Asthma

Question 1

Define asthma

Answer 1

chronic inflammatory airway disease characterised by:

• intermittent airway obstruction
• hyper-reactivity

Question 2

What are the 3 factors that contribute to airway narrowing in asthmatics?

Answer 2

1. bronchial muscle contraction
2. mucosal swelling/inflammation
   
   • mast cell & basophil degranulation –> release of inflammatory mediators
3. increased mucus production

Question 3

What can airway inflammation do to those with asthma?

Answer 3

causes:

• increased bronchial hyper-responsiveness
• recurrent episodes of wheezing, breathlessness, chest tightness, and coughing

which are usually associated with widespread but variable airway obstruction that is reversible either spontaneously or with treatment

Question 4

What are the risk factors of asthma?

Answer 4

• FHx
• allergens
• atopic Hx e.g. eczema, atopic dermatitis, allergic rhinitis

weak: nasal polyposis, obesity, GORD

Question 5

Summarise the epidemiology of asthma

Answer 5

30 million in Europe

25+ million ion US

affects 5-8% of population

Question 6

What are the symptoms of asthma?

Question 7

What are the signs of asthma o/e?

Answer 7

• dyspnoea
• tachypnoea
• cough (often nocturnal)
• expiratory wheeze (polyphonic)
• hyperinflated chest
• percussion: hyperresonant

Question 8

What are the primary investigations for ?asthma?

Answer 8

Pulmonary function tests (PFTs)

1. spirometry –> flow-volume loops –> calculate FEV1/FVC
2. bronchodilator reversibility (BDR) test

Question 9

What must be the results of the primary investigations for asthma for a diagnosis?

Answer 9

spirometry

• FEV1/FVC <70 or 80% of predicted

bronchodilator reversibility (BDR) test

• FEV1 after bronchodilator should show 200 mL< AND 12%< improvement.

Question 10

What investigation can be conducted if the primary tests are normal, and asthma symptoms still persist?

Answer 10

pulmonary function tests (PFTs) before & after a methacholine challenge.

• bronchoprovocation test,
• positive if methacholine –> 20%+ decrease using spirometry

Question 11

When measurement of peak flow variability indicated?

Answer 11

• if there is diagnostic uncertainty after initial assessment AND FeNO test
• normal spirometry OR
• obstructive spirometry + positive BDR BUT 39ppb≥ FeNO level (negative FeNO test)

Question 12

What must the results of a peak flow variability be for a positive asthma diagnosis?

Answer 12

20%+ variability

Question 13

What is the management pathway of asthma?

Answer 13

Question 14

Name some complications of asthma

Answer 14

• Severe/moderate exacerbations
• airway remodelling (obstructive) - similar to that of COPD
• oral candidiasis post-inhaled steroid use
• dysphonia post-inhaled steroid use
• > oesophageal candidiasis post-inhaled steroid use

Question 15

What is the prognosis of asthma?

Answer 15

Life expectancy is similar to that of general population

BUT airway remodelling is independent of inflammation i.e. anti-inflammatory Tx has no effect on long term remodelling