Asthma

Question 1

Asthma Symptoms

Answer 1

Wheeze
Dyspnoea
Chest tightness
Dry cough (paroxysmal)
Sputum (sometimes)

Question 2

Features suggestive of asthma

Answer 2

Variable symptoms
Triggers - exercise, cold, smoke, pollen
Temporal variation
History of childhood asthma/bronchitis
Eczema
Hayfever

Question 3

What would be considered obstruction in spirometry?

Answer 3

FEV1 <80% predicted
or
FEV1/FVC <70%

Question 4

Asthma Investigations

Answer 4

Spirometry
>Full pulmonary function
>Reversibility (beta2 agonist)
>Reversibility (steroids)

If spirometry normal:
>Peak flow
>Bronchial provocation
>Nitric oxide

Extra:
CXR
Skin prick testing (atopy)
Total and specific IgE (atopy)
Full blood count (eosinophilia = might be atopy)

Specialist:
Airway response to methacholine/histamine - FEV1% decrease as dose increasses
Exhaled NO - increased in asthma

Question 5

What would be considered significant reversibility in response to bronchodilator?

Answer 5

FEV1 increase of >200mL

No reversibility could mean SEVERE bronchoconstriction as well as NO bronchoconstriction

Question 6

Asthma Differential Diagnoses

Answer 6

Differentiate from other causes of wheeze:
Localised AFO/Foreign body
Inspiratory Stridor
Tumour

Other AFO causes:
COPD
Bronchiectasis
Bronchiolitis
CF

Probably not asthma if:
Clubbing, cervical lymphadenopathy
Stridor
Assymetrical expansion
Dull percussion
Crepitations

Question 7

Asthma Severity Scoring

Answer 7

Moderate

• HR < 110
• RR < 25
• PEF 50-75% predicted/best
• SaO2 >92%
• PaO2 >8kPa
• Complete sentences

Severe - any one of:

• HR >110
• RR >25
• PEF 33-50% predicted/best
• SaO2 and PaO2 should be normal
• Hindered speech

Life-threatening - any one of:

• Impaired consciousness, confusion
• HR >130 or bradycardic
• PEF <33% predicted/best
• Cyanosis
• SaO2 <92%
• PaO2 <8kPa
• PaCO2 should be normal
• No proper speech

Near fatal:
- Raised PaCO2

Question 8

Asthma Management (Chronic) + Example Drugs

Answer 8

• SABA - salbutamol
  > ICS - beclomethasone
  > Inhaled LABA - salmeterol, (LABA + ICS combined in Fostair)
  > Consider increased ICS or adding 4th drug
  > Refer
  > LTRA (montelukast) + Increased ICS
  > Long term oral steroids - prednisolone

4th drugs:

• Theophylline - PDE Inhibitor
• LAMA - tiotropium bromide
• oral beta-agonists

Alternative drugs:

• Omalizumab (anti-IgE)
• Mepolizumab (anti-IL-5)
• Immunosuppressants (methotrexate, ciclosporin)

Avoid NSAIDs and beta-blockers

Question 9

Asthma Management (Acute)

Answer 9

Moderate Exacerbation:

• oral prednisolone 7d
• SABA more frequently (upto 2/hr)
• Increase ICS/LABA?
• Assess in 24hr

Severe Exacerbation:

• Hospital admission
• Oral/IV steroids
• Nebulised bronchodilators
• O2
• IV Mg if no response
• Antibiotics if pneumonia
• CXR incase of PTX
• ITU if life-threatening (anaesthesia, intubation)
• EC CO2 R may be life-saving

Question 10

Measuring Asthma Control in Children

Answer 10

S - SABA usage/week
A - Absence from school?
N - Nocturnal symptoms?
E - Exertional symptoms?

Question 11

Asthma Management (Chronic) in Children

Answer 11

• SABA as required
  > Regular preventer as in adults in >3x weekly symptoms
  (start low, use LTRA in under 5s)
  > Review after 2 months
  > Add-ons: LABA (MDI) (salmeterol), LTRA (montelukast only), Increased ICS
  > High-dose therapies (<5s refer, >5s medium dose ICS and consider referral)
  > experimental medicine, compliance, ?diagnosis

Do not use LABA without ICS
Use spacer (4x delivery)
Under 8s can’t use DPI
No at home nebulisers

Question 12

Asthma Management (Acute) in Children

Answer 12

Mild:
- SABA + spacer (maybe prednisolone)

Moderate:
- SABA via nebuliser + prednisolone
> SABA and Ipratropium via nebuliser + prednisolone

Severe:

• IV SABA, aminophylline, Mg, Hydrocortisone
• intubate and ventilate

Start treatment, reassess in 1hr
Step up/down as appropriate
Use oral steroids in acute

Question 13

Asthma Non-pharmacological management

Answer 13

Patient education, self-management
Inhaler technique
Smoking cessation
Flu/pneumococcal vaccines
Address comorbidities
Step down treatment when controlled
Allergen avoidance
Thermoplasty
Remove from environment of trigger

Question 14

Asthma Detailed Pathology

Answer 14

Activation of Th2 subset of T-cells
Expression of IL-3, 4, 5, 13 and GM-CSF in response to allergens.
Eosinophil inflammation with varying degrees of mast cell activation are the characteristics of pathological lesion.
More chronic disease is associated with destruction of the normal structure of the tissue with subsequent repair mechanisms occurring.

Year-round symptoms often result from allergy to house dust mite or animals
Seasonal from pollens (tree in March-May, grass June-July, weeds July-Aug)
Non-allergic or intrinsic asthma has same pathological changes but allergic triggers not involved in cause.

Question 15

Risk factors for asthma

Answer 15

Genetic atopy
Occupational aerosols
Smoking - maternal/grandmother in utero

Possible

• Obesity
• Diet
• Reduced microbe exposure
• Indoor pollution