Clinical Obstructive Lung Disease: COPD/Asthma/CF Flashcards
What are the 2 major causes of airflow obstruction?
- Intrinsic airway narrowing (bronchospasm, plugging, inflammation/edema) 2. Floppy airways (decreased radial tethering or decreased airway integrity)
The work of breathing is mainly comprised of the work against what 2 forces?
- resistive forces 2. elastic forces
With hyperinflation, which lung volume(s) are increased?
Functional residual capacity is increased, residual volume is increased, expiratory reserve volume is increased. FRC = ERV + RV
What is asthma?
Asthma is a chronic inflammatory disorder of the airways.
Asthma leads to airway ____ responsiveness
hyper
What are common symptoms of asthma? (name 4)
- recurrent episodes of wheezing
- breathlessness
- chest tightness
- coughing, particularly at night or in the early morning
Asthma episodes are associated with airflow _______
obstruction
What is extrinsic asthma?
Extrinsic asthma is allergic asthma. It is in response to environmental antigens (allergic, occupational, etc). It is mainly IgE mediated
What is intrinsic asthma?
Intrinsic asthma is the nonseasonal, non allergic form of asthma. It tends to be chronic and persistent. It can be post-viral where epithelial injury leads to bronchial narrowing, or it could be due to altered arachidonic acid metabolites (increased leukotrienes, decreased prostaglandings - these patients may have worsening of their asthma if they take aspirin or ibuprofen)
What causes development of asthma?
The causes of asthma aren’t really known but it is thought to be multifactorial.
- genetic predisposition
- gender
- obesity
- exposure to allergens
- infections (viral)
- occupational exposures
- tobacco smoke, air pollution
- diet
What is the final common pathway to symptoms and physiologic change in asthma?
Airway narrowing. Roughly understand the chart below
Asthma is intermittent. What does this mean?
PFTs are completely normal between exacerbations
True or False: there is reversibility of airflow obstruction in asthma
true
What 5 things can exacerbate asthma?
- exercise
- cold air
- allergens
- air pollution
- infection
What happens to DLCO in asthma patients?
DLCO is normal or increased
How can you tell the difference between asthma and vocal cord dysfunction?
Asthma presents with expiratory wheezing while vocal cord dysfunction presents with inspiratory stridor.
How can bronchoprovocation detect occult asthma (or exclude the diagnosis)?
You give methacholine from a low dose to see if they have a drop in FEV1 (at least 20 percent change) before hitting 8 mg/ml.
What happens with acute asthma?
- Hyperinflation
- Decrease in tension and pressure generated by shortened and flattened diaphragm muscle
- Breathing occurs on the flatter part of the PV curve, more pressure is required to get a small change in volume
- accessory muscle use
- increased work for breathing
What does the P-V curve look like for acute asthma?
What are the classes of asthma severity and what symptoms go along with each?