Pathology of pulmonary infection

Question 1

List some upper respiratory tract infections

Answer 1

Coryza - common cold
Sore throat syndrome
Acute laryngotracheobronchitis (croup)
Laryngitis
Sinusitis
Acute epiglottitis

Question 2

What infections usually cause acute epiglottis?

Answer 2

Group A beta-haemolytic streptococci
Haemophilus influenza type B
Parainfluenza type 4

Question 3

List some lower respiratory tract infections

Answer 3

Bronchitis
Bronchiolitis
Pneumonia

Question 4

Describe some respiratory tract defence mechanisms

Answer 4

Macrophage-mucociliary escalator system
Immune system
Respiratory tract secretions

Question 5

What are the 7 different types of pneumonia

Answer 5

Community acquired pneumonia
Hospital acquired/nosocomial pneumonia
Pneumonia in the immunocompromised
Atypical pneumonia
Aspiration pneumonia
Recurrent pneumonia
Cryptogenic organising pneumonia/bronchiolitis obliterates organising pneumonia (COP/BOOP)

Question 6

What are some complications of pneumonia?

Answer 6

Pleurisy
Pleural effusion
Empyema
Fibrosis from chronic inflammation
Lung abscess
Bronchioectasis

Question 7

Describe COP/BOOP

Answer 7

Non-infectious pneumonia, inflammation of bronchioles and surrounding tissue, which is often complicated with an existing chronic inflammatory disease or induced by certain drugs (amiodarone)

Question 8

What drug can cause COP/BOOP?

Answer 8

Amiodarone

Question 9

What can cause a lung abscess?

Answer 9

Obstructed bronchus
Aspiration
Certain organisms e.g. SA, pneumococci
Pyaemia
Necrotic lung

Question 10

What can cause bronchiectasis?

Answer 10

Severe infective episodes
recurrent infections
proximal bronchial obstruction
lung parenchymal destruction
Damage to epithelium/cilia e.g. viral infections

Question 11

Describe bronchioectasis

Answer 11

Bronchi dilates, making the MCE not as effective. Debris collects and infections develop

Question 12

What are the common symptoms of bronchiectasis?

Answer 12

Cough
Abundant purulent foul smelling sputum
Haemoptysis
Signs of chronic infection
Coarse crackles
Clubbing

Question 13

How do you treat bronchiectasis?

Answer 13

Postural drainage
Antibiotics
Surgery in severe cases

Question 14

What can cause recurrent lung infections?

Answer 14

Bronchial obstruction - tumour, foreign body
Pulmonary damage - bronchiectasis
Lung disease - CF, COPD
Non-resp disease - immunocompromised

Question 15

What can cause aspiration pneumonia?

Answer 15

Vomiting
Oesophageal lesion
Obstetric anaesthesia
Neuromuscular disorders
Sedation

Question 16

List some opportunistic pathogens which can cause pneumonia

Answer 16

Low grade bacterial pathogens
CMV
Pneumocystis jirovecii
Fungi/yeasts

Question 17

Describe type I respiratory failure

Answer 17

Low PaO2 and normal/low PaCO2
Lung damage
V-P mismatch or R to L shunts

Question 18

Describe type II respiratory failure

Answer 18

Low PaO2 and high PaCO2

Alveolar hypoventilation

Question 19

What can cause type I respiratory failure?

Answer 19

Low ambient oxygen
V-P mismatch
Alveolar hypoventilation
Diffusion problems
Shunt

Question 20

What causes type II respiratory failure?

Answer 20

Increased airways resistance
Reduced breathing effort
Decrease in lung area available for GE
Neuromuscular problems
Deformed/rigid/flail chest

Question 21

What 4 abnormal states are associated with hypoxaemia (can think of these for each specific lung disease)?

Answer 21

V-P mismatch
Diffusion impairment
Alveolar hypoventilation
Shunt

Question 22

How can pulmonary vascular changes in hypoxaemia affect the heart?

Answer 22

In long standing hypoxia, if all the vessels to the heart are constricted in response to poor ventilation, the right ventricle adapts and hypertrophies to try and compensate by increasing blood flow to the lungs = right sided heart failure

Question 23

Describe pulmonary shunt

Answer 23

Blood passes from right to left side of the heart without contacting ventilated alveoli

Question 24

What is hypoxic cor pulmonale?

Answer 24

Hypertrophy of the right ventricle resulting from disease affecting the function and/or structure of the lung