Flashcards in Resp Path 2 - OBSTRUCTIVE DZ, Emphysema, Chronic Bronchitis, Asthma, Bronchiectasis, CF - Galbraith Deck (51)
What is obstructive lung disease?
Resistance to airflow from trachea to alveoli.
Forced expiration: FEV/FVC
Together, emphysema and chronic bronchitis form....
What demographic is most susceptible to COPD?
What environmental factor has a strong association?
- Females and African Americans
How is asthma distinguishable from emphysema and chronic bronchitis?
Presence of reversible bronchospasms.
Emphysema is characterized by __1__ of airspaces __2__ to terminal bronchioles.
- irreversible enlargement
Location and demographic of centriacinar emphysema.
- Destruction/enlargement of central or proximal parts of respiratory unit - SPARES DISTAL ALVEOLI.
- UPPER LOBE/APEX involvement.
- Occurs in HEAVY SMOKERS (with chronic bronchitis)
Location and associated deficiency in Panacinar Emphysema.
- Destruction/enlargement of acinus (ALVEOLI).
- Lower basal (BASE of LUNGS) zones involvement.
- Associated with alpha1-antitrypsin deficiency.
Location of distal acinar (paraseptal) emphysema.
What does this often subsequently cause?
- Involves DISTAL ACINUS.
- Near pleura and adjacent to fibrosis or scars.
- Causes spontaneous pneumothorax
What is the pathogenesis of alveolar destruction in emphysema?
Smoking/pollutant and congential a1-antitrypisin deficiency results in 3 imbalances:
1) Imbalances between pulmonary proteases and antiproteases (elastase release).
2) Inflammatory cells
3) Oxidative stress
Define a1-antitrypsin's role in emphysema.
- An antiprotease
- Chromosome 14
- 80% of homozygotes for Z allele (PiZZ) will develop SYMPTOMATIC PANACINAR EMPHYSEMA
alpha1-antitrypsin deficiency, leading to panacinar emphysema
What accelerates and intensifies severity of a person with PiZZ?
Why is emphysema considered an obstructive lung disease?
Destruction of elastic alveolar walls surrounding respiratory bronchioles leads to COLLAPSE of those bronchioles during EXPIRATION - normally held open by elastic recoil of lung parenchyma.
how much lung parenchyma must be loss for symptoms of emphysema to show?
What is this?
A patent presents with weight loss, dyspnea, wheezing, cough, barrel chested/overdistension, prolonged expiration due to OVER VENTILATION.
What may emphysema progress to?
What 4 things are death usually due to?
Pulmonary HTN and right sided HF.
Death: respiratory acidosis/failure, RHF, pneumothorax >> lung collapse.
What is this?
A chronic, persistent productive cough without other identifiable cause. Common in smokers/polluted environments.
What is the pathogenesis of chronic bronchitis?
1. Initiating factor >> exposure of bronchi to inhaled irritants.
2. Mucus hypersecretion
3. Chronic inflammation >> damage and fibrosis of small airways
4. Diminished ciliary action of respiratory epithelium, leading to STASIS OF MUCUS.
What are three other form of emphysema?
1) Compensatory hyperinflation
2) Obstructive overinflation
3) Insterstitial emphysema
What is compensatory hyperinflation
Form of emphysema - LOSS OF ALVEOLI but WITHOUT SEPTAL WALL DESTRUCTION
(dt surgical removal of diseased lung with recoil, allowing alveolar expansion)
What is obstructive overinflation?
Form of emphysema - expansion of lung because of TRAPPED AIR, but WITHOUT SEPTAL WALL DESTRUCTION
subtotal obstruction of an airway, thereby creating a ball-valve that admits air on inspiration but TRAPS it on expiration.
(dt tumor, FBAO, Asthma)
What is interstitial emphysema?
Form of emphysema - alveolar tears, resulting of ENTRY OF AIR INTO CONNECTIVE TISSUE of lung/mediastinum/subQ tissues.
Morphology in chronic bronchitis (5)
1) Edema of lung mucous membranes
2) Mucinous secretions plugging small bronchi and bronchioles (goblet cells)
3) Bronchilar inflammation and fibrosis
4) Mucous gland HYPERPLASIA (*Reid index)
5) bronchial epith SQUAMOUS METAPLASIA and dysplasia.
What is the Reid index
Ratio of mucous glad layer thickness to distance from epithleium to cartilage.
- Normally 0.4
- >0.4 = increased thickness = hyperplasia of mucous glads
What is this?
Persistent, productive cough. Dyspnea on exertion. Classically: Hypercapnic, hypoxia, mild cyanosis.
Chronic Bronchitis, "Blue Bloater"
(hypoxia=trouble moving air in/out)
What does long standing chronic bronchitis often progress to?
Cor pulmonale with HF.
Death can be secondary to infection.
What are two defining characteristics of:
2) Chronic bronchitis
Emph/CB due to chornic injury/small airway dz:
1) Alveolar wall destruction, overinflation.
2) Productive cough, airway inflammation
Asthma due to bronchial hyperresponiveness (triggered by allergen, infection)
3) Reversible obstruction
What is this?
Recurrent wheezing, SOB/chest tightness, cough. More frequent in early AM/late PM.
What are three characteristics of asthma?
1) **RECURRENT BRONCHOCONSTRICTION (unique)
2) Inflammation of bronchial walls
3) Increased mucucs secretion