Partial 6 - COPD

Question 1

Which part of airways is affected in asthma, chronic bronchitic and emphysema

Answer 1

Asthma - Large bronchi
Chronic bronchitis - Small bronchi
Emphysema - Alveoli

Question 2

Risk factors for COPD

Answer 2

1) Exposures; Passive smoking, Ambient air pollution (SO2, NO2), Occupational dust/chemicals, Smoking, socioeconomic status, and childhood infections (PAOSSC)
(2) Host factors; α1-antitrypsin deficiency, hyperresponsive airways, and lung growth.

Question 3

Effects of smoking (Oxidative stress)

Answer 3

(1) Oxidative stress; Cigarettes contain a lot of oxidants (O2-, OH-, H2O2, HOCl). Fe2+ catalysed production of OH- by neutrophils, eosinophils and alveolar macrophages. Cigarettes contains NO which can react with oxygen and O2- and be converted to nitrates and nitrites including peroxynitrite (O=NOO-) which is a reactive oxygen species.

Question 4

Effects of smoking (Elastin breakdown)

Answer 4

(2) Elastin breakdown; Activated neutrophils release elastases and oxidants. α1-antitrypsin and metalloproteinase inhibitors (lung defenses) inactivated by smoke. Patients that have deficiency will loose these defences and degradation of elastin decreases elasticity and increases lung compliance

Question 5

Smoking leads to

Answer 5

• Proinflammatory state with increased expression of pro-inflammatory mediators (IL-8, NF-kB)
• Increased levels of myeloperoxidase and eosinophilic cationic protein leading to bronchoconstriction
• Increased levels of TGF-β which leads to fibrogenesis
• Lipid peroxidation and DNA damage, which lead to epithelial dysplasia and lung cancer.
• Decreased ciliary function, retained secretions, increased airway resistance, and vagal mediated smooth muscle contraction.
• Hypertrophy and hyperplasia of mucus secreting glands and thus increased secretions.

Question 6

Which pathologies are absent in COPD

Answer 6

Basement membrane thickening
Smooth muscle hypertrophy
Epithelial damage

Question 7

Which pathologies are absent in Asthma

Answer 7

Alveolar destruction

Question 8

Physical signs of COPD

Answer 8

(1) Ronchi, which in early disease are present on forced expiration, but later it is present in inspiration and expiration
(2) Prolonged forced expiratory time (>6 sec)
(3) Hyperinflation; With decreased cardiac dullness, liver dullness displaced downward, increased AP chest diameter, decreased heart and breath sounds, Hoover sign (inward movement of the lower rib cage during inspiration
(4) Inspiratory crepitations (lung bases)
(5) Pursed lips breathing (decreases dynamic airway collapse)
(6) Use of accessory respiratory muscles
(7) Signs of cor pulmonale and PHT.

Question 9

Predominant inflammatory cells in asthma

Answer 9

CD4+ T lymphocytes
Eosinophils
Mast cells

Question 10

Predominant inflammatory cells in COPD

Answer 10

CD8+ T lymohocytes
Neutrophils
Macrophages

Question 11

Similarities in COPD and Asthma

Answer 11

(1) Bronchial hyperreactivity
(2) Bronchodilator response
(3) Peripheral blood eosinophilia
(4) Elevated IgE
(5) Eosinophils in the BAL (bronchoscopic alveolar lavage) and airways.

Question 12

Spirometric classification of COPD

Answer 12

FEV1/FVC ratio < 70%

FEV1 < 80%

Question 13

Complications of COPD

Answer 13

Hypoxemia, cor pulmonale, hypercapnia and dyspnea

Question 14

Chronic bronchitis subdivisions

Answer 14

Simple chronic bronchitis
Chronic mucopurulent bronchitis
Chronic bronchitis with obstruction
Chronic bronchitis with obstruction and airway hyperreactivity

Question 15

Emphysema subdivisions

Answer 15

Centriacinar (centrilobular) where central parts of acini is affected

Panacinar, where the central and peripheral portions of acinus is affected

Paraseptal (distal acinar), where there is distention of alveolar spaces adjacent to septal and pleural surfaces,

Senile emphysema, characterized by enlargement of alveoli and alveolar ducts.

Question 16

Which lobes are effected in the different types of emphysema

Answer 16

In Centriacinar emphysema the upper lobes are most severely affected and this type of emphysema is strongly associated with smoking.

In Panacinar emphysema the lower lobes are more severely affected and this type is strongly associated with α1-antitrypsin deficiency.

Question 17

Physiologic differences in asthma and COPD

Answer 17

Asthma:

• Normal DLCO (CO diffusing capacity)
• Normal lung volume
• Normal elastic recoil
• Flow dominant BD response (bronchodilator)

COPD:

• Abnormal DLCO
• Hyperinflation
• Decreased elastic recoil
• Volume dominant BD response

Question 18

Emphysema and Chronic bronchitis major differences

Answer 18

• Emphysema = Pink puffer and Chronic bronchitis = Blue bloater
• Chronic bronchitis does not have rest dyspnea
• Chronic bronchitis has a prominent cough
• Chronic bronchitis has large and purulent sputum while emphysema has scanty and mucoid
• Chronic bronchitis often involve respiratory infection
• Chronic bronchitis often manifests cor pulmonale
• Chronic bronchitis has mild-moderate PHT at rest
• Emphysema use accessory muscles of respiration
• Chronic bronchitis include sleep apnea
• Emphysema shows hyperinflation on chest X-ray
• Emphysema has decreased elastic recoil