Obstructive Airway Disease 1

Question 1

What is obstructive airway disease?

Answer 1

Any respiratory disease characterised by air trapping caused by either decrease airway diameter or increased airway secretions, or both

Question 2

what are 3 obstructive airway disease?

Answer 2

AsthmaChronic bronchitisEmphysema

Question 3

What is asthma/ COPD overlap syndrome?

Answer 3

Not clearly defined but patients with features of asthma and COPD (e.g. atopic smoker with partially reversible airway obstruction) - COPD with reversibility and eosinophilia who are steroid responsivE

Question 4

What causes the turbulent airflow in asthma and COPD?

Answer 4

Mucosa and sub-mucosa become inflamed and invaginate and therefore obstruct airflow

Question 5

what type of leukocytes are involved in COPD and asthma?

Answer 5

COPD = neutrophilAsthma = eosinophil

Question 6

How can the tone of the smooth muscle be described in COPD and asthma?

Answer 6

COPD = hypertrophicAsthma = twitchy

Question 7

What 3 sets of words can be used to describe asthma?

Answer 7

Early onset/ late onsetAtopic (allergic)/ non-atopicExtrinsic (external factor)/ intrinsic (internal factor)

Question 8

What is the asthma triad?

Answer 8

Airway inflammationReversible airflow obstructionAirway hyperresponsivenes (hyperreactivity)

Question 9

What is the evolution of asthma?

Answer 9

Bronchoconstriction (brief symtpoms)Chronic airway inflammation (exacerbations airway hyperresponsiveness)Airway remodelling (fixed airway obstruction = COPD like symptoms)

Question 10

What are the hallmarks of asthma remodelling? (3)

Answer 10

Basement membrane = thickenedSubmucosa = collagen depositionSmooth muscle = hypertrophy

Question 11

What is the inflammatory cascade in asthma? + treatment?

Answer 11

Genetic predisposition + triggers (viruses, allergen, chemical, nutrition) - avoidanceEosinophilic inflammation - anti-inflamatory (corticosteroid)TH2 cells release mediators (Interleukins e.g. IL-12, IL-4, IL-5) - anti-leukotriene/ histamine, anti-IgE, anti-IL5)Twitchy smooth muscle (hyper-reactivity) - bronchodilators (beta-2 agonists, muscarinic antagonists)

Question 12

What are examples of the environmental factors that can affect asthma?Genetic factors?

Answer 12

Age, gender, obesity, infeciton, atopic status, allergin exposureGenetic = Epithelial-specific asthma gene signature

Question 13

Examples of some asthma triggers?

Answer 13

Animal danderDust mitesPollensFungiExercise Viral infectionSmokeColdChemicalsdrugs (NSAIDs, beta-blockers)

Question 14

What are the clinical signs of asthma?

Answer 14

Episodic symptoms and signsdiurnal variability (nocturnal/ early morning)non-productive cough, wheezetriggersassocaited atopyfamily history

Question 15

What can be used to help diagnose asthma?

Answer 15

History and examinationdiurnal variation of peak flow rateReduced forced expiator rate (FEV1/FVC 15%)Provocation testing leads to bronchospasm

Question 16

What can be used to provoke asthma in the clinical setting?

Answer 16

ExerciseHistamine/ metacholine/ mannitol

Question 17

What are the 3 components of COPD caused by noxious particles or gases?

Answer 17

Mucociliary dysfunctionNeutrophilic inflammationTissue damage(these lead to the development of obstruction and ongoing disease progression)

Question 18

What are the characteristics of COPD? (2)

Answer 18

ExacerbationsReduced lung fucntion

Question 19

What is the disease process in COPD?

Answer 19

Inhaled noxious chemicals causes inflammation of the lungs (if normal protective mechanisms aren’t working properly)Cigarette smoke activated macrophages and airway epithelial cells which release neutrophili chemotaxis factorNeutrophils and macrophages then releases proteases that break down lung parenchyma (emphysema)and stimulate mucous hyper secretion (chronic bronchitis)Cytotoxic T cells may also be involved

Question 20

In COPD, what is there an imbalance of?

Answer 20

Proteases and anti-proteases (e.g. alpha1-antitrypsin)

Question 21

What are the features of chronic bronchitis?

Answer 21

Chronic neutrophilic inflamationmucus hypersecretionmucociliary dysfunctionaltered lung biomesmooth muscle spasm and hypertrophyPartially reversible

Question 22

What are the features of emphysema?

Answer 22

Alveolar destructionImpaired gas exchangeLoss of bronchial supportIrreversible

Question 23

What are indicative of high risk COPD?

Answer 23

2 exacerbations or more within the past year or FEV2 less than 50%

Question 24

Clinical features of COPD?

Answer 24

Chronic symptoms (not episodic)SmokingNon-atopicDaily productive coughProgressive breathlessnessFrequent infective exacerbationsChronic bronchitis = wheezingEmphysema = reduced breath sounds

Question 25

What is the chronic cascade in COPD?

Answer 25

Progressive fixed airflow obstructionImparied alveolar gas exchangeRespiratory failure (decrease PaO2, increased PaCO2)Pulmonary hypertensionRight ventricular hypertrophy/ failure (for pulmonale)Death (stopping smoking arrests further decline in lung volume)

Question 26

Corticosteroid and bronchodilator response in asthma v COPD

Answer 26

Good response in asthmaPoor response in COPD