Sputum and the Airways

Question 1

What are airway defences

Answer 1

Physical mechanisms, airways fluid and mucociliary escalatory, innate and adaptive mechanisms, nasal hair, turbinates and mucociliary transport

Question 2

What are the physical defense mechanisms

Answer 2

Humidification, particle expulsion (cough/ sneeze), and particle removal: 90& 10um particls removed in nostril/ nasopharynx, 1-2um particles deposited in the lung. Turbulent flow leads to impaction of particles and clearance by mucociliary transport then the cough reflex

Question 3

Describe airways fluid

Answer 3

Mucus is gelatinous substance consisting mainly of polysaccharides. Relatively impermeable to water. Secreted from goblet/ mucus glands. Cilia contact with this gel layer and coordinate to push the layer continually upwards (mucociliary escalator)

Question 4

Describe a cilum in cross section

Answer 4

9 outer doblets and 2 central microtubules

Question 5

What are the two aspects of lung immune defense

Answer 5

Innate and adaptive (acquired)

Question 6

Describe the lungs innate immunity

Answer 6

Humoral- lactoferrin, lysozymes, defensins, complement. Cellular- alveolar macrophages, induced neutrophils

Question 7

Describe the lungs adaptive immunity

Answer 7

Humoral- B lympohcytes, plasma cells, immunoglobulin. Cellular- dendritic cells, T lymphocytes

Question 8

What make up innate immunity

Answer 8

Alveloar macrophages and epithelial cells which make up the innate immunity

Question 9

What are dendritic cells part of

Answer 9

The acquired immune system

Question 10

What are dendritic cells

Answer 10

Antigen presenting, they travel into the lymphoid tissue and present the antigen to T cells which triggers the release of TNF alpha and INF-gamma.

Question 11

What do T helper cells stimulate

Answer 11

B cells which results in complement activation

Question 12

What does uncontrolled inflammation lead to

Answer 12

A break in the mucociliary transport system which means you can’t remove mucus and therefore get another infection

Question 13

Describe the inflammation infection cycle

Answer 13

External insult (infectious or toxic) -> ciliary dyskinesia or alterted bronchial dynamics (affected by genetic predisposition)-> ineffective mucus clearance -> chronic or recurrent infection (affected by impaired immune system) -> bronchial wall inflammation and destruction (caused by external insult- infectious or toxic)… cycle repeats

Question 14

Clinical features of bronchiectasis in adults

Answer 14

Cough- in over 90% of adults, daily sputum production present in over 75%, intermittent sputum preset in 20%, unproductive cough in up to 8%). Breathlessness (83% of adults). Haemoptysis (83% of adults cough up blood). Chest pain (30% of adults). Weight loss/ malaise/ low energy.

Question 15

When should I suspect bronchiectasis

Answer 15

Adults with a chronic cough, particularly in the presence of any of the following: daily sputum production, pseudomonas aeruginosa in the sputum, a young age at presentation, a history of symptoms over many years, no history of smoking. Adults thought to have chronic obstructive pulmonary disease, who do not smoke, or who have frequent or prolonged exacerbations. Pseudomonas aeruginosa is everywhere, however it is not anatomically normal if it gets into the lungs

Question 16

What are important common causes of chronic cough which should be considered

Answer 16

Smoking, asthma, chronic obstructive pulmonary disease, drug adverse effects (for example ACE inhibitors), postnasal drip, gastro-oesophageal reflux disease

Question 17

What are less common but serious causes of chronic cough

Answer 17

Lung cancer, pulmonary fibrosis, tuberculosis, foreign body

Question 18

What are the signs of bronchiectasis

Answer 18

Coarse crackles (usually in early inspiration, lower lung fields) present in approximately 70%. Wheeze present in 40%. Large airway rhochi in 44%. Finger clubbing occurs infrequently and weight loss

Question 19

What is the cause of the coarse crackles observed in bronchiectasis

Answer 19

Secretions in the airways moving

Question 20

Describe the use of x-ray in people with bronchiectasis

Answer 20

Chest x-ray in all people suspected of having bronchiectasis. Abnormal in 90% of people with bronchiectasis. Main value of chest x-ray is to exclude other causes of cough such as lung cancer

Question 21

What do tram lines show

Answer 21

Bigger airways filled with mucus

Question 22

Describe the aetiology of cystic fibrosis

Answer 22

Genetic: cystic fibrosis (4%). Post-infective (40%)- this is the most important cause, for example people who had whooping cough as a child. Aspiration (4%). Immune deficiency e.g. CIVD (5%)- common variable immune deficiency means that you have no immune memory. ABPA (7%)- abnormal allergic response to fungi. Ciliary defect: PCD (3%)- cilia don’t neat properly. Connective Tissue Disease: (5%). Idiopathic (32%)

Question 23

When do you always need to screen for cystic fibrosis

Answer 23

When a person under the age of 40 is diagnosed with bronchiectasis

Question 24

What do we try to influence in a person with impaired mucociliary clearance

Answer 24

Obstruction, infection and inflammation by trying to decrease the number of those that a person has.

Question 25

What are the aims of treatment

Answer 25

Improve survival, improve lung function, decrease number of exacerbations, improve symptoms, improve QOL (quality of life)