Respiratory: Obstructive Airway Disease

Question 1

What does an obstructive disease affect?

Answer 1

The airways

Question 2

What does a restive disease affect?

Answer 2

The lungs

Question 3

What the the obstructive airway syndromes?

Answer 3

o Asthma
o Chronic bronchitis
o Emphysema
o COPD/ asthma overlap syndrome (i.e. smokers with features of both asthma and COPD – aka COPD with reversibility

Question 4

What is the aetiology of airways obstruction in COPD?

Answer 4

• Bronchi are invaginated into the lung tissue
• Alveolar walls (or attachments) connect to lung
• Inflammation causes mucosa to become engorged causing obstruction
• Circular smooth muscle constricts causing narrowing of airway
• Cutting alveolar ‘guy ropes’ will collapse airway integrity
• Interthoracic pressure (as in emphysema) causes collapse

Question 5

What does extrinsic asthma mean?

Answer 5

The trigger has been identified

Question 6

What does atopic asthma mean?

Answer 6

It is allergic related with an IgE mediated response

Non-atopic, is non-allergic

Question 7

What are the three main factors in asthma that characterise the disease?

Answer 7

• Reversible airflow obstruction
• airway inflammation
• Airways Hyper-responsiveness

Question 8

What is the dynamic evolution of asthma?

Answer 8

• Bronchoconstriction – brief symptoms
• Chronic airway inflammation – exacerbations AHR
• Airway remodelling – fixed airway obstruction
  o scar tissue is laid down permanently which is irreversible

Question 9

What is the remodelling effects in asthma?

Answer 9

• basement membrane thickening
• collagen deposition
• smooth muscle; there can be hypertrophy

Question 10

What will trigger asthmatic inflammation?

Answer 10

Genetic disposition in combination with a particular trigger

Question 11

Describe airway inflammation

Answer 11

• Epithelial is detached

- Generally disordered mess

Question 12

How can airways inflammation be investigated?

Answer 12

Bronchial biopsy

Question 13

What drug can be used to normalise abnormal asthmatic airways?

Answer 13

Glucocorticoids

Question 14

What are the clinical symptoms of asthma?

Answer 14

• Episodic symptoms and signs
• Diurnal variability – nocturnal/ early morning
• Non-productive cough, wheeze
• Triggers
• Associated atopy (rhinitis, conjunctivitis, eczema)
• Family history of asthma
• Wheezing due to turbulent airflow

Question 15

How is Asthma diagnosed?

Answer 15

• History is primary diagnosis tool, examination would only really be useful (to hear wheeze, if examined early in the morning)
• Diurnal variation of peak flow rate
• Reduced forced expiratory ratio (FEV1, FVC 15%)
• Provocation testing leads to bronchospasm
  o Exercise
  o Histamine/ allergen

Question 16

What are the components in COPD that lead to obstruction and ongoing disease progression?

Answer 16

Mucociliary dysfunction
Inflammation
Tissue damage

Question 17

Describe the cellular signs that characterises chronic bronchitis?

Answer 17

o Chronic neutrophilic inflammation
o Mucous hypersecretion
o Smooth muscle spasm and hypertrophy
o Partially reversible

Question 18

Describe the cellular signs that characterises Emphysema?

Answer 18

o	Alveolar destruction
o	Impaired gas exchange 
o	Loss of bronchial support
o	Irreversible
o     Protease imbalance

Question 19

Describe the protease imbalance in emphysema?

Answer 19

• Protease production is increased leading to alveolar destruction and therefore emphysema
• Antiprotease function is a genetic factor which inhibits the action of protease

Question 20

What are the clinical symptoms of COPD?

Answer 20

• Chronic symptoms – non-episodic
• Smoking
• Non-atopic
• Daily productive cough
• Progressive breathlessness
• Frequent infective exacerbations
• Chronic bronchitis – wheezing
• Emphysema – reduced breath sound

Question 21

What are the chronic affects of COPD?

Answer 21

• Progressive fixed airflow obstruction
• Impaired alveolar gas exchange failure; decrease of PaO2 increase of PaCO2 4
• Pulmonary hypertension
• Right ventricular hypertrophy / failure (i.e. cor pulmonale)
• Death

Question 22

What are the non-pharmicological treatments for COPD?

Answer 22

o	Smoking cessation
	+/ - nicotine/ bupoprion
o	Immunisation – influenza/ pneumococcal
o	Physical activity
o	Oxygen – domiciliary
o	Venesection
o	Lung volume reduction surgery
o	Stenting

Question 23

What are the pharmicological treatments of COPD?

Answer 23

o	LAMA; tiotropium/ aclidinium
o	LABA; salmeterol/ formeterol
o	LAMA- LABA combo; aclidium/ formeterol
o	LABA-ICS combo; beclometasone- formoterol
o	PDE41 – roflumilast
o	Mucolytic – carbocisteine
o	Antibiotics – azithromycin