Asthma Flashcards
What is asthma
Reversible airway obstruction largely at the level of the bronchioles.
What causes the obstruction is asthma
Local inflammation of the airway and bronchial hyperactivity leading to resistance to airflow.
What are the symptoms of asthma
- Chest tightness
- Feeling of breathlessness
- Wheeze
- Cough
- May be worse in the morning or at night (diurnal variability)
What are the provoking factors of asthma
- Exercise/hyperventilation
- Food, additives
- Drugs (NSAIDs, beta blockers)
- Cigarette smoke
What happens to a normal airway in asthma
A normal airway becomes very inflamed, swollen and mucus covered, reducing the lumen of the small airways and causing increased resistance to airflow.
What are three ways to treat acute forms of asthma
Oxygen to treat the hypoxia.
Beta 2 agonists to treat the bronchoconstriction
Corticosteroids to treat the inflammation.
What is the role in giving supplementary oxygen in the treatment of acute asthma
This treats the hypoxia. It makes up for problems with V/Q mismatching in the lungs.
What is the role in giving beta 2 agonists to treat acute asthma
Beta 2 agonists are bronchodilators and so rapidly reduce airway obstruction.
Where else can beta 2 agonists act and what side effects can they bring about
Beta 2 agonists are not 100% specific. This means they can act on beta 1 receptors in the heart to bring about increased heart rate or on beta 2 receptors in the muscle to bring about tremor.
How are the side effects of beta 2 agonists reduced
By using topical application by inhaled medication.
How can corticosteroids be given for the treatment of asthma
By the inhaled route or by oral route in acute attacks. Corticosteroids can also be given IV if the patient is too ill to take them by either of these mechanisms.
What is the impact of corticosteroids for acute asthma
They reduce airway inflammation however take a few hours to work.
What is the recommended treatment progression for asthmatics
For the mildest form of asthma where acute exacerbation might be brought about by something like exercise - inhaled short acting beta 2 agonist such as salbutamol.
If symptoms are more frequent the patient will also be offered inhaled corticosteroid treatment.
If the symptoms are still not under control, a longer acting beta 2 agonist will be offered.
If still not under control, a higher dose of steroid inhaler will be given, or possibly other medication such as a leukotriene receptor antagonist or theophylline derivative.
In very severe circumstances - oral corticosteroid therapy.
