MIDTERM Resp Illnesses Flashcards
How is chronic bronchitis defined?
Hypersecretion of mucus and chronic productive cough for at least 3 months of the year (usu winter months) for at least 2 yrs
WHat physical changes are occurring in the airways in chronic bronchitis? What causes the cascade of issues?
Inspired irritants cause airway inflammation
Infiltration of neutrophils, macrophages, and lymphocytes into the bronchial wall
Continual bronchial inflammation ->
1) bronchial edema
2) increase in size & # of mucus glands and goblet cells in airway epithelium
3) smooth muscle hypertrophy w/fibrosis
4) narrowing of airways
- thick tenacious mucus
Why is someone with chronic bronchitis more prone to infection?
Lung’s defence mechanisms are impaired -> more prone to infection, injury, and ineffective repair
Frequent infectious exacerbations from bacterial colonization of damaged airways plus bronchospasm, dyspnea, productive cough
Is inspiration or expiration particularly affected in chronic bronchitis? WHy?
Expiration
Thick mucus + hypertrophied bronchial smooth muscle -> constriction of airways -> obstruction of airways, especially during expiration when airways are narrowed
Airway collapse happens early in expiration, trapping gas in the distal portions of the lung (hyperinflation)
Air trapping -> decreased TV, hypoventilation, hypercapnia
Are the pathological changes in chronic bronchitis reversible?
No but can prevent progression (smoking cessation)
Differentiate chronic bronchitis and emphysema with regard to characteristic airway changes
CB: bronchial edema, hypersecretion of mucus, bacterial colonization of airways
Emphysema: destruction of alveolar septa and loss of elastic recoil from bronchial walls
***Obstruction from changes in lung tissues rather than mucus production and inflammation as in chronic bronchitis.
Is the following symptom common in CB or emphysema:
CHRONIC PRODUCTIVE COUGH
Classic in CB
Only with infection in Emphysema
Is the following symptom common in CB or emphysema: DYSPNEA
CB: late in course
E: common
Is the following symptom common in CB or emphysema: WHEEZING
CB: intermittent
E: common
Is the following symptom common in CB or emphysema: BARREL CHEST
CB: occassionally
E: CLASSIC
Is the following symptom common in CB or emphysema: Prolonged expiration
Always present in both!
Is the following symptom common in CB or emphysema: CYANOSIS
CB: common
E: uncommon
Is the following symptom common in CB or emphysema: CHRONIC HYPOVENTILATION
CB: common
E: late in course
Is the following symptom common in CB or emphysema: POLYCYTHEMIA
CB: common
E: late in course
Is the following symptom common in CB or emphysema: COR PULMONALE
CB: common
E: late in course
What is Cor Pulmonale?
abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels.
Means “pulmonary heart”
What is the key characteristic of changes in emphysema?
Abnormal permanent enlargement of gas-exchange airways (acini) accompanied by destruction of alveolar walls without obvious fibrosis.
Major mechanism of airflow limitations is loss of elastic recoil.
WHat causes PRIMARY emphysema?
d/t inheritable α1-antitrypsin. Usu for ppl who develop emphysema before age 40 and do not smoke.
Patho of emphysema
Breakdown of elastin within septa in alveoli from imbalance of proteases and apoptosis of lung structural cells -> destruction of alveoli
This causes large air spaces within the lung parenchyma (bullae) and air spaces adjacent to pleurae (blebs) -> not effective at gas exchange
Expiration is difficult d/t loss of elastic recoil. Reduction of air that can be expired passively and air trapping occur
Air trapping -> hyperexpansion of chest -> increases workload of breathing
Later on, hypoventilation and hypercapnia
Persistent inflammation in the airways can result in hyper-reactivity of bronchi w/bronchoconstriction
Chronic inflammation -> weight loss, muscle weakness, increased susceptibility to comorbilities (I.e. infection)
Destruction of alveolar walls & pulm capillaries leads to what complications in emphysema?
Pulm Art Hypertension and cor pulmonale
A marked decrease in FEV1 means what?
obstruction to gas flow during expiration
What are the 3 obstructive lung diseases?
Asthma, chronic bronchitis & emphysema
When does allergic asthma vs non-allergic asthma present over lifespan?
incidence of allergic asthma is higher in childhood, incidence of non-allergic asthma usually occur after age 40.
RIsk factors for asthma?
age at onset of disease, levels of allergen exposure, urban residence, exposure to air pollution, tobacco smoke, recurrent viral resp infections, GERD, obesity
T/F there is a genetic component to risk of getting asthma
Yes
more than 100 genes identified that play a role in susceptibility, pathogenesis, and treatment respons
Is all asthma similar?
No, many different phenotypes