B4.057 Obstructive Lung Disease

Question 1

what are obstructive airway diseases

Answer 1

increased resistance to airflow due to partial or complete obstruction at any level
decreased maximal airflow rates during forced expiration (FEV1)

Question 2

restrictive lung diseases

Answer 2

not airway disease
reduced expansion of lung parenchyma
decreased total lung capacity/volume
decreased compliance

Question 3

emphysema

Answer 3

abnormal permanent enlargement of the airspaces distal to the terminal bronchiole
destruction of walls without obvious fibrosis
small airway (bronchiole) fibrosis

Question 4

epidemiology of emphysema

Answer 4

male predominance
smoking major cause
gradual development, symptoms seen at age 40+

Question 5

when does emphysema manifest?

Answer 5

once 1/3 of the functioning lung parenchyma is impaired

Question 6

2 primary emphysema types

Answer 6

centriacinar

panacinar

Question 7

2 secondary emphysema types

Answer 7

distal acinar/paraseptal

irregular

Question 8

centriacinar emphysema

Answer 8

central/proximal portions of acini (resp bronchioles) affected, but distal alveoli are spared
more common in upper lobes

Question 9

most common type of emphysema

Answer 9

centriacinar

>95% of cases

Question 10

panacinar emphysema

Answer 10

acini are uniformly enlarged from respiratory bronchiole to the alveoli
worst at bases of lungs

Question 11

which type of emphysema is seen with alpha 1 antitrypsin deficiency

Answer 11

panacinar

Question 12

distal acinar emphysema

Answer 12

distal acinus is predominantly involved
adjacent to pleura, along the septa
next to fibrosis, scarring, or atelectasis
worse in upper lungs

Question 13

which type of emphysema predisposes to pneumothorax

Answer 13

distal acinar/ paraseptal

bullae near pleura is the issue

Question 14

irregular emphysema

Answer 14

occurs in small foci

clinically insignificant

Question 15

gross pathology of centriacinar vs panacinar emphysema

Answer 15

centriacinar has a mix of dilated and normal air spaces

panacinar is uniformly dilated

Question 16

pathogenesis of emphysema

Answer 16

smoking/genetic predisposposition/ A1AT deficiency initiate cascade
lungs experience:
-oxidative stress, increased apoptosis and senescence
-inflammatory cells and release of inflammatory mediators
-protease/antiprotease imbalance
all result in alveolar wall destruction

Question 17

what enzymes contribute to tissue damage in emphysema

Answer 17

proteases
neutrophil elastases
macrophage elastase
metalloproteinases

Question 18

prevalence of A1AT def

Answer 18

1% of emphysema patients
100,000 americans
predisposed to liver disease

Question 19

what finding might you see on histo of emphysema in addition to dilated air spaces

Answer 19

ruptured alveolar septae due to breakdown by proteases etc.

Question 20

mechanism of emphysema

Answer 20

functional airflow obstruction
normally small airways are tethered open by the elastic recoil in the walls of surrounding alveoli
loss of elastic tissue in alveolar walls allows the resp bronchioles to collapse during expiration

Question 21

chronic bronchitis definition

Answer 21

productive cough of unknown cause occurring for 3 or more months in at least 2 successive years
chronic irreversible obstruction of airflow

Question 22

chronic bronchitis epidemiology

Answer 22

all people, all ages
longtime smokers, polluted urban areas
more common > 45
more common in men

Question 23

pathogenesis of chronic bronchitis

Answer 23

initiating factor: exposure to noxious inhaled substances
mucus hypersecretion in airways (IL-13)
metaplasia/hypertrophy/remodeling of small airways
inflammation
infection (maintains disease process and causes acute exacerbations)

Question 24

pathogenesis of chronic bronchitis in the context of smoking

Answer 24

1. injures airway epithelium > chronic inflammation

2. impairs ciliary action of airway epithelium > mucus > infection

Question 25

histo findings in chronic bronchitis

Answer 25

goblet cell metaplasia of bronchial epithelium increased size of mucus glands (thickness > 40% of bronchial wall) mucus plugs lymphocytes in bronchiolar wall

Question 26

anatomic compartment affected by chronic bronchitis

Answer 26

bronchus

Question 27

characteristics of a patient w predominant bronchitis

Answer 27

``` 40-45 mild dyspnea copious sputum rhonchi common infections repeated resp insufficiency cor pulmonale common increased airway resistance normal elastic recoil no weight loss ```

Question 28

CXR findings in chronic bronchitis

Answer 28

prominent vessels large heart cor pulmonale

Question 29

characteristics of a patient w predominant emphysema

Answer 29

``` 50-75 severe dyspnea scant sputum prominent weight loss diminished breath sounds occasional infections terminal resp insufficiency/ cor pulmonale normal airway resistance low elastic recoil ```

Question 30

CXR findings in emphysema

Answer 30

hyperinflation, small heart

Question 31

complications of COPD

Answer 31

pulm hypertension leading to cor pulmonale (R heart failure) pneumothorax with massive lung collapse (emph) superimposed infections (bronch)

Question 32

asthma definition

Answer 32

chronic disorder of the conducting airways, usually caused by an immunological reaction episodic bronchoconstriction due to increased airway sensitivity to a variety of stimuli inflammation of bronchial walls increased mucus secretion

Question 33

symptoms of asthma

Answer 33

recurrent episodes of wheezing, breathlessness, chest tightness, cough particularly at night or in the early morning usually reversible, either spontaneously or with treatment

Question 34

epidemiology of asthma

Answer 34

5% of pop any age most common in kids, decreases at puberty, increases with age increasing incidence

Question 35

continuous asthma symptoms

Answer 35

status asthmaticus | can be fatal

Question 36

atopic asthma

Answer 36

evidence of allergen sensitization and immune activation | often with allergic rhinitis or eczema

Question 37

non atopic asthma

Answer 37

no evidence of allergen sensitization

Question 38

triggers of asthma

Answer 38

``` seasonal exercise drugs occupational asthmatic bronchitis in smokers ```

Question 39

characterize atopic asthma

Answer 39

``` most common type begins in childhood antigen is implicated positive fam history allergic rhinitis, urticarial, or eczema ```

Question 40

atopic asthma testing findings

Answer 40

IgE mediated type 1 hypersens high serum levels of IgE RAST detects presence of IgE for specific allergens skin test wheal and flare reactions

Question 41

pathogenesis of atopic asthma

Answer 41

complex and multifactorial TH2 and IgE response to environmental allergens in genetically predisposed individuals fundamental abnormality is an exaggerated TH2 response to normally harmless environmental antigens

Question 42

susceptibility locus for asthma

Answer 42

chromosome 5q | encodes interleukins; IL-13

Question 43

environmental factors for asthma development

Answer 43

airborne pollutants hygiene hypothesis young children with aeroallergen sensitization and lower resp tract viral infections have a 10-30x risk of developing asthma

Question 44

drug induced asthma

Answer 44

several drugs can provoke

Question 45

aspirin induced asthma

Answer 45

+ recurrent rhinitis, nasal polyps small doses of NSAIDs provoke asthmatic attacks and urticarial inhibits COX pathway of AA metabolism > decrease PGE2 release inhibition of enzymes that generate pro inflamm mediators (LTB4,C4,D4,E4)

Question 46

histo findings with asthma

Answer 46

mucus plugs curschmann spiral - coiled fragment of inspissated mucus eosinophils Charcot Leyden crystals from eosinophil breakdown

Question 47

airway remodeling seen in asthma

Answer 47

thickening of airway wall sub BM fibrosis increased vascularity and macrophages in lamina propria increased size of submucosal glands and number of airway goblet cells hypertrophy/hyperplasia of muscle

Question 48

what is bronchiectasis

Answer 48

destruction of airway muscle and elastic tissue, resulting in permanent dilation of bronchi and bronchioles often due to chronic necrotizing infections

Question 49

clinical features of bronchiectasis

Answer 49

cough (copious, foul smelling, purulent sputum) hemoptysis recurrent acute infective exacerbations can lead to severe lung function impairment dyspnea and wheezing

Question 50

primary causes of bronchiectasis

Answer 50

``` idiopathic (30-53%) postinfectious (29-42%) congenital or hereditary bronchial obstruction other ```

Question 51

pathogenesis of bronchiectasis

Answer 51

1. bronchial obstruction > normal clearing mechanisms are impaired > pooling of secretions distal to obstruction > secondary infection and inflammation 2. severe infections > inflammation, necrosis, fibrosis, airway dilation both paths lead to destruction of bronchiole wall

Question 52

how does bronchiectasis arise in CF

Answer 52

inherited defect in ion transport impairs mucociliary action and creates airway obstruction by thick viscous secretions predisposes to chronic bacterial infections > extensive airway damage > destruction of SM and elastic tissue

Question 53

result of bronchiectasis in CF

Answer 53

markedly dilated bronchi and fibrotic obliteration of smaller bronchioles

Question 54

what is primary ciliary dyskinesia

Answer 54

autosomal recessive syndrome defect in ciliary motor protein (dynein) ciliary function is necessary for proper rotation of organs during development and for bacterial clearance in the sinus and airways poorly functioning cilia lead to retention of secretions and recurrent infections

Question 55

what is Kartagener's Syndrome

Answer 55

50% of people w primary ciliary dyskinesia have it situs inversus bronchiectasis sinusitis

Question 56

complications of bronchiectasis

Answer 56

cor pulmonale amyloidosis metastatic brain abscesses

Question 57

management of bronchiectasis

Answer 57

treatment of underlying cause chest physical therapy to facilitate airway clearance antibiotic therapy

Question 58

histo findings with bronchiectasis

Answer 58

necrotizing inflammation of bronchi and bronchioles fibrosis atelectasis and intraluminal secretions