Obstructive Lung Disease - Asthma Flashcards
What’s the age demographic of people who get asthma? Of people who have asthma?
Most people with asthma are > 18 years old, but most start having the syndrome during childhood.
4 aspects of the modern definition of asthma?
Chronic airway inflammation.
At least partially reversible.
Airway hyperreactivity.
In some patients, persistent changes in airway structure.
Race-based disparities in asthma?
The rate per capita is much higher in African American and Latino populations vs. whites, and the asthma these groups get tends to be more severe.
I thought asthma was supposed to be “reversible.” What’s the deal with permanent changes in asthma?
Inflammation, especially during exacerbations, can lead to airway smooth muscle hypertrophy and matrix deposition.
3 main pathophysiological processes in asthma?
Treatment that targets it?
Bronchospasm (smooth muscle dysfunction)- beta agonists etc..
Inflammation - inhaled corticosteroids.
Airway hyperresponsiveness.
Asthma exacerbations can permanently worsen lung function.
We should try to prevent them, then.
Say you’re exposed to an allergen and have an allergen exacerbation. What are the phases of response to this?
What implications does this have for therapy?
First, bronchospasm.
Later (20ish - 36 hours), inflammation with PMNs, then eosinophils and monocytes.
So if you just treat with a bronchodilator, there may be symptomatic relief, but inflammatory damage will be continuing.
(especially if still being exposed to the antigen)
(not that important) We used to blame only the Th2 CD4’s. Was that fair?
No, Th1s and others seem to also be involved with asthma-associated inflammation.
(Th1s are especially important in the inflammation provoked by viruses.)
Do all patients with asthma have progressive disease?
No. Contrast this with COPD, where everyone is on a progressive decline.
Do people out-grow asthma?
No. Patients can have resolution of their symptoms… but the potential for asthma is still there with the right stresses.
3 aspects of making an asthma diagnosis?
Episodic symptoms of obstruction, esp. if triggers identified.
Spirometry shows airflow obstruction.
Exclusion of other diseases.
Two ways to measure lung function in a patient with asthma?
Advantages?
Peak flow - it’s easy.
Spirometry - gives you much more data.
Why can the severity of a person’s asthma be difficult to assess on physical exam?
If they’re not currently having an exacerbation, there might not be much to detect.
4 things that can help you distinguish asthma from COPD?
Reversibility. (suggests asthma)
Evidence of emphysema. (suggests COPD)
Environmental factors. (smoking, dust exposure etc. suggest COPD)
Host succeptibility factors (allergy, atopic stuff suggest asthma).
4 classifications of asthma severity? (need to know!)
Mild intermittent.
Mild persistent.
Moderate persistent.
Severe persistent.
