PH2113 - COPD Flashcards
What is the difference between asthma and COPD?
Asthma is episodic
COPD is chronic
the type of inflammation is different to asthma and this has an impact on the disease progression
What are the symptoms of COPD?
Increasing breathlessness Persistent chesty cough Frequent chest infections - loss of cilia responsible for clearing mucus Persistent wheezing - airway narrowing - oedema - swelling of wall
What is the third largest cause of death from respiratory disease?
Pneumonia (43%)
Respiratory cancer (23%)
COPD (20%)
How has the incidence of COPD changed over the last 10 years?
Incidence of COPD has risen approximately 30% over the last 10 years
describe the symptoms of COPD and asthma
COPD Increasing breathlessness Persistent chesty cough Frequent chest infections Persistent wheezing Symptoms will get progressively worse No hereditary link Presentation older patients Periods where symptoms get much worse (exacerbations) Airway hyper-responsiveness present
Asthma
Episodic breathlessness
Cough associated with asthma episodes
Less increased frequency of chest infections
Episodes of wheezing
Untreated, frequency and severity of symptoms can get worse
Some hereditary links
Presentation at any age
Periods where symptoms get much worse (exacerbations)
Airway hyper-responsiveness present
What proportion of COPD patients are smokers?
~ 90%
What proportion of smokers develop COPD?
15%
What is the pathology of COPD?
Non-reversible air flow obstruction
Dominant inflammatory cell in the lungs in the neutrophil
- in asthma it is the eosinophil
No thickening of the basement membrane, hypertrophy, hyperplasia or airway smooth muscle
Mucus hypersecretion
- can contribute to airway narrowing
Bronchoconstriction
- high parasympathetic tone
Airway hyper-responsiveness
- similar to asthma
Epithelial shedding and damage to cilia (mucus build up)
- similar to asthma
Oedema
- increased access of white blood cells to lung tissue
Damage to the alveolar extracellular matrix leading to irreversible loss of lung elasticity and enlargement of the respiratory air space
- emphysema
What is the key inflammatory cell in COPD?
Neutrophil
What causes COPD?
Cigarette smoke and other irritants
compare the pathology of asthma and COPD
Firstly, the structural changes in the lung is irreversible and there are no pharmacological treatments that can prevent its progression. This is not the case in asthma, were corticosteroids can effectively slow or stop the pathological changes in lung architecture.
Unlike asthma where the predominant inflammatory cell found in the lungs of asthma patients is the eosinophil, for COPD patients it is the neutrophil. There is often some overlap between severe asthma and COPD. Some unfortunate patients have both asthma and COPD at the same time. Severe asthma, as discussed in the optional lesson 5, is associated with a larger population of neutrophils. The neutrophil may partly explain why the inflammation associated with COPD and some types of asthma is less sensitive to treatment with corticosteroids. This is due to the type of corticosteroid receptor found in neutrophils compared to that expressed in eosinophils. View optional lesson 5 for more details.
Distinct from asthma, there is no thickening of smooth muscle in the bronchiole wall. This does not mean the COPD patients are not associated with hyper-responsiveness which is indeed one of the features of COPD. However, thickening of smooth muscle does not play a role in the lungs of COPD patients.
As in some types of asthma, pulmonary inflammation associated with COPD causes a hypersecretion of mucous. This can contribute to the airway obstruction that contributes to the dyspnoea experienced by COPD patients.
Asthma attacks are triggered by exposure to allergens where the response involves IgE. This is not the case in COPD. The best analogy is to consider COPD as an exaggerated irritant response that leads to an inflammatory response.
What is the only intervention which limits COPD progression?
Stopping smoking
What are the non-pharmacological management strategies of stable COPD?
- Smoking cessation
- only proven method to improve life expectancy - Pulmonary rehabilitation
- Long-term oxygen therapy
- Surgery
Strategies 2, 3 and 4 are palliative (relieving pain without dealing with the cause of the condition)
Describe smoking cessation as an intervention for COPD
The most important/effective intervention Slows disease progression DOES NOT RESTORE LOST FUNCTION Sudden cessation better than gradual Big role for pharmacists!
Which COPD intervention can be used in patients who are functionally disabled?
Pulmonary rehabilitation
