Obstructive airway diseases overview

Question 1

What are some examples of obstructive airway syndromes?

Answer 1

Asthma
Chronic bronchitis
Emphysema
Asthma/COPD Overlap Syndrome

Question 2

What is the carina?

Answer 2

The cartilage found at the bifurcation of the trachea

Question 3

How many generations of airways are there in the lungs?

Answer 3

23

Question 4

Which lung generations are found in the acinar zone?

Answer 4

Generations 17-23

Question 5

What are the 2 classes of asthma?

Answer 5

Type II High (Atopic)
Type II Low (Non-atopic)

Question 6

What is meant by Type II in asthma classification?

Answer 6

Th2 cytokines 4, 5 and 13 presence

Question 7

What is the asthma triad?

Answer 7

Reversible airflow obstruction
T2 airway inflammation
Airway hyper-responsiveness

Question 8

How does type II inflammation occur in Type II asthma?

Answer 8

Allergen causes epithelial damage
This causes the release of TSLP
This binds to dendritic cells
This stimulates Th2 and B cells
Th2 releases IL4, 5 and 13
These stimulate eosinophils to release cytokines and leukotrienes
These stimulate mast cells to release histamines and IL4, which causes B cells to release IgE

Question 9

What are some common end-types, suggestive of type II high asthma?

Answer 9

Presence of cytokines IL4, 5 or 13
Blood/sputum eosinophilia
Raised FeNO (Fraction expelled Nitric Oxide)
Raises total or specific IgE

Question 10

What are some associated comorbities of type II high asthma?

Answer 10

Allergic rhinoconjunctivitis
Chronic rhino sinusitis with nasal polyps (CRSwNS)
Atopic dermatitis
Eosinophilic oesophagitis
Urticaria

Question 11

What is the disease process of COPD?

Answer 11

Cigarette smoke stimulates alveolar macrophages
These release neutrophil chemotactic factors, cytokine IL8, mediators (LTB4) and oxygen free radicals
Neutrophils then release proteases which causes alveolar wall destruction (Emphysema) and mucus hyper secretion (Chronic bronchitis)

Question 12

How can emphysema present clinically?

Answer 12

Reduced breath sounds upon auscultation
Reduced Diffusing Capacity for the Lungs for Carbon Monoxide (DLCO)
Black holes on chest X-ray or High Resolution CT

Question 13

What are some common presentations of COPD?

Answer 13

Chronic symptoms
Smoker
Non-atopic
Daily productive cough
Progressive breathlessness

Question 14

How does asthma compare to COPD

Answer 14

Question 15

What is meant by Asthma/COPD overlap syndrome?

Answer 15

In 5-10% of cases of COPD, the eosinophil is the main effector cell, so the disease shares some characteristics with asthma