Management of Childhood Asthma

See also 'Diagnosing Childhood Asthma in Primary Care'

Asthma is the commonest respiratory disorder of children. Chronic inflammation of the bronchial mucosa and hyper-reactive airways result in bronchoconstriction and reversible airway narrowing. It typically presents with wheeze, dry cough, difficulty breathing and/or chest tightness.

Managing childhood asthma involves both an appreciation of current treatment practice but also a willingness to educate and support the child and their family in the longer term. Different phenotypes of childhood asthma are increasingly being recognised:¹

• Transient early wheezers where wheezing is commonly associated with viral upper respiratory infections. This is most likely to be grown out of by about 3 years, particularly in those children without a family or personal history of atopy.
• Non-atopic wheezers who again are likely to outgrow symptoms by early school age.
• Children who go on to develop a more persistent, atopic asthma, associated with raised IgE levels.

Acute asthma is a relatively common paediatric emergency. 40 UK deaths due to asthma in the 0 -14 years age range were recorded in 2006² which underlines the necessity to treat acute asthma as severe until proven otherwise and to refer children who respond inadequately to community treatment urgently to hospital.

Presentation

It is vital to recognise the severity of an acute asthma attack. Clinical signs are a poor indicator of the degree of airways obstruction and some with acute severe asthma may not appear distressed.

Always assess and record:

• Pulse rate
• Respiratory rate
• Degree of breathlessness (e.g. ability to complete sentences, to feed)
• Use of accessory muscles of respiration (feel the neck muscles for involvement in breathing)
• Amount of wheezing (with increasing severity, wheeze may become biphasic or less apparent)
• Degree of agitation and conscious level

Children should be monitored carefully and assessed repeatedly to determine the need for admission to secondary care or for transfer to HDU or PICU, where there are features of poorly responsive severe asthma or life-threatening asthma.

Investigations³

Include:

• Peak expiratory flow rate (PEF) in children over 5 years (use best of three readings, expressed as a % of personal best PEF).
• Oxygen saturation - should be available in primary care as low oxygen saturations (<92%) after initial bronchodilator therapy indicate a more severe subgroup of patients, in whom in patient treatment may be required.
• Chest X-rays and arterial blood gases are not routinely indicated as their information yield is rarely high.

Management³

With children over 2 years old:

• Give calm reassurance at all times.
• Children with life-threatening asthma or SpO₂<92% should receive high flow oxygen via face mask or nasal cannula.
• Inhaled beta₂-agonists are the first line treatment for acute asthma:
  • Delivery via a pMDI and spacer is preferred in mild to moderate asthma as there is less tachycardia and hypoxia compared to delivery via a nebuliser. Children under 3 years normally require a face mask attached to the spacer.
  • 2-4 puffs of beta₂-agonists repeated every 20-30 minutes according to clinical response may be sufficient for a mild attack but severe attacks may require up to 10 puffs: drug dosing should be individualised according to severity of attack and response.
  • Those children not improving after receiving up to 10 puffs of beta₂-agonists in primary care should be referred to secondary care. Continue to give further doses of bronchodilator whilst awaiting transfer.
    

    Low threshold for admission when: Attack late in day or at night time. Recent hospital admission or previous severe attack. Concerns re social circumstance or ability to cope at home.

  • Blue light those with poorly responding severe or life-threatening asthma, who should receive oxygen and nebulised beta₂-agonists (2.5-5 mg salbutamol or 5-10 mg terbutaline) in transit.
  • Nebulised beta₂-agonists should be repeated every 20-30 minutes - frequent intermittent doses are as efficacious as equivalent continuous nebulised doses.
• Steroid therapy - early use reduces hospital admissions and can prevent symptom relapse.
  • Oral steroids are of similar efficacy to intravenous preparations, which should reserved for the acutely unwell child who cannot swallow.
    

    Oral prednisolone in an acute asthma attack: Start early in the attack. Use 20 mg prednisolone for children aged 2-5 years and 30-40 mg for those over 5 years. For children on maintenance steroid treatment, give 2 mg/kg prednisolone to a maximum of 60 mg. Repeat the dose in children who vomit. 3 days' treatment is usually sufficient, but tailor according to the length necessary for recovery.

  • There is insufficient evidence that initiating or increasing inhaled steroids is effective in treating acute symptoms. Always give steroid tablets in preference. Children already on inhaled steroids should continue with their maintenance dose through the attack. Children not already on regular preventative treatment may benefit from initiating them as part of their long term management - but this should not be confused with the management of the acute attack.
• Additional emergency treatment:
  • IV salbutamol - early addition of a bolus dose (15 mcg/kg) can be a useful adjunct to nebulised treatment in some severe cases. Continuous infusion may be required where there is severe refractory asthma or concerns about reliability of inhalation. Doses exceeding 1-2 mcg/kg/min require PICU monitoring.
  • Nebulised ipratropium bromide - where symptoms are refractory to initial beta₂-agonist treatment, the addition of ipratropium bromide (250 mcg/dose, mixed with the nebulised beta₂-agonist solution) is of benefit in the first 2 hours of a severe asthma attack.
  • IV aminophylline should only be considered in children with severe or life threatening bronchospasm who have not responded to other treatment, in a HDU or PICU setting.
  • IV magnesium sulphate - inconclusive evidence of benefit in severe asthma.

Intermittent wheezing attacks in the under 2s are usually in response to viral infection and management remains controversial:

• Beta₂-agonist bronchodilators may offer marginal benefits to those under two with wheeze and should be considered if the child is symptomatically distressed. If they are not effective, consider the use of other treatment options. For mild to moderate attacks, use a pMDI plus spacer and face mask. Do not use oral beta₂-agonists, which have little evidence for efficacy in this context.
• Oral steroid treatment - consider 10 mg soluble prednisolone for up to three days in the management of moderate to severe asthma in infancy in the hospital setting.
• Ipratropium bromide can be combined with inhaled β2 agonist where there are more severe symptoms.

Non-drug³

• Allergen avoidance⁴ - commonly recommended in patients with asthma but lack of good evidence showing its efficacy.
  • House dust mite - a Cochrane review concluded that chemical and physical methods of house dust mite avoidance could not currently be recommended.⁵ However, some families are very committed to trigger avoidance and suggestions can include:
    • Complete bed-covering barrier systems
    • Removing all carpets
    • Removing soft toys from bed
    • High temperature washing of bed linen
    • Acaricides to soft furnishings
    • Improving ventilation with or without dehumidification
  • Pet allergy - no controlled trials looking at removing domestic pets. There is varied anecdotal evidence with some experiencing no benefit on removing the pet and others, with continuing exposure to the pet, developing some tolerance. However, it seems sensible not to get a cat or dog if someone in the family already has asthma.
• Dietary manipulation⁴ - studies looking at supplementation with Vitamin C, E, magnesium and fish oil have not shown significantly beneficial effects.
• Complementary and alternative therapies:
  • Buteyko technique - encourages patients to control their rate of breathing based on the idea that symptoms are due to hyperventilation and hypocapnia. Studies suggest no improvement in overall lung function when incorporated into the routine care of asthmatic patients.⁶ However, the technique may be helpful in providing symptomatic improvement.
  • Insufficient evidence to recommend acupuncture, herbal or Chinese medicines, homeopathy, hypnosis or relaxation therapies.
  • Air ionisers offer no benefit to the treatment of asthma.
• Smoking cessation advice to care givers and teenage asthmatics. Direct or passive smoking reduces lung function and increases need for rescue medication and long term 'preventer' treatment.
• Physical exercise therapy - may increase overall fitness but no specific benefit to asthma.
• Family therapy - where asthma is difficult to control, this may be a useful adjunct.
• Patient/carer education with aim to create partnership with family and child and confident self-care.⁷
• Written asthma action plans for self-management lead to consistently improved outcomes.⁸
• Consider care links e.g. to school and transition to adult services.⁷ Schools should have their own asthma policy; staff are not required to administer asthma drugs except in an emergency but most are supportive of children with asthma and receptive to training in managing asthma and the correct way to administer inhaled drugs.
• Links to local and national patient groups for support and information.⁷

Drug³

Chronic asthma

As for adult management of chronic asthma, current national guidelines advocate stepwise approach.³ Start at the step most appropriate to the initial severity of symptoms. Aim to achieve early control and then decrease treatment by stepping down to the lowest controlling step once stable. Always check concordance and reconsider diagnosis if response to treatment is poorer than anticipated.

Beta₂-agonists

• Short-acting beta₂-agonists work quickly and provide symptomatic relief. No benefits shown from regular dosing. Good asthma control is associated with little or no need for short-acting beta₂-agonist. Using two or more canisters of beta₂-agonists per month or >10-12 puffs per day is a marker of poorly controlled asthma that puts individuals at risk of fatal or near-fatal asthma.
  Thus, patients overusing inhaled short-acting beta₂-agonists should have their asthma management reviewed.
• Long-acting beta₂-agonists (LABAs) are useful in symptomatic control, particularly in the treatment of nocturnal asthma, but should not be used as relief for an acute attack. Any child using a LABA should also be using regular inhaled corticosteroid as failure to do this, increases the risk of life-threatening attacks. LABAs are the first choice add-on therapy where control on normal dose inhaled steroids remains suboptimum in the over 5s.
• Oral preparations of beta₂-agonists have been used extensively in the past with children but are less effective than inhaled preparations and have more side-effects.
• Parents often worry about the side-effects of beta₂-agonists, particularly sleep and behaviour disturbance, but evidence for links to hyperactivity is weak.⁹

Inhaled Corticosteroids

• Regular inhaled corticosteroids are recommended where:
  • Beta₂-agonists are being used more than 3 times per week.
  • A child is symptomatic more than 3 times per week.
  • Symptoms disturb sleep more than once a week
  • If a child over 5 has had an exacerbation in the last 2 years requiring systemic corticosteroids.
• They should be taken regularly and concordance may be an issue. Improvement in symptoms usually takes 3-7days.
• No impact on later development of asthma has been shown by early intervention with regular inhaled steroids in the episodically wheezy under fives.¹⁰
• Concerns surrounding systemic absorption abound. Systemic side-effects are unlikely at doses lower than 400 mcg beclomethasone diproprionate or equivalent. The dose likely to cause growth failure or adrenal suppression is unknown, though thought to be 800 mcg or above of beclomethasone diproprionate or equivalent daily. Children receiving these higher doses must be under the care of a respiratory paediatrician and receive a "steroid card". Similarly concerns regarding long-term reduction in bone-mineral density suggest that children should receive the minimum dose sufficient to control their asthma.
  Growth does not appear to be retarded with recommended doses of inhaled steroids - initial growth velocity (in the first year of treatment) may be reduced but there does not appear to be an effect on ultimate adult height.¹¹ Nonetheless, regularly monitor the height of children on prolonged high-dose inhaled steroid treatment.
• Candidiasis of the throat and mouth may occur, particularly with higher doses of inhaled corticosteroids. Strategies to reduce the risk include use of a spacer and rinsing the mouth with water or cleaning the teeth following inhalation.

Leukotriene receptor antagonists

• These are an option as 'add on' therapy to poorly controlled asthma. In the over 5's, a LABA and inhaled corticosteroids to a dose of 400 mcg beclomethasone diproprionate or equivalent should be trialled before their use.
• Leukotriene receptor antagonists improve lung function, decrease exacerbations and improve symptoms in some patients but there appears to be wide individual difference in response.
• They should not be considered "steroid-sparing".

Theophyllines

• These are another option as 'add on' therapy for the over 5's.
• There is little evidence demonstrating the increased benefit of one particular 'add on' approach (further increase dose of inhaled steroids 800 mcg beclomethasone diproprionate, leukotriene receptor antagonist, oral theophylline or slow release oral beta₂-agonist) to guide choice.
• Theophyllines and oral beta₂-agonists are associated with higher risk of side-effects.
• With any add on therapy, have a trial for a predetermined time period and stop the therapy if, on assessment, it has no benefit.

Referral¹⁰

Consider referral to specialist colleagues (respiratory paediatrician or specialist children's asthma nurse):

• Children receiving high dose inhaled steroids (800 mcg beclomethasone diproprionate or equivalent)
• Poor response to 400 mcg beclomethasone diproprionate or equivalent and GP unconfident at managing add-on treatments
• Under 5 with drug delivery problems
• Uncertainty about the diagnosis
• Recurrent hospital admission
• History of severe acute asthma requiring PICU admission

Immunisation

Influenza vaccine¹² - asthmatic children who require continuous or repeated use of inhaled/systemic steroids or with previous exacerbations requiring hospital admission should be immunised. If children receive repeated systemic steroids sufficient to cause immunosuppression they also require pneumococcal vaccination.

Drug delivery devices^3,13,14

• MDI plus spacer device is the first-line choice for the delivery of inhaled corticosteroid therapy in those aged over 5.
• Where poor compliance with MDI and spacer is likely to jeopardise good asthma control, alternative devices should be considered whilst still looking to minimise systemic absorption.
• For those aged less than 5, corticosteroid and bronchodilator therapy should be delivered via MDI/Spacer and facemask combination. Nebulisers may be considered where MDIs and spacers are not effective or if the child's clinical condition is poor.
• Children and their carers need to be trained in the use of their chosen device prior to prescribing and suitability reviewed looking at compliance and technique.

• Reduced quality of life
• Reduced growth, usually as a result of poor control rather than treatment
• Psychological morbidity - although differences appear to be the result of poor health rather than asthma itself¹⁵
• Absence from school and educational disadvantage
• Death