Resp. Pathology 4 - Obstructive Diseases - SRS Flashcards
What are the big four obstructive pulmonary diseases?
- Emphysema
- Chronic bronchitis
- Asthma
- Bronchiectasis
What is the limited factor in obstructive airway diseases?
What is the FEV1/FVC?
Limited Rate Flow
FEV1/FVC reduced <0.7
What is the main cause of obstruction?
Airway restriction, also loss of elastic recoil
What is limited in restrictive disease?
What is FEV1/FVC?
Limited total lung capacity and residual volume.
FEV1/FVC is roughly normal at ~70%
What are five conditions that lead to restrictive disease?
- Chest wall disorders
- Obesity
- ARDS
- Interstitial fibrosis
- pneumoconioses
Name the following for chronic bronchitis!
- Anatomic site
- major pathologic changes
- etiology
- Signs and symptoms
- Bronchus
- Mucus gland hyperplasia, hypersecretion
- Tobacco smoke and air pollutants
- Cough, sputum production
Name the following for emphysema!
- Anatomic site
- major pathologic changes
- etiology
- Signs and symptoms
- Acinus
- Airspace enlargement, wall destruction
- Tobacco smoke
- Dyspnea
Name the following for chronic Asthma!
- Anatomic site
- major pathologic changes
- etiology
- Signs and symptoms
- Bronchus
- smooth muscle hyperplasia, excess mucus, inflammation
- immunological or undefined causes
- Episodic wheezing, cough, dyspnea
Name the following for broncheictasis!
- Anatomic site
- major pathologic changes
- etiology
- Signs and symptoms
- Bronchus
- airway dilation and scarring
- persistent or severe infections
- cough, purulent sputum, fever
Name the following for small airway disease!
- Anatomic site
- major pathologic changes
- etiology
- Signs and symptoms
- Bronchiole
- Inflammatory scarring/obliteration of bronchioles
- Tobacco smoke, air pollutants, miscellaneous
- cough, dyspnea
What are the four classifications of emphysema?
- Centriacinar/centrilobular (95%)
- Panacinar/panlobular (2-5%)
- distal acinar/paraseptal
- Irregular/paracicatrical
What are the risk factors for centriacinar/centrilobular emphysema?
What parts of the lung are typically affected?
Smoking, smoking smoking, smoking.
Predominantly upper lobes/apices
What are the causes of panacinar/panlobular emphysema?
What portions of the lungs are typically affected?
- Alpha-1 antitrypsin def., smoking
- Predominately lower lobes/anterior
Distal acinar/paraseptal emphysema is associated with previously damaged lung. What is the possible acute injury that this can lead to?
May be bullous and cause spontaneous pneumothorax in young adults
Both images show emphysema… what types?
Left: Centriacinar emphysema - central areas show marked emphysematous damage surrounded by relatively spared alveolar spaces.
Right: Panacinar emphysema - involving the entire pulmonary lobule
This is a histological representation of emphysema, what are the noteable characteristics?
Enlarged airspaces, discontinuous alveolar septae. Per Robbins will also enlarged pores of Kahn.
Emphysema is caused primarily by proteolytic digestion of alveolar walls. What is causing the digestion?
Inflammatory cells, primarily neutrophil secreted elastase
Also macros.
What enzyme inhibits neutrophil secreted elastase normally?
What does a deficiency in this enzyme lead to?
Alpha-1-antitrypsin
Deficiency in this leads to early life emphysema.
What gene is mutated in alpha-1-antitrypsin deficiency?
Pi locus chromasome 14
What are some symptoms and physical presentations associated with emphysema in the clinical setting?
Symptoms: dyspnea, cough, wheezing
Presentation: forward leaning and pursed lips to squeeze air out. Barrel chest. Respiratory acidosis
What are four treatment options for emphysema?
Bronchodilators, steroids, bullectomy, transplant
What are four possible complications of emphysema?
- Respiratory acidosis
- formation of bullae and pneumothorax
- cor pulmonale (rare, seen terminally)
What is shown here?
Bullous emphysema with large subpleural bullae in the upper left
What are the other conditions with “increased air”? (3)
- Compensatory hyperinflation
- Obstructive overinflation
- Interstitial emphysema
What causes compensatory hyperinflation?
Loss of adjacent tissue
What causes obstructive overinflation?
Overexpansion by trapped air
1) Ball valve obstruction by object
2) Collaterals feeding around obstruction, life-threatening
- Alveolar pores of Kohn
- Bronchiloloalveolar canals of Lambert
3)Congenital lobar overinflation from lack of bronchial cartilage
What is the clinical definition of chronic bronchitis?
3 months of productive cough per year for two consecutive years
In chronic bronchitis a patient will have hypersecretion of mucus secondary to stimulation by proteases and IL13, as well as hypertrophy of bronchial submucosal glands, leading to an increased “Reid Index”.
What are the risk factors for chronic bronchitis?
What cell type is markedly increased?
What happens to the small airways?
Smoking
Increased goblet cells
Bronchiolitis obiterans
What are some complications associated with chronic bronchitis?
Superimposed infections d/t mucus obstruction
Dyspnea on exertion and cor pulmonale both common
A pink puffer would have?
Emphysema
A blue bloater would have?
Chronic bronchitis: gas exchange impaired with cyanosis
What is the definition of the Reid index?
What do you know if it is greater than 0.4?
Ratio of thickness of glands to thickness of wall (from epithelium to cartilage)
>0.4 means submucosal gland hyperplasia which goes with bronchitis and asthma
Asthma is a chronic inflammatory disorder of airways that presents with episodic, recurring wheezing/breathlessness/chest tightness and cough that is worst in early morning and night.
What is the key feature of this condition?
What can this evolve into?
Key feature: Reactive airspace disease with episodic partially reversible bronchoconstriction
•Can evolve into acute severe asthma (status asthmaticus) and death
Atopic athsma begins in childhood d/t a genetic tendancy to develop IgE antibodies to inhaled allergens. Mucosal mast cells produce inflammatory mediators, which can induce bronchoconstriction in what ways?
Stimulation of subepithelial vagal receptors - parasympathetic stimulation provokes bronchoconstriction
Bronchial smooth muscle reacts to inflammatory mediators by constricting rather than dilating.
What are two tests for atopic asthma?
- Can do skin allergen testing for confirmation
- RAST (radioallergosorbent test) testing
- Often get positivity for huge number of allergens
- High false positive rates have been reported
What are the other asthma types?
- nonatopic asthma
- drug induced asthma
- exercise induced asthma
- occupational asthma
What is the important drug induced asthma we should know about?
Aspirin classic cause
- Thought to inhibit cyclooxygenase pathway of arachidonic acid
- Does not inhibit lipoxygenase route, favoring leukotriene production
- Leukotrienes favor bronchoconstriction
- Can also cause Type I allergic type reaction
What are the key features of this biopsy that point to a diagnosis of asthma?
- Goblet cell hyperplasia
- subbasement membrane fibrosis
- eosinophilic inflammation
- Muscle hypertrophy
This image was obtained from a patients sputum. The crystals were found to contain galectin-10 (eosinophil lysophospholipase binding protein). What are these crystals called?
What disease are they associated with?
Charcot-Leyden Crystals
Asthma
_**Test question and image**_
What is significant about this image?
What does this indicate?
Curschmann Spiral - formed by accumulation of destroyed/shed epithelial cells
Characteristic of lung diseases including asthma
_** Test Question/Image **_
What is the definition of bronchiectasis?
Permanent dilation of bronchi and bronchioles
Bronchiectasis is caused by tissue destruction secondary to infection, and will present with foul smelling infected mucus that may be bloody. They will complain of dyspnea, othopnea and rarely severe hemoptosis and can lead to cor pulmonale.
What are two other complications that can develop?
What conditions are associated with this? (3 bolded, and several others)
•May develop brain abscesses and amyloidosis
Associated with
- Genetic disorders (cystic fibrosis, primary ciliary dyskinesia*)
- Obstruction (foreign body, tumors, mucus)
- Many Infections
- Chronic inflammatory & auto-immune conditions
- Pulmonary sequestration
- Allergic bronchopulmonary aspergillosis (A. fumigatus)
- Autoimmune disorders and post-transplant rejection or graft vs host ds
What disease process caused this? What is notable about this?
Bronchiectasis: note the large dilated spaces where the bronchi should be
What is going on in this lung?
Bronchiectasis again - note the large dilated spaces filled with mucus.
