Chapter 4

Question 1

What are the 3 normal defences of the lung?

Answer 1

1. Large microbes trapped in nose and upper respiratory tract by mucus. Transported by ciliary action of respiratory epithelium to back of throat, where swallowed.
2. Cough Reflex
3. Smaller organisms which are inhaled get phagocytosed by alveolar macrophages and if enter bloodstream, incite immune response

Question 2

Upper respiratory tract infection is caused by what usually?

Answer 2

Self limiting viral disease

Question 3

Which is more serious - lower or upper respiratory tract infection

Answer 3

Lower

Question 4

What increases risk of infection?

Answer 4

1. Damage to host defences due to smoking, intubation, previous infection
2. Poor swallowing
3. Reduced cough reflex

Question 5

What is pneumonia?

Answer 5

Infective inflammation and consolidation of the lung (filling of airspaces by inflammatory exudate which renders affected area solid and airless)

Question 6

What are 3 symptoms of pneumonia?

Answer 6

1. Fever
2. Coughing
3. Difficulty Breathing

Question 7

What are three broad categories that pneumonia may be classified into?

Answer 7

1. Pathological
2. Microbiological
3. Clinical

Question 8

How is pneumonia classified via the pathological classification?

Answer 8

Air Space Spread (Typically bacterial)
- Bronchopneumonia
- Lobar Pneumonia

Interstitial Spread (Typically Viral)
- Interstitial Pneumonia

Question 9

How is pneumonia classified via the clinical classification?

Answer 9

Community-Acquired

Hospital-Acquired

Disease Acquired in Special Environments

Disease in Immunosuppressed Patients

Aspiration Pneumonia

Question 10

How is pneumonia classified via the microbiological classification?

Answer 10

By causative organism

Question 11

What is pneumonitis?

Answer 11

Inflammatory disease dominated by interstitial inflammation

Question 12

What causes pneumonitis?

Answer 12

1. Infection
2. Inhaled Toxins and Allergens
3. Drug Reactions
4. Irradiation
5. Connective Tissue Disease

Question 13

What is the appearance of bronchopneumonia?

Answer 13

1. Primary infection centred on bronchi, spreading to involve adjacent alveoli
2. Initially patchy, may become confluent

Question 14

When is bronchopneumonia common?

Answer 14

Infancy and old age

Question 15

Which part of the lung does bronchopneumonia affect more?

Answer 15

Lower Lobes

Question 16

What is the pathogenesis of lobar bronchopneumonia?

Answer 16

Organisms gain entry to distal airspaces rather than colonising bronchi.

Rapid spread through the alveolar spaces and bronchioles lead to whole lobe being affected

Question 17

What organisms tend to cause lobar pneumonia?

Answer 17

S. pneumoniae

Klebsiella

Question 18

What is the worrying aspect about lobar pneumonia?

Answer 18

Often causes severe illness, with bacteraemia

Question 19

What organisms cause Community-acquired pneumonia?

Answer 19

Gram Positive (S. pneumoniae, H. influenza, Legionella, Mycoplasma, M. tuberculosis) or Viral

Question 20

What organisms cause Hospital-acquired pneumonia?

Answer 20

Gram Negative (e.g. Klebsiella, E. Coli Pseudomonas)

May also be caused by organisms that cause CAP but with reduced frequency

Question 21

Which patients are at risk of HAP?

Answer 21

Mechnical Ventilation

Question 22

Why would microbiological investigation of sputum in intubated patients a problem?

Answer 22

Colonisation

Question 23

How to investigate intubated patients?

Answer 23

Sampling of affected lung by bronchoalveolar lavage (BAL)