Case 2: Asthma Flashcards
What is Asthma?
A disease of diffuse airway inflammation caused by a variety of triggering stimuli resulting in partially or completely reversible bronchoconstriction
What is the aetiology of Asthma?
Multifactorial, and depends on the interaction among multiple susceptibility genes and environmental factors.
Asthma aetiology is classified as intrinsic (allergy) and extrinsic factors.
Atopy and allergy- atopy describes a group of disorders that run in families.
Environmental factors- early childhood exposure to allergens and maternal smoking.
Occupational sensitisers- over 250 materials can cause asthma.
Drugs such as beta-blockers.
What is the pathophysiology of asthma?
The flow of sequelae occurs as follows:
Bronchoconstriction→airway oedema and inflammation → airway hyper-reactivity→airway remodelling.
Airway inflammation and airway (or bronchial) hyper-responsiveness to various inhaled stimuli lead to symptoms related to reversible airway obstruction.
Airway obstruction is caused by bronchospasm and inflammatory changes such as airway wall oedema and mucus hypersecretion.
Which symptoms does a patient with well-controlled asthma have?
A person with well-controlled asthma should be able to go about their daily activities with no symptoms, and should not be affected. They are typically asymptomatic between
exacerbation
How do you diagnose Asthma?
The flow of investigation, if asthma is suspected:
On Spirometry for FVC and FEV1:
If FVC is normal/decreased
FEV 1 is lower than expected
FEV1/FVC is <0.7
Bronchodilator challenge: >12% improvement in FEV1 and/or >10% of
predicted FEV1 = reversible airway disease
What are the 3 important questions to ask a patient at their annual asthma review?
In the last month/week have you had difficulty sleeping due to your asthma (including cough symptoms, shortness of breath)?
Have you had your usual asthma symptoms (eg, cough, wheeze, chest tightness, shortness of breath) during the day?
Has your asthma interfered with your usual daily activities (eg, school, work, housework)?
It is a regular review done each year, usually by the practise nurse, or by the person in the practice with the most suitable training, which can sometimes be the GP.
Of course, presentation to the GP with other problems can be an opportunity to check on asthma symptoms. Reviews can be done more often if necessary.
Can patients with asthma exercise?
Exercise is not always a trigger.
Such patients should be advised to carry their bronchodilator inhaler (usually a short-acting Beta 2 agonist agent which is usually blue colour coded), with them and then take an additional dose in advance if physical activity is known to precipitate an attack.
Why is it particularly important to have the flu vaccination when you have asthma?
What other vaccinations would you recommend for patients with chronic asthma?
Though people with asthma are not more likely to get the flu, influenza (flu) can be more serious for people with asthma, even if their asthma is mild or their symptoms are well-controlled by medication.
This is because people with asthma have swollen and sensitive airways, and influenza can cause further inflammation of the airways and lungs.
Influenza infection in the lungs can trigger asthma attacks and a worsening of asthma symptoms. It also can lead to pneumonia and other acute respiratory diseases.
A one-off vaccination against Pneumococcal disease is also recommended in asthma.
What are the asthmatic triggers?
House dust mites Animal fur Cold Chest infections Pollen Cigarette smokes Stress Anxiety Allergies Some people have exercise-induced asthma Some people have atopy asthma so they get other reactions like eczema and hayfever.
What are the characteristics of asthma?
Airflow limitation which is usually reversible spontaneously or with treatment.
Airway hyperresponsiveness to a wide range of stimuli
Bronchial inflammation with T lymphocytes, mast cells, eosinophils with associated plasma exudation, oedema, smooth muscle hypertrophy, matrix deposition, mucus plugging and epithelial damage.
Who is the typical asthmatic patient?
Often starts in childhood between the ages of 3 and 5 years and they either worsen or improve during adolescence.
More common in males before puberty and in females thereafter…
What are the major symptoms of asthma?
Recurrent episodes of wheezing, breathlessness, chest tightness and cough, particularly at night and/or in the early morning.
Diagnosis of Asthma
There is no GOLD standard for asthma diagnosis.
1) A history of recurrent episodes (attacks) of symptoms ideally corroborated by variable peak flow when symptomatic and asymptomatic.
- Symptoms that vary over time
- Recorded observation of wheeze heard by a healthcare professional
- Personal/family history of other atopic condition (atopic eczema/dermatitis, allergic rhinitis)
2) Compare the results of diagnostic tests (PEFR and spirometry) undertaken when a patient is symptomatic and asymptomatic
3) Spirometry to demonstrate airway obstruction- obstructive spirometry with positive bronchodilator reversibility increases the probability of asthma.
Investigations for asthma diagnosis
PEFR measurements on waking, prior to taking a bronchodilator and before bed after a bronchodilator are useful in demonstrating the variable airflow limitation.
Exercise tests- used in kids.
Histamine or methacholine bronchial provocation test- indicates the presence of airway hyperresponsiveness, a feature in people with asthma.
- Diffusing capacity for CO
- Trial of corticosteroids-improvement suggests asthma.
* 15% improvement in FEV (spirometry) or PEFR following the usage of bronchodilator is used to diagnose asthma.
Classification of asthma
Intermittent
Mild persistent
Moderate persistent
Severe persistent
