Asthma Flashcards
Definition of asthma.
A chronic inflammatory disorder of the airways.
In susceptible individuals, inflammatory symptoms are usually associated with widespread but variable airflow obstruction and an increase in airway response to a variety of stimuli. Obstruction is often reversible, either spontaneously or with treatment.”
- British Thoracic Soc.
Why are stimuli known as triggers for asthma?
The stimuli are known as triggers because they trigger the asthma attack or trigger bronchoconstriction.
What is the underlying pathology of asthma?
Inflammation of the bronchial tree with hyper-reactivity of the lungs to stimuli.
Long term changes can occur in those having chronic asthma, causing structural changes to the actual airways themselves aka airway remodeling.
List some structural changes which can occur.
Sub-epithelial fibrosis Increased smooth muscle mass Enlargement of submucosal glands Neovascularisation Epithelial alterations
List some stimuli which can trigger asthma.
Allergens
Infections - URT infection
Pollutants - cigarette smoke, sulpher dioxide, nitrous oxides
Weather - cold air/pollen
Occupational - working with chemicals/ particles
Drugs - NSAIDs
Exercise - due to loss of heat and moisture
Stress
What is episodic/seasonal asthma?
Occurs at intervals throughout year e.g. pollen season.
What is chronic asthma?
Persistent disease state with acute exacerbations periodically.
What is exercise induced asthma?
Airways sensitive to colder, drier air. Also occurs due to loss of moisture and heat.
What is childhood asthma?
Asthma due to allergic reactions during childhood. Resolves as child ages.
What is late-onset asthma?
Asthma presenting for first time in adults.
- common in female patients - need higher doses of ICS to control.
What is Status asthmaticus (severe acute asthma)?
A long-lasting severe acute attack. Aggressive early treatment needed.
What is extrinsic asthma?
Allergy or IgE related asthma.
What is intrinsic asthma?
Non-IgE related asthma.
What is the effect on parasympathetic and sympathetic stimulation on wairways?
Parasympathetic stimulation causes bronchoconstriction.
Sympathetic stimulation causes bronchodilation.
What are some symptoms of asthma for diagnosis (can be misdiagnosed due to many respiratory conditions having same symptoms)?
Wheezing, shortness of breath, chest tightness, cough
Name some objective tests which can be used to diagnose and monitor progress of asthma.
Peak expiratory flow test Reversibility tests FeNO test Skin tests Chest radiographs
How do you measure PEF and what does it tell you?
Use Peak Flow Meter.
Device tells you the maximum rate at which you can expel air from lungs.
What are some non-pharmacological treatments for asthma?
Avoidance of triggers, desensitisation to specific allergen (immunotherapy), house dust mite control, smoking cessation, weight reduction.
Stimulation of B2 receptors increases cAMP. What is the effect of this?
Leads to airway relaxation.
What is a major advantage of using combination inhalers?
They aid adherence and ensure that ICS is not taking without a LABA.
Which LABA has a similar onset of action to salbutamol?
Formoterol.
Rapid onset like salbutamol.
What are some adverse effects of B2 adrenoceptor agonists?
Tachycardia, tremor, cramps, hypokalaemia.
Give advantages of using spacer devices.
Creates space between inhaler and oropharynx - gives patient more time to inhale.
Removes need for synchronisation.
Are product specific.
Give the disadvantages of using spacer devices.
Very bulky to carry (but bigger the better).
Distance between spacer and oropharynx - drug is deposited in spacer - doesn’t reach intended site.
Care must be taken while washing device.
When is a spacer device needed?
For children under 5 with any MDI.
Child under 16 with a steroid MDI.
Describe the cleaning process of spacer device.
Wash monthly only, in detergent and let it air dry.
Wiping interior - electrons will be removed from spacer - will become statically charged so drug particles will be stuck to device - will not enter airways.
If DPI and MDI are used correctly, how much should end up in the oropharynx?
80%.
What can corticosteroid deposition cause? How can patient avoid this?
Cause candidiasis (oral thrush), hoarseness, dysphonia, throat irritation. Reduced by washing mouth after ICS use.
What does the high use of short -acting B2 agonists indicate?
Poor control of asthma - must be checked out.
