Asthma Flashcards
What are the 3 key characteristic features of asthma
Reversible airflow limitation
Airway hyperresponsiveness
Inflammation of the bronchi
Define asthma
Defined as chronic inflammatory disorder of the airways secondary to type 1 hypersensitivity
Asthma is characterised by intermittent airway obstruction and hyper-reactivity
Asthma is an example of:
a) Obstructive lung disease
b) Restrictive lung disease
a) Obstructive lung disease
What type of hypersensitivity reaction is associated with asthma
Type 1 hypersensitivity reaction
Describe the pathogenesis of asthma
- On insult by the trigger, results in type 1 hypersensitivity reaction causing mast cell degranulation and histamine release
- Mast cell degranulation and histamine causes smooth muscle contraction causing the bronchoconstriction
- Inflammation causes increased bronchial hyper-responsiveness contributing to the bronchoconstriction
- Bronchoconstriction is where the smooth muscles of the airways (the bronchi) contract causing a reduction in the diameter of the airways leading to airflow obstruction
- Bronchoconstriction is often reversible, either spontaneously or with treatment such as salbutamol a bronchodilator.
NOTE: Remember the immune system has to be primed with the trigger i.e. the first exposure primes the immune system so little response however the immune system is now ready to respond when next exposed
Name the two types of asthma
Atopic: extrinsic – triggered by environmental factors
Non-atopic: intrinsic – not caused by exposure to an allergen
Give examples of the triggers for asthma
History of atopy
Aspirin induced
Occupational asthma
Exercise induced
Allergies e.g. house dust mites, animal fur, pollen
What is atopy
Genetic predisposition to IgE mediated allergen sensitivity.
Name the 3 IgE medicated atopic conditions
Asthma
Atopic dermatitis i.e. eczema
Allergic rhinitis i.e. hay fever
Name the symptoms of asthma
SoB
Chest tightness
Expiratory wheeze
Cough (often worse at night)
Diurnal variation (symptoms often worse in the morning)
The cough associated with asthma is worse at what time of the day
At night
Asthma symptoms are often worse at what time of the day
In the morning
Name some of the signs of asthma
Tachypnoea (high RR)
Hyperinflated chest
Hyper-resonance on chest percussion
Use of accessory muscles
Reduced peak expiratory flow rate (PEFR)
How is asthma diagnosed
Clinical diagnosis - history alone is enough
What two investigations can be used to confirm a diagnosis of asthma
Fractional exhaled nitric oxide
Spirometry with bronchodilator reversibility
How does fractional exhaled nitric oxide (FeNO) work in the investigation of asthma
A type of nitric oxide synthases rises in inflammatory cells, particularly eosinophils
The level directly correlates to the level of eosinophilic airway inflammation
What level of fractional exhaled nitric oxide (FeNO) supports a diagnosis of asthma
> 40
What pattern would be present in spirometry for asthma
Asthma is an obstructive lung disease and therefore an obstructive pattern will be seen
“Church steeple form on the flow volume chart
What pattern is shown below (Spirometry results):
Reduced FEV1
Normal FVC
Reduced FEV1/FVC ratio
Obstructive lung pattern
What pattern is shown below (Spirometry results):
Reduced FEV1
Reduced FVC
Normal FEV1/FVC ratio
Restrictive lung pattern
How do we determine if the FEV1 is reduced
<80% of the predicted FEV1 value
How do we determine if the FVC is reduced
<80% of the predicted FVC value
How do we determine if the FEV1/FVC ratio is reduced
< 0.7
What are the two axis of the flow volume chart
Volume (L) - x axis
Flow (L/sec) - y axis
The spirometry results for asthma are reversible with bronchodilators. What bronchodilator is used
Salbumtaol
The spirometry results for asthma are reversible with bronchodilators.
What value is improved with a bronchodilator
FEV1 improve which in turn improves the FEV1/FVC ratio
Asthma is chronically managed with inhaler.
What is a non-pharmacological aspect of managing asthma
Help to quit smoking.
Avoid precipitants/triggers
Patients are given two types of inhaler in the chronic management of asthma.
Name these two types
Reliever inhalers
Preventer inhaler
Give an example of a reliver inhaler for managing chronic asthma
Short acting beta agonist (SABA) e.g. salbutamol
When should reliever inhalers (As part of the management of asthma) be used
Used when needed to quickly relieve asthma symptoms for a short time. Should only be used occasionally as too much salbutamol can cause sudden death.
How many times a week of reliever inhaler use would you consider ‘stepping up’ therapy.
Three times a week
Which type of inhaler should be used daily even in the absence of asthma symptoms?
a) Reliever inhalers
b) Preventer inhalers
b) Preventer inhalers
When should SABA be consider as a monotherapy in the management of asthma
For those with infrequent exacerbations and normal lung function.
What is the first line preventer inhaler in the management of asthma
Inhaled corticosteroids (ICS)
What is the second line inhaler management of asthma
ICS + Leukotriene receptor antagonist (LTRA)
What is the third line inhaler management of asthma
ICS + Long acting beta agonist (LABA) +/- LTRA
Keeping LTRA depends on the responsiveness they have been to this medication. If not, remove
What is the fourth line inhaler management of asthma
Maintenance and reliver therapy (MART) +/- LTRA
Keeping LTRA depends on the responsiveness they have been to this medication. If not, remove
Give an example of a short acting beta 2 agonist (SABA)
Salbutamol
When is SABA used in the management of asthma
The first-line drug to be used in the reliever management of asthma
Can be used as a monotherapy management option in cases of very mild asthma however commonly it is used alongside preventer inhaler(s)
What is a potential side effect of SABA
Tremor
What is the target of SABA
beta 2 adrenergic receptor, which are located in the bronchioles of the lungs
Why is it important that the beta agonist used in the manage of asthma is specific to beta 2 adrenergic receptors
To limit off target effects of the medication
There are two types of beta adrenergic receptors: Beta 1 and beta 2
Beta 1 are found in the heart and stimulation of these increases the heart rate and contractibility
Beta 2 receptors are located in the bronchioles of the lungs
There are two types of beta adrenergic receptors: Beta 1 and beta 2.
Where are beta 1 receptors located and what are their function?
Beta 1 are found in the heart and stimulation of these increases the heart rate and contractibility
There are two types of beta adrenergic receptors: Beta 1 and beta 2.
Where are beta 2 receptors located and what are their function?
Beta 2 receptors are located in the bronchioles of the lungs
What inhaler are patients referring to when they say “blue inhaler” - used in asthma
Salbutamol (SABA)
Give an example of the inahled corticosteroids (ICS)
[management of asthma]
Beclometasone
Fluticasone propionate
At what stage in the management of asthma are inhaled corticosteroids (ICS) inhaler used
It is the 1st line preventer inhaler
Used alongside SABA (SABA is for symptom relief but no long term effects)
What a potential side effect of inhaled corticosteroids (ICS) inhaler
[management of asthma]
Oral candidiasis
Shunted growth in children
Give an example of a long acting beta 2 agonist (LABA)
Salmeterol
When should LABA be used in the management of asthma
When asthma is not controlled with just ICS and LTRA
- SABA is used as well but that is for symptom relief instead*
- When adding LABA check whether there is adequate response to LTRA as that can removed if it is not working*
Give an example of a Leukotriene receptor antagonist
Monteleukast
Describe the step wise approach to preventer inhaler asthma therapy regimen
- Used every day to prevent asthma symptoms from occurring.
- 1st line: Inhaled corticosteroids (ICS)
- 2nd line: ICS + Leukotriene receptor antagonist (LTRA)
- 3rd line: ICS + Long acting beta agonist (LABA) +/- LTRA
- 4th line: Maintenance and reliver therapy (MART) +/- LTRA
How is Leukotriene receptor antagonists given
Oral tablet
When during the asthma preventer inhaler step wise regimen is leukotriene receptor antagonists added
Added if there asthma is not controlled with ICS alone
What is the first step of preventer inhaler regimen in managing asthma
Inhaled corticosteroids (ICS)
Alongside SABA (For symptom relief)
What is the second step of preventer inhaler regimen in managing asthma
Inhaled corticosteroids (ICS) + Leukotriene receptor antagonist (LTRA)
Alongside SABA (For symptom relief)
What is the third step of preventer inhaler regimen in managing asthma
Inhaled corticosteroids (ICS) + Long acting beta agonist (LABA) +/- Leukotriene receptor antagonist (LTRA)
Alongside SABA (For symptom relief)
Only continue LTRA if they are responsive to it. Otherwise remove.
What is the fourth step of preventer inhaler regimen in managing asthma
Maintenance and reliver therapy (MART) +/- Leukotriene receptor antagonist (LTRA)
Alongside SABA (For symptom relief)
Only continue LTRA if they are responsive to it. Otherwise remove.
Give an example of a Maintenance and reliever therapy (MART)
[managing chronic asthma]
Turbohaler
What is Maintenance and reliever therapy (MART)
Combination of ICS and fasting-acting LABA
Define acute asthma
It is an acute episode of worsening asthma exacerbation
Characterised by worsening dyspnoea, wheeze and cough that is not responding to salbutamol
Medical emergency
Acute asthma is categoried into 4 categories.
Name them
Moderate
Severe
Life-threatening
Near-fatal
What is the peak expiratory flow rate (PEFR) that would categories someone in the moderate acute asthma class
PEFR 50-75% best or predicted
What is the peak expiratory flow rate (PEFR) that would categories someone in the severe acute asthma class
PEFR 33-50% best or predicted
What is the peak expiratory flow rate (PEFR) that would categories someone in the life threatening acute asthma class
PEFR <33% best or predicted
What are the 4 medications used in the initial management of acute asthma
SABA nebules e.g. salbutamol, terbutaline
LAMA (long acting muscarinic antagonist) nebules e.g. Ipratropium
Oxygen (if hypoxaemic)
Steroids (either oral prednisolone or IV hydrocortisone)
Give two example of SABA nedules that can be used in the initial treatment of acute asthma
Salbutamol and Terbutaline
How does SABA nedules help in the initial treatment of acute asthma
Relieves bronchospasm
SABA is used in the initial treatment of acute asthma.
What two ways can it be given
Metered-dose inhaler or nebuliser
Give an example of LAMA nedules that can be used in the initial treatment of acute asthma
LAMA - Long acting muscarinic antagonist
Ipratropium
How does LAMA nedules help in the initial management of acute asthma
Combining nebulised ipratropium bromide with a nebulised β2 agonist produces significantly greater bronchodilation than β2 agonist alone, leading to faster recovery and shorter duration of admission.
In what patients group should oxygen be used in the initial management of acute asthma
Used in patient is hypoxaemic (common in acute asthma)
What is the maintenance target for oxygen in patient suffering from acute asthma attack
SpO2 level of 94–98%
Give an example of an oral steroid that is used as part of the initial management of acute asthma attack.
oral prednisolone
Give an example of an IV steroid that is used as part of the initial management of acute asthma attack.
IV hydrocortisone
How long should steroids be used in the management of acute asthma attack
Continue until recovery (minimum 5 days)
In cases where IV hydrocortisone has been used, switch to oral prednisolone when appropriate
Second line therapies are used in patient who do not improve after 15 minutes of initial treatment or if there are life threatening features present.
Name two second line therapies
IV magnesium sulphate
IV aminophylline (only following consultation with senior clinicians)
Referral to senior clinicians are ICU team for intubation and ventilation
Describe how IV mangesium sulphate is used as a second line therapy for acute asthma attack
Single dose
Evidence to suggest magnesium sulphate has bronchodilator effects.
Name the two types of Positive airway pressure (PAP)
BiPAP and CPAP
In what type of respiratory failure is BiPAP used and how does it help?
Bi-level positive airway pressure
Delivers higher air pressure during inspiration
Useful for remove CO2 retention and thus Type 2 respiratory failure
In what type of respiratory failure is CPAP used and how does it help?
Continuous positive airway pressure
Delivers same air pressure in inspiration and expiration
Useful for Type 1 respiratory failure
COPD vs Asthma:
What age is it seen in
COPD: over 35s
Asthma: Any age
COPD vs Asthma:
Which one does dyspnoea varies
Asthma - usually acute episodes of exacerbation
COPD it is do not vary much
COPD vs Asthma:
Which one is dyspnoea common at rest
Asthma
COPD vs Asthma:
Which one is associated with a smoking history
COPD definitively
In asthma it could be a trigger but it has variable association
COPD vs Asthma:
Which one has commonly a morning cough
COPD
COPD vs Asthma:
Which one is commonly a noctural cough
Asthma
COPD vs Asthma:
Which one has a family history of the condition as a risk factor
Asthma
COPD vs Asthma:
Which one is commonly associated with atopy
Asthma
