What is asthma?
A chronic disorder characterised by airway wall inflammation and re-modelling
What kind of pulmonary disorder is asthma?
Reversible airflow obstruction
What happens to airways in asthma?
- Thickened smooth muscle
- Thickened basement membranes
What is the pathological process in asthma?
Triggers cause airway smooth muscle to contract
What is the result of airway smooth muscle contraction in asthma?
- Reduced airway radius
- Increased resistance
- Reduced airflow
Describe the prevalance of asthma
- Increasing in prevalence
- More common in developed world
- Increasing in populations who move from developing to developed countries
How many people in the UK currently recieve treatment for asthma?
- 1.1 million children
- 4.3 million adults
What are the potential causes of asthma?
- Genetic risk
- Sensitisation to airborne allergens
- Hygeine hypothesis
What airborne allergens are assoicated with asthma?
- House Dust Mite
- Air pollution
- Tobacco smoke (Pre/post-natal exposure, active)
What kind of diagnosis is asthma?
Why is asthma a clinical diagnosis?
There is no standard investigation of the type, severity, or frequency of symptoms, not of the findings on investigation
What is asthma defined as?
More than one of the symptoms of;
- Chest tightness
- Variable airflow obstruction
Of what nature is the wheeze in asthma?
- High pitched, expiratory sound
What is meant by polyphonic wheeze?
The wheeze is of variable intesity and tone
Where does the wheeze originate in asthma?
In the airways which have been narrowed be compression or obstruction
Of what nature is the cough in asthma?
- Often worse at night
- Exercise induced
What are the potential consequences of an asthmatic cough being worse an night?
- Lack of sleep
- Poor performance at school
What are the potential consequences of an asthmatic cough being exercise induced?
Decreased participation in activities
What does an asthma examination consist of?
What should be inspected when examining for asthma?
- General health
What are you looking for when inspecting the chest during an asthma examination?
- Scars and deformities
- Hyper-expansion (Barrel Chest)
What are you looking for when inspecting general health during an asthma examination?
- Can they speak?
What are you looking for on inspection of the room during an asthma examination?
What sign on percussion is indicative of asthma?
What sign on auscultation is indicative of asthma?
What tests are used to assess the condition of a patient suspected with asthma?
- Spirometry - Flow volume loop
- Allergy testing
- Chest X-rays
What will be shown on a flow volume loop with a patient with asthma?
- Low PEFR
- Low FEV1/FVC ratio
- >12% increase in FEV1 following salbutamol
Draw a flow volume loop illustrating;
- A normal person
- An asthmatic
- An asthmatic with salbutamol
How are allergen tests for asthma carried out?
Skin prick to aero-allergens, e.g. cat, dog, HDM, then assess blood IgE levels
Why are chest x-rays performed in patients suspected to have asthma?
To exclude other diseases, inhalation of foreign body, or a pneumothorax