#19 - Obstructive lung disease Flashcards
Risk factors for asthma
kids
women
blacks
T/F Mortality is increasing for COPD and asthma
false. Mortality is increasing for COPD, but decreasing for asthma.
Prevalence for both is rising.
What causes fatal asthma?
Mucus plugs. Therapy tries to prevent mucus formation.
define chronic bronchitis
clinical diagnosis; presence of a chronic productive cough for 3 months in 2 consecutive years (other causes excluded)
define emphysema
pathological term, describing the abnormal permanent enlargement of airspaces distal to the terminal bronchioles, accompanied by destruction of their walls without “obvious fibrosis”
pathologic features of asthma
- goblet cell hyperplasia
- mucus gland hypertrophy
- increased blood vessel numbers
- smooth muscle hyperplasia
- reduced airway lumen area
- subepithelial fibrosis
*note: these factors may all be present in COPD as well
What causes wheezing and “air trapping”?
reduced airway lumen area.
T/F:
Asthma involves the airway and the parenchyma, whereas COPD only involves the airway.
False.
COPD involves the airway and the parenchyma (emphysema affects the alveoli), whereas asthma only involves the airway
What is the most important cell for causing asthma?
eosinophils.
Inflammatory overdrive causes which 4 things in asthma?
- bronchoconstriction
- microvascular leak (edema–>shrinkage of airway)
- mucus secretion (shrinkage of airway)
- airway hyper-responsiveness (infections much worse)
T/F:
In asthma, once remodeling of the airway happens, changes are permanent and irreversible..
True. However, remember that asthma is primarily a reversible illness. Most of the time it does not progress to remodeling
T/F:
Remodeling only occurs in severe cases of asthma.
False. It occurs in “mild” cases (only have symptoms 2/week or 2/month)
What lymphocyte type mediates inflammation in asthma?
CD4 T cells
-eosinophils
What lymphocyte type mediates inflammation in COPD?
CD8 T cells, along with macrophages and neutrophils.
T/F - In asthma, airflow limitation is generally completely reversible; in COPD, it is irreversible
True.
Other risk factors for COPD (besides smoking)
- noxious gases
- ambient pollution
- chronic respiratory infections.
Occupational history is very important!!
T/F: COPD is not just a lung disease; it has many systemic effects.
True. Among them: osteoporosis, sleep disorders, venous thromboembolic disase, hormonal abnormalities.
Important question to ask about coughing in asthma.
Does it occur at night? airways smaller at night (circadian rhythm) - night time symptoms also helps categorize the severity of disease.
T/F: Exercise - induced asthma occurs primarily during exercise.
False - it occurs AFTER exercise, NOT during.
A patient with GERD might have associated asthma. What symptom would probably be present?
night time symptoms.
Physical exam for asthma
-Physical exam of the chest may be normal, due to episodic nature of symptoms.
- wheezing/ prolonged expiration
- hyper-resonance, diminished breath sounds (due to hyperinflation of the lungs. )
-mucosal swelling and polyps in nasal cavity.
What is the major differentiating factor for labs between COPD and asthma?
DLCO = diffusion capacity. basically a measure of how many functional alveolar units. Since asthma doesn’t affect the parenchyma, it is normal or increased, whereas in COPD it is reduced.
Note: reaction to bronchodilator is also important.
Describe the methacholine challenge test for diagnosis of asthma. What is a positive result?
you give progressively stronger doses of methacholine, measuring the FEV1 after every dose. If it drops more than 20% after the 5th dose (or earlier) that is consistent with asthma. Exclude asthma if this test is completely negative (quite sensitive test)
What is a good test if you suspect occupational asthma?
Peak flow variation - they can measure peak flow at work and at home. If it varies more than 20%, this is reactive airway disease
