Asthma

Question 1

Definition of Asthma

Answer 1

A chronic inflammatory condition of the airways characterized by bronchial constriction. It is associated with atopy

Question 2

Name some triggers of asthma - 7

Answer 2

• pollen
• pets
• dust
• smoke
• cold weather
• exercise
• NSAIDs

Question 3

Pathophysiology of Asthma

Answer 3

This chronic inflammation is caused by 2 responses:

Immediate – a type 1 hypersensitivity reaction caused by IgE antibodies recognizing antigens and causing mast cell degranulation. This leads to bronchoconstriction

Late Phase – a type 4 hypersensitivity reaction where eosinophils, mast cells, lymphocytes and neutrophils are released and cause chronic inflammation.

Question 4

Risk factors of asthma - 5

Answer 4

• FH
• PMH of atopy (often associated with atopic triad of asthma, allergic rhinitis and atopic eczema)
• maternal smoking
• viral infections
• lower socioeconomic status

Question 5

Symptoms of asthma - 4

Answer 5

1. wheeze
2. dyspnoea
3. cough (worse at night due to raised PNS activity)
4. chest tightness

Question 6

Signs of Asthma - 5

Answer 6

1. Tachypnoea
2. hyperinflated chest
3. hyper-resonance on percussion
4. decreased air entry
5. wheeze on auscultation

Question 7

Investigations of Asthma

Answer 7

1. Spirometry
2. Peak Flow diary
3. Bloods - IgE and Eosinophils raised
4. CXR - to exclude other causes of wheeze
5. Fractional exhaled nitric oxide

Question 8

Positive spirometry results

Answer 8

Will indicate obstructive lung disease findings:
* reduced FEV1
* Reduced FEV1:FVC ratio (will be less than 0.7)

These should be performed before and after a bronchodilator - after the BD, results should be normal.

Question 9

Positive Peak Flow Diary Results

Answer 9

At least 20% variablity after monitoring twice daily for 2-4 weeks

Question 10

Positive Fractional Exhaled Nitric Oxide Results and why is it done

Answer 10

This looks at the NO in a single exhaled breath, as NO is a marker for eosinophilic inflammation in lungs

An NO level of over 40ppb is positive

Question 11

Differentials of Asthma - 8

Answer 11

1. Bronchiectasis
2. COPD (smoker, productive cough)
3. Cystic Fibrosis
4. GORD
5. Heart failure
6. Lung cancer
7. TB
8. Pertussis

Question 12

Non pharmacological management of asthma - 3

Answer 12

1. smoking cessation
2. avoidance of triggers
3. review inhaler technique

Question 13

Pharmacological stepwise approach to Asthma management - 4

Answer 13

1. SABA (salbutamol)
2. low dose ICS (beclometasone)
3. add LABA (salmeterol). If no benefit, stop and increased ICS dose
4. Trial of oral leukotriene receptor antagonist (montelukast) , high-dose steroid, oral beta agonist and oral theophylline

Question 14

ADRs of Beta Agonists - 5

Answer 14

1. Tremor
2. palpitations
3. headache
4. anxiety
5. hypokalaemia

Question 15

Signs of an acute asthma exacerbation - 3

Answer 15

1. difficulty breathing
2. tachypnoea
3. wheeze

Question 16

Signs of a Severe Asthma Attack - 4

Answer 16

1. inability to finish sentences
2. respiratory rate is >25
3. peak flow is 33-50% of baseline
4. HR >110bpm

Question 17

Signs of a life threatening asthma exacerbation - 6

Answer 17

1. Peak flow <33% of baseline
2. a silent chest
3. confusion or drowsiness
4. Cyanosis
5. Hypotension
6. Bradycardia

These pts should be urgently admitted to intensive care

Question 18

Investigations of acute asthma

Answer 18

• Blood test (FBC, CRP) - to look for cause of attack e.g. infection
• CXR - to exclude pneumothorax or consolidation
• ABG - respiratory alkalosis is expected

Question 19

Management of an acute asthma exacerbation - 6

Answer 19

1. ABCDE approach
2. Ensure patent airway
3. Nebulisers - salbutamol or ipratropium
4. Steroids - oral prednisalone or IV hydrocortisone
5. IV magnesium sulphate
6. IV aminophylline