Asthma

Question 1

Describe when and how asthma may initially present?

(symptoms)

Answer 1

• May initially present with wheeze
• Before 4yo wheeze is very common due to children having small airways which can be easily obstructed by inflammation from illness. The diagnosis of asthma is therefore only given after the age of 4.
• The child should suffer from wheeze as well as interval symptoms in between the acutely unwell episodes.
• Interval symptoms include a night cough as well as getting wheezy with exercise/cold/allergens.
• It is likely there will also be a PMH/FH of atopy.

Question 2

Why is it difficult to diagnosis asthma before 4 years old?

What are the two patterns of wheeze in toddlers?

Answer 2

• Diagnosis can be difficult since approximately half of all children wheeze at some time during the first 3 years of life.
• In general there are two patterns of wheezing: transient early wheezing and persistent and recurrent wheezing.

Asthma often begins as wheezing in infants with respiratory infections. If these episodes remain mild and infrequent then asthma does not usually persist into the school years. This is classed as transient early wheezing and is thought to result from small airways being more likely to narrow and obstruct due to inflammation and aberrant immune responses to viral infection. Here a family history of asthma or allergy is not a risk factor but maternal smoking is.

Recurrent and persistent wheezing on the other hand can affect both preschool and school-aged children and may be triggered by many stimuli. The presence of IgE to common inhalant allergens is associated with persistence of wheezing beyond the preschool years. This coupled with evidence of allergy to one of more of these allergens is termed atopic asthma. The patients have persistent symptoms and decreased lung function and there is a strong association with other atopic diseases.

Question 3

What are the key features of history and examination that support a diagnosis of asthma?

(6)

Answer 3

• Recurrent Polyphonic wheeze
• Symptoms worse at night and in early morning
• Symptoms have a trigger i.e. pets
• Interval symptoms between exacerbations
• Personal/Family history
• Positive response to asthma therapy

Question 4

What other common clinical conditions can mimic asthma?

Answer 4

• GORD
• Cystic fibrosis
• Viral induced wheezing
  
  • Viral induced wheeze is verycommon and is thought to affect around half of children up to the age of 3
  • It is most common in boys and usually resolves around the age of 5, probably due to an increase in airway size
• Bronchiolotis
• Croup
• Foreign body
• Anaphylaxis
• Cogenital abnormality of lung or airway

Question 5

What are the clinical features of acute moderate asthma exacerbation?

Answer 5

• Marked pulsus paradoxus (difference between sytolic BP on inspiration & expiration)
• O2 greater than 92%
• PEFR greater than 50%
• No clinical features of severe

Question 6

Treatment of moderate acute asthma exacerbation?

Answer 6

• Short acting B2 agonist (SABA) via spacer, 2-4 puffs, increasing by 2 puffs every 2 minutes to 10 puffs if required
• Consider oral prednisolone
• Reassess within 1 hour

Question 7

What are the clinical features of acute severe asthma exacerbation?

Answer 7

• PEF less than 50%
• Respiratory distress
• Broken speech (too breathless to talk or feed)
• Use of accessory muscles
• O2 stats less than 92%
• RR >50/min or 30/min depending on age
• Pulse >130

Question 8

Treatment for severe acute exacerbation of asthma?

Answer 8

Treatment:

• Oxygen + give short acting B2 agonist (10 puffs via spacer or nebuliser)
• Oral prednisolone or IV hydrocortisone should be give and nebulised ipratropium bromide if a poor response
• Repeatbronchodilators every 20-30 minutes.

Question 9

What are the clinical features of life threatening asthma?

Answer 9

• PEF less than 33%
• Silent chest
• Altered consciousness
• Confusion
• Decreased RR
• Hypotension
• O2 less than 92%
• Cyanosis
• Poor respiratory effort

*

Question 10

Treatment for life threatening asthma?

Answer 10

Treatment:

• Oxygen + nebulised B2 agonist plus ipratropium bromide
• IV hydrocortisone should be given and the case discussed with a senior clinician and the PICU team.
• Repeat bronchodilators every 20-30 minutes.

Question 11

What is in each of the following inhalers contain? (blue, brown, purple, green, orange, grey)

Answer 11

Blue: salbutamol Brown: beclametasone Purple: salmeterol + fluticasone (seretide) Green: salmeterol Orange: fluticasone (alternative inhaled corticosteroid) Grey: ipratropium bromide

Question 12

What is the treatment algorithm for mild/moderate exacerbation of asthma in children?

Question 13

What is the treatment algorithm for life threatening exacerbation of asthma in children?

Answer 13

Question 14

What is the stepped guideline of treatment for non acute asthma? age 5-12

Answer 14

Step 1: Inhaled SABA (salbutamol) as required

Step 2: Add inhaled steroid (beclometasone) 200-400mcg/day

Step 3: Add LABA (salmeterol) and assess control - (if control inadequate: continuw and increase steroid to 400mcg/day, if still no response trail leukotroene receptor antagonist or theophylline)

Step 4: Increased inhaled steroid to 800mcg/day

Step 5: Use daily oral steroid tablet (prednisolone) + refer to specialist

Question 16

How do these drugs work? Give examples

1. B2 agonists (SABA)
2. Anticholinergic bronchodilators
3. Inhaled cortico-steroids (ICS)
4. Long acting B2 bronchodilators (LABA)
5. Methylxanthines
6. Leukotriene inhibitors (LTRA)
7. Oral steroids

Answer 16

1. B2 agonists – e.g. Salbutamol and Terbutaline – these act on betareceptors to directly cause bronchodilation. They can be less effective invery young children as they have fewer active beta receptors.
2. Anticholinergic bronchodilators – e.g. Ipratropium bromide – these have asimilar effect to beta agonist but act via a different receptors (the sympathetic system) to achieve their affect.
3. Inhaled steroids – e.g. Budesonide, Beclometasone, Fluticasone and Mometasone – these are a preventative treatment that act to prevent to creation of inflammatory proteins and hence reduce any response caused by the release of IgE or other chemical.
4. Long acting B2 bronchodilators – e.g. Salmeterol and Formoterol – act on the B2 receptors for longer than Salbutamol
5. Methylxanthines – e.g. Theophylline – a complicated pathway that leads to the relaxation of bronchiole smooth muscle
6. Leukotriene inhibitors – e.g. Montelukast – taken orally in children under 5 instead of a LABA. This drug is an antagonist that blocks the action of leukotriene and hence reduces the bronchoconstriction otherwise caused by it.
7. Oral steroids – e.g. Prednisolone – same action as inhaled steroids but more potent and greater systemic effects (and also side effects).

Question 17

How is asthma control assessed during childhood?

Answer 17

• Assess symptoms
• Measure lung function
• Check inhaler technique and adherence

Question 18

How should you advise a parent on how to care for a child with asthma?

Answer 18

Provide an asthma management plan.

Educate on when to use drugs, how to use them, what they are for, how often and how much and what to do if the asthma gets worse.

The child and parent need to know that increasing cough, wheezing, breathlessness and difficulty in walking, talking, sleeping or decreasing relief from bronchodilators all indicate poorly controlled asthma.

A supply of oral steroids can also be provided if necessary.

Question 19

What is the stepped guideline of treatment for non acute asthma? age under 5

Answer 19

Step 1: Inhaled SABA (salbutamol) as required

Step 2: Add inhaled steroid (beclometasone) 200-400mcg/day

Step 3: Add leukotriene receptor antagonist (montelukast) to inhaled steroid (in children under 2 go straight to step 4)

Step 4: Refer to respiratory paediatrician

(Same step 1+2 but step 3 different as LABAs dont work well in young infants because not enough B2 receptors for them to work on)