Chronic Pulmonary Infection (DISEASE MECHANISMS)

Question 1

What are the risk factors for developing chronic pulmonary infections?

Answer 1

Abnormal host response / innate host defence

Repeated insult

Question 2

In which ways can innate host defects be abnormal increasing risk for developing chronic pulmonary infections?

Answer 2

Damaged bronchial mucosa
Abnormal cilia
Abnormal secretions

Question 3

What are the two types of immunodeficiency?

Answer 3

Congenital

Acquired

Question 4

What are the origins of immunosuppression?

Answer 4

Drugs

Malignancy

Question 5

What are examples of repeated insult that can increase risk for chronic pulmonary infections?

Answer 5

Aspiration

Indwelling material

Question 6

What are the four types of immunodeficiency?

Answer 6

Antibody deficiencies
Hypo-Splenism
Immune paresis
HIV

Question 7

What does a deficiency in IgA cause? Is it common/rare?

Answer 7

Common

Increased risk of acute (rarely chronic) infections

Question 8

What does hypogammaglobulinaemia cause? Is it common?

Answer 8

Rare

Increase risk of acute & chronic infections

Question 9

What does CVID cause? is it common?

Answer 9

Most common cause of immunodeficiency

Causes recurrent infections

Question 10

What is specific polysaccharide deficiency?

Answer 10

Inability to make antibodies against polysaccharides

Question 11

Without a spleen you can’t produce ____ so you need _______________

Answer 11

antibodies

lifelong prophylactic penicillin therapy

Question 12

What is immune paresis?

Answer 12

Can only produce 1 type of antibody that is typically non-functional and stops secretions of other antibodies

Question 13

Which therapies cause immunosuppression?

Answer 13

Steroids
Azathioprine 
Methotrexate
Cyclophosphamide
Monoclonal antibodies 
Chemotherapy

Question 14

What can damage the bronchial mucosa`

Answer 14

Smoking
Recent pneumonia
Viral infection
Malignancy

Question 15

What cause cause abnormal cilia (congenital)?

Answer 15

Kartenager’s syndrome

Young’s Syndrome

Question 16

What can cause abnormal secretions?

Answer 16

Cystic fibrosis

Channelopathies

Question 17

What can cause recurrent aspiration?

Answer 17

NG feeding
Poor swallow
Pharyngeal pouch

Question 18

What can cause indwelling material?

Answer 18

NG tube in the wrong place
Chest drain
Inhaled foreign body

Question 19

What are the forms of chronic infection?

Answer 19

Intrapulmonary abscess
Empyema
Chronic bronchial sepsis
Bronchiectasis
CF 
Others

Question 20

How does a patient with an intrapulmonary abscess present?

Answer 20

Indolent
Weight loss commonLethargy, tiredness, weakness
Cough +/- sputum
High mortality if untreated (death by sepsis)
Usually preceding illness

Question 21

Which illnesses precede intrapulmonary abscesses?

Answer 21

Pneumonia
Aspiration pneumonia
Poor host immune response (Hypogammaglobulinaemia)

Question 22

What is the course of treatment if an abscess is too large for antibiotics to reach it?

Answer 22

‘Pop’ the abscess then give antibiotics

Question 23

Which pathogens cause intrapulmonary abscesses?

Answer 23

Bacteria (streptococcus / staphylococcus)
E-coli
Gram negs
Fungi (Aspergillus)

Question 24

How are multiple abscesses formed?

Answer 24

Bacteria enter blood > lungs act as filter > filter out clots & bacteria -causes-> seeding of bacteria throughout lung

Question 25

What is empyema?

Answer 25

Pus in the pleural space

Question 26

Patients with empyema have a ___ mortality

Answer 26

high

Question 27

How does a simple parapneumonic effusion progress to empyema?

Answer 27

pH and glucose decrease below 2.2 and LDH rises above LDH to form complicated parapneumonic effusion and then empyema

Question 28

Most of the bacteria that cause empyema are _____

Answer 28

aerobes

Question 29

Which aerobic gram positive bacteria cause empyema?

Answer 29

Staph Milleri | Staph Aureus

Question 30

Which aerobic gram negative bacteria cause empyema?

Answer 30

E-coli Pseudomonas Haemophilus Influenza Kelbsiellae

Question 31

Anaerobic bacteria caused empyema is usually only seen in ____ _______ or _____ _____ ______

Answer 31

severe pneumonia | poor dental hygiene

Question 32

How is an empyema diagnosed?

Answer 32

Clinical suspicion (slow-resolving pneumonia / lateral chest film) CXR - persisting effusion, loculations? USS - targeted sampling CT - differentiate empyema & abscess

Question 33

How is an empyema treated?

Answer 33

USS or CT guided drain | IV (amoxicillin or metronidazole initially) oral antibiotics

Question 34

What is bronchiectasis?

Answer 34

Localised irreversible dilation of the bronchial tree

Question 35

What happens in bronchiectasis?

Answer 35

Involved bronchi are dilated, inflamed and easily collapsible causing airflow obstruction and impaired clearance of secretions

Question 36

How does bronchiectasis present?

Answer 36

Recurrent chest infections No or short-lived response to antibiotics Persistent sputum production

Question 37

What is meant by a signet ring? (referring to radiology)

Answer 37

Large bronchiole with a small artery

Question 38

How do you diagnose bronchiectasis?

Answer 38

Clinical - cough + sputum Chest pain Recurrent LRTs Radiological - HRCT - bronchioles > 1 cm wide

Question 39

What is the pathophysiology of bronchiectasis?

Answer 39

``` Bronchial obstruction Cystic fibrosis Young's syndrome kartaneger's syndrome ABPA Immunodeficiency RA Bronchopulmonary sequestration Mounier-Khun syndrome Yellow nail syndrome Traction bronchiectasis associated with pulmonary fibrosis Alpha-1 antitrypsin deficiency > 50% IDIOPATHIC ```

Question 40

How does chronic bronchial sepsis present?

Answer 40

All bronchiectasis hallmarks / no bronchiectasis on HRCT / confirmed pos. sputum results / often young (mainly female) patients often involved in child care / others older usually with COPD or airways disease

Question 41

How can chronic bronchial sepsis be treated ?

Answer 41

Stop smoking Flu vaccine Pneumococcal vaccine Reactive antibiotic - most appropriate to most recent sputum sample

Question 42

How can chronic bronchial sepsis be treated when colonised with persistent bacteria?

Answer 42

Prophylactic antibiotic Nebuliser gentamicin/colomycin Pulse iv abs Alternating oral antibiotic

Question 43

What anti-inflammatory treatment is there for chronic bronchial sepsis?

Answer 43

Low dose-macrolide reduce exacerbation rates in bronchiectasis Clarithromycin Erythromycin