Airflow Obstruction

Question 1

What FEV1/FVC cutoff is used to diagnose airflow obstruction?

Answer 1

Less than 70%.

Question 2

What FEV1/FVC ratio is considered normal?

Answer 2

Greater than 70%.

Question 3

Is the 70% cutoff more applicable to younger or older individuals?

Answer 3

Older population.

Question 4

What are the three main mechanisms of airflow obstruction?

Answer 4

Airway blockage, airway inflammation, and emphysema.

Question 5

How does resistance relate to airway radius?

Answer 5

Resistance is inversely proportional to the fourth power of radius.

Question 6

What happens to airway cross-sectional area as you move peripherally in the lung?

Answer 6

It increases markedly.

Question 7

What causes early symptoms in airway diseases?

Answer 7

Narrowing of large airways.

Question 8

Can small airway damage occur without symptoms?

Answer 8

Yes, major damage can occur without symptoms.

Question 9

Name three common obstructive airway diseases.

Answer 9

Asthma, COPD, and Bronchiectasis.

Question 10

What is asthma?

Answer 10

A heterogeneous disease marked by chronic airway inflammation and variable airflow limitation.

Question 11

Name acute airway changes in asthma.

Answer 11

Smooth muscle contraction, mucus hypersecretion, plasma leakage, edema, sensory nerve activation.

Question 12

Name chronic airway changes in asthma

Answer 12

Subepithelial fibrosis and smooth muscle hypertrophy.

Question 13

What is a high FeNO value in adults supportive of asthma?

Answer 13

> 50 ppb.

Question 14

What FeNO value is supportive of asthma in children?

Answer 14

> 35 ppb.

Question 15

What does elevated FeNO indicate?

Answer 15

Eosinophilic inflammation and predicts steroid responsiveness.

Question 16

What is the gold standard test for eosinophilic inflammation?

Answer 16

Sputum eosinophilia.

Question 17

What type of inflammation is shown by peripheral blood eosinophilia?

Answer 17

Type 2 (T2) inflammation.

Question 18

What is used in reversibility testing for asthma?

Answer 18

400 micrograms of salbutamol (SABA).

Question 19

What result indicates a positive bronchodilator response?

Answer 19

Increase in FEV1 by ≥200 mL and 12%.

Question 20

What increase in FEV1 gives greater confidence in asthma diagnosis?

Answer 20

≥400 mL and 15%.

Question 21

How often should PEFR be measured during monitoring?

Answer 21

Twice daily for 2–4 weeks.

Question 22

What PEFR variability is considered significant by NICE?

Answer 22

> 20%.

Question 23

What PEFR variability is considered significant by GINA?

Answer 23

> 10%.

Question 24

What substance is used in bronchial challenge testing?

Answer 24

Mannitol.

Question 25

What does a greater FEV1 reduction with mannitol indicate?

Answer 25

Greater airway hyperresponsiveness.

Question 26

What mediators are released during mannitol testing?

Answer 26

PGD, LTE4, histamine.

Question 27

What is allergic/atopic asthma associated with?

Answer 27

Childhood onset, eosinophilic inflammation, and identifiable triggers.

Question 28

What characterizes non-allergic asthma?

Answer 28

Eosinophilic, neutrophilic, or paucigranulocytic inflammation.

Question 29

What defines asthma with persistent airflow limitation?

Answer 29

Fixed or partially reversible obstruction.

Question 30

What is a key feature of asthma in obesity?

Answer 30

Prominent symptoms with little eosinophilic inflammation.

Question 31

What is COPD?

Answer 31

A preventable and treatable disease with persistent respiratory symptoms and airflow limitation.

Question 32

Name three common symptoms of COPD.

Answer 32

Breathlessness, cough, sputum production.

Question 33

What is the most common cause of COPD?

Answer 33

Smoking.

Question 34

Name other risk factors for COPD besides smoking.

Answer 34

Biofuels, occupational exposure, genetics, chronic asthma, recreational drugs.

Question 35

What are the key pathological features of chronic bronchitis?

Answer 35

Mucus gland hypertrophy, smooth muscle hypertrophy, goblet cell hyperplasia, inflammation, and excess mucus.

Question 36

What defines emphysema?

Answer 36

Destruction and enlargement of airspaces distal to terminal bronchioles without fibrosis.

Question 37

How does emphysema cause airflow obstruction?

Answer 37

Loss of radial traction and reduced elastic recoil.

Question 38

What is the result of reduced alveolar support in emphysema?

Answer 38

Airway narrowing and collapse.

Question 39

Why does airflow obstruction cause hypoxia?

Answer 39

Due to ventilation/perfusion mismatch.

Question 40

What is a consequence of chronic hypoxia on pulmonary arteries?

Answer 40

Pulmonary hypertension.

Question 41

What condition results from chronic pulmonary hypertension due to lung disease?

Answer 41

Cor pulmonale (right-sided heart failure).

Question 42

What is bronchiectasis?

Answer 42

Abnormal airway dilation with chronic sputum, infection, and airflow obstruction.

Question 43

What is the most common fatal genetic cause of bronchiectasis?

Answer 43

Cystic fibrosis.

Question 44

How is bronchiectasis diagnosed?

Answer 44

High Resolution CT (HRCT).

Question 45

How does bronchiectasis cause airflow obstruction despite dilation?

Answer 45

Due to secretions and fibrosis in small airways.