tutorial 8 - obstructive lung diseases

Question 1

What diseases are grouped together under the term Chronic Obstructive Pulmonary Disease (COPD)?

Answer 1

Emphysema, chronic bronchitis

Question 2

What is emphysema?

Answer 2

Destruction of the airspaces distal to the terminal bronchioles resulting to their irreversible enlargement and damage.

Question 3

What is centracinar emphysema?

Answer 3

Destruction of the respiratory bronchioles with normal distal alveoli

Question 4

What is the gross morphology of a lung with centriacinar emphysema?

Answer 4

Holes in the lung parenchyma representing emphysematous air spaces (dilated respiratory bronchioles)

Question 5

What is the term for deposition of carbon pigment in the lungs due to smoking?

Answer 5

Anthracosis

Question 6

What is the pathogenesis of emphysema?

Answer 6

Cigarette smoking/inhaled pollutants produce oxidants that cause inflammation. Inflammatory cells release proteases that destroy elastic tissue in airspace walls

Question 7

What is bullous emphysema?

Answer 7

When emphysema becomes advanced and several dilated airspaces join together forming large bubbles

Question 8

what are the findings of a chest xray of a patient with emphysema?

Answer 8

flattened diaphragm, hyperinflated chest, decreased bronchovascular lung markings

Question 9

What action do patients with emphysema commonly do to compensate for airways collapse?

Answer 9

Purse their lips when breathing - ‘pink puffers’

Question 10

Why do patients with emphysema develop barrel chests?

Answer 10

Due to air trapping in enlarged spaces in the lungs

Question 11

Why is emphysema an obstructive lung disease?

Answer 11

Because there is obstruction to expiration as the lungs lose their elastic recoil

Question 12

What symptoms must be present, and for how long, for a diagnosis of chronic bronchitis?

Answer 12

persistent productive cough for most days in 3 months over 2 years

Question 13

What is the initiating factor for chronic bronchitis?

Answer 13

Cigarette smoke/inhaled chemicals

Question 14

What is the pathogenesis of chronic bronchitis?

Answer 14

1. smoking causes chronic bronchial inflammation
2. inflammation causes bronchial wall to undergo metaplasia of epithelium, hypertrophy and hyperplasias of mucus secreting glands
3. mucus hyper secretion causes productive cough and airways obstruction.

Question 15

What are the features of a chest xray of a patient with chronic bronchitis?

Answer 15

Prominent vessels, large heart

Question 16

Which type of COPD causes ‘blue bloaters’?

Answer 16

Chronic bronchitis

Question 17

What type of COPD causes ‘pink puffers’?

Answer 17

Emphysema

Question 18

What type of hypersensitivity reaction is involved in an acute asthma exacerbation?

Answer 18

Type 1

Question 19

What is the pathogenesis of atopic/extrinsic asthma?

Answer 19

1. exposure to allergen triggers IgE on mast cells in the airways.
2. mast cells degranulate and release cytokines that recruit eosinophils, increase mucus production and stimulate further IgE production
3. IgE crosslinks leading to degranulation and bronchoconstriction, increased vascular permeability and oedema, mucus production and leukocyte recruitment.
4. In the late phase, eosinophils produce proteins that damage the airway epithelium

Question 20

What are the changes that occur in the airways due to remodelling caused by repeated allergen exposure and asthma exacerbations?

Answer 20

basement membrane thickening, hypertrophy of bronchial smooth muscle, hypertrophy of mucus glands and hyperplasia of goblet cells, damaged epithelium, chronic eosinophil infiltration, air trapping

Question 21

What are the findings on a chest xray of a patient with acute severe asthma?

Answer 21

hyperinflated chest, flattened diaphragm, but preserved lung markings

Question 22

What is bronchiectasis?

Answer 22

Permanent dilation of bronchi and bronchioles due to destruction of their walls

Question 23

What causes bronchiectasis?

Answer 23

Repeated cycles of infection with subsequent destruction of the bronchial smooth muscles and elastic tissue with healing via fibrosis

Question 24

Why do conditions causing bronchial obstruction often lead to bronchiectasis?

Answer 24

Because they predispose chronic or recurrent infections

Question 25

Why do patients with CF often have particularly ‘salty sweat’?

Answer 25

Loss of function of chloride channels in sweat gland ducts inhibits action of adjacent sodium channels, meaning sodium and chloride is not absorbed and the the sweat is salty

Question 26

What are the gross morphological findings of a lung in CF?

Answer 26

dilated bronchi/bronchiectasis, areas of bronchopneumonia,

Question 27

What is Cor polmunale?

Answer 27

Right sides congestive heart failure secondary to increase pressure in the lungs caused by pulmonary disease, e.g. COPD