)?
A rare, inherited condition which can cause lung and liver problems
What is the mechanism of disease of AATD?
Patients lack the protective enzyme inhibitor alpha-1-antitrypsin, which makes them more vulnerable to effects of inhaling smoke or other toxic materials like dust, fumes, or chemicals
How is diagnosis of AATD made?
Blood test, which measures the level of alpha-1 antitrypsin
How is AATD managed?
At present, there is no specific treatment, and so treatment is focused around treating the lung and liver conditions if they arise
What are the symptoms of COPD?
- Cough and sputum production
- Wheeze
- Dyspnoea, that is progressive
- Frequent chest infections
What are the investigations into COPD?
- History and examination
- Spirometry
- Chest x-rays
- Blood tests
- Peak flow tests
- Sputum sample
What history features would suggest a diagnosis of COPD rather than asthma?
- Age of onset over 35 years
- Smoking history
- Chronic dyspnoea
- Sputum production
- Minimal diurnal or day-to-day FEV1 variation
What are the examination features of COPD?
- Tachypnoea
- Use of accessory muscles of respiration
- Hyperinflation
- Decreased cricosternal distance
- Reduced expansion
- Resonant or hyperresonant percussion note
- Quiet breath sounds
- Wheeze
- Cyanosis
- Cor pulmonae
What is cor pulmonale defined as?
An alteration in the structure and function of the right ventricle of the heart, caused by a primary disorder of the respiratory system
How fast is the onset of cor pulmonale?
Usually has a chronic and slowly progressing course, however acute onset and worsening can occur