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Treating childhood asthma in primary care

Charles Broomhead
MB ChB FRCGP DA DRCOG
GP
Sutton Coldfield GP Trainer and Honorary Clinical Lecturer
Birmingham University

Studies have shown that one-third of children with asthma have had five or more episodes of wheezing in the previous 12 months.1 Serious consequences arise from this, including the loss of education, reduction in physical exercise and associated opportunities for socialisation and adverse effects within the family unit. We have the tools with which to treat the condition, but somehow often fail to exploit them effectively. The reasons for this are complex but there are strategies that healthcare workers can adopt to help to maximise control.

The role of the practice nurse
The successful management of childhood asthma demands not only a thorough knowledge of the subject but much more besides. With the advent of primary care nurse-led respiratory clinics, the quality of overall care has undoubtedly improved. Not only do many nurses now have the skills to diagnose and manage asthma, but can also often prescribe in their own right.
When a child is diagnosed as having asthma, there are always many concerns and questions to be answered. Longer appointments in a dedicated clinic mean that healthcare professionals can devote time to deal with these and educate the patient and their parents about the problem. It takes time and skills to choose an appropriate inhaler device and to teach the  patients how to use it, while anxieties about medication and possible side-effects need to be addressed to maximise concordance.
Time spent in education will ultimately pay dividends in improving care and outcomes for the patient and their family. Many patients find nurses easier to talk to than their GP colleagues and it is important wherever possible to establish the foundations for a trusting relationship. Education about asthma is an ongoing process and one that is reinforced by the provision of material to take away from the consultation. Written management plans underpin the management process and provide a valuable source of information, particularly when things start to go wrong.
Others, such as teachers, who are involved in supervising or caring for children, also need to have a basic understanding of the management plan. They should know at least the principles of treatment and understand that the child may need access to relief medication during the day. Having an inhaler at school but locked away in a cupboard is of little value and failure to recognise the signs of a deteriorating condition may lead to severe consequences. School authorities are fortunately beginning to recognise their responsibilities in this regard and are putting measures in place to deal with these issues.

Principles of management
As is well known, asthma is a chronic inflammatory condition affecting the airways. The result of this is that they become hyper-reactive, constricting easily in response to a wide range of stimuli and causing the familiar symptoms of cough, wheeze and shortness of breath.
The fundamentals of treatment remain the same whatever the age of the patient. An anti-inflammatory drug, such as an inhaled corticosteroid, is used as regular preventive therapy and additional relief medication, such as a short-acting ß-2 agonist, is taken when necessary to control any symptoms that remain.
Inhaling asthma medication is generally the preferred delivery route, allowing smaller doses to be delivered directly to the lungs where they act more rapidly with less systemic side-effects than when taken orally. Choice of inhalation device is critical in both adults and children to ensure that the medicines that we prescribe actually reach their intended site of action.
While the aims for asthma management will vary a little from patient to patient, they will include:
•    Reducing symptoms to a minimum during the day and at night
•    Little or no need to use relief medication.
•    No exacerbations.
•    No limitations on physical activity.
•    Achievement of normal or best possible lung function.

An additional goal in the case of children is that normal growth should occur and should not be restricted either as a result of the asthma or its treatment.
A fundamental difference between treating children and adults is that in the case of a child there is always at least one and often several additional participants in the consultation process. One or both parents will need to have their views on management taken into consideration. Their concerns about medication will need to be addressed and they will need to be educated about their child's condition. Those acting "in loco parentis", such as teachers, will also need to understand the principles of management and what to do when things start to go wrong.

Diagnosis
Asthma should be suspected in any child who wheezes, but all children who wheeze do not have asthma. Other possible causes include respiratory tract infections, inhaled foreign bodies, cystic fibrosis and gastro-oesophageal reflux. This list is by no means exhaustive. A high index of suspicion of asthma should be maintained in the case of any child who has a history of recurrent wheezing, chronic cough (particularly at night), or shortness of breath on exercise. Where there is a family history of asthma or other atopic conditions such as eczema or allergic rhinitis the diagnosis becomes far more likely.
Clinical signs that may suggest a diagnosis of asthma include widespread expiratory wheeze, tachycardia, an increased respiratory rate or even deformity of the chest wall if the condition is long-standing or inadequately untreated. The absence of wheeze does not exclude asthma, particularly when the condition is severe and airflow is massively reduced.
Asthma is a condition which is usually diagnosed on clinical grounds, the role of tests and investigations being to confirm or refute the diagnosis. Making the diagnosis in very young children can be extremely difficult but the problem becomes easier in the older child when tests such as peak flow measurements can be performed.
Observing the response to bronchodilators, peak flow variability or tests of bronchial hyperactivity can all be helpful although not necessarily conclusive. Failure to see an improvement after a bronchodilator has been given may not rule out asthma as bronchodilators don't always work in infants and young children. Although expiratory flow is reduced when airways obstruction is present, if this is measured between episodes of bronchospasm it may be normal.

Nonpharmacological treatment
When children are newly diagnosed with asthma, their parents are often anxious to know whether there are any dietary or environmental factors that can be changed or avoided to improve their child's condition. The reality is that this is extremely difficult to achieve, but measures to reduce house dust mite exposure may result in some benefit.(2) To be effective this may need to include the removal of carpets from the home, the treatment of soft furnishings with acaricides, dehumidification, changing or enclosing mattresses and bedding with impermeable barriers, the removal of soft toys from the bedroom and high-temperature washing of bedding.
A common issue is whether the presence of a pet dog or cat is causing or exacerbating the asthma. Expert opinion differs on this point, and while many would argue that the animal should be removed, observational studies have failed to demonstrate any benefit as a result of doing so. (3) Others would argue that the psychosocial benefits that a child experiences from owning a pet outweigh any benefits that arise from its removal.
Parents who smoke within the home should be strongly encouraged and helped to quit. Not only are they acting as poor role models for their children but there is irrefutable evidence that exposure to tobacco smoke exacerbates the severity of their child's condition. There is also some albeit limited evidence to show that if they quit, their child's asthma is likely to improve.

Pharmacological treatment
A stepped approach is usually adopted in the treatment of asthma and although the starting point for this is the use of a drug to provide symptomatic relief, in  reality the treatment should be tailored to the condition of the patient and the severity of their condition. It is also all too easy to forget that treatment can and should be stepped down as well as up whenever appropriate.
It is important to remember that in children, particularly those under five years of age, measurements of lung function give an unreliable guide to the severity or level of control of the condition.

Relievers
Short-acting ß-2 agonists such as salbutamol (Ventolin [Allen & Hanburys]) or terbutaline (Bricanyl [AstraZeneca]) are used for the immediate relief of asthma symptoms and are usually effective even in very small children. Although most effective when inhaled, oral preparations are available, which may occasionally be appropriate. When given orally, larger doses are usually necessary, which produce more side-effects such as tremor and tachycardia.
Antimuscarinic bronchodilators such as ipratropium (Atrovent [Boehringer Ing]) can produce short-term relief of symptoms in chronic asthma, but ß-2 agonists work more quickly and are generally preferred.
Theophylline (Uniphyllin [Napp]) is also a bronchodilator which is sometimes effective in children and may have an additive effect when given with ß-2 agonists. Variations in half-life between different preparations may be important and measurement of plasma concentrations necessary periodically. Children who need this sort of medication are likely to have more severe asthma and to be under the care of secondary care.

Preventers
For the majority of patients, inhaled corticosteroids such as beclometasone (Becotide [Allen & Hanburys]), budesonide (Pulmicort [AstraZeneca]) or fluticasone (Flixotide [Allen & Hanburys]) act to reduce airway inflammation and provide good control of asthma. To achieve their full effect, they must be used regularly, usually twice-daily, and begin to demonstrate an improvement after about three days of use. They do not produce the immediate improvement in symptoms that is seen with ß-2 agonists.
Parents are often worried when it is suggested that their child needs to be given "steroids" and if this issue is not addressed it may mean that treatment is not adhered to or at best is suboptimal. They should be reassured that although side-effects do occur from inhaled steroids, eg, reduced growth, these are quite rare. At the doses that are usually used they can be reassured that growth retardation is unlikely to be a problem and that their ultimate adult height will not be reduced. Notwithstanding this, the CSM does recommend monitoring of height and referral for specialist advice if the growth rate appears to be slowing. Recording growth velocity on a chart and showing parents how it compares to the predicted rate can help to reassure them that there is no problem. Growth can of course be restricted as a result of poor asthma control as well as from steroid side-effects.
Acute exacerbations of asthma sometimes need treatment with oral steroids. Unfortunately this may be unavoidable but lifesaving. The course of treatment should be as small and short as possible to minimise side-effects but adequate enough to treat the problem. Comprehensive advice about the use of steroids is included in the the BTS/SIGN guidelines.(4)
Sodium cromoglycate (Intal [Sanofi Aventis]) and nedocromil (Tilade [Sanofi Aventis]) are sometimes effective, particularly in allergic or exercise-induced asthma. Overall they probably don't work as well as corticosteroids, but they may be worth trying especially where parental anxiety about inhaled steroids cannot be overcome. The need to take them four times a day can make their use in children at school more difficult.(5)

Choice of inhaler
The choice of inhaler is always important, but this is particularly so in the case of children. No matter how good a device is in theory, if the child or their parents are unwilling or unable to us it, at best the treatment will be less than optimal and at worst may not be used at all. This is a situation where "cheapest" is not necessarily "best" and where one size definitely does not fit all.
In the case of infants there is little choice, but a metered-dose inhaler (MDI) with a spacer device and a mask delivers inhaled medication very efficiently and needs no coordination to use it. Parents should understand how well it works and how effective it can be if symptoms worsen. Although an electric nebuliser used in a GP surgery or hospital casualty appears more impressive and often prompts them to ask about buying one for home use, the reality is that an MDI and spacer work as well for most patients.

What to do when things go wrong
An acute asthma attack can be life-threatening and demands immediate treatment. It is impossible within this short article to provide a full guide to management of this emergency situation, but assessment of the severity of the problem should include checking for cyanosis and whether accessory muscles of respiration are being used as well as measurement of the pulse and respiratory rates. While wheezing is common it should be remembered that the silent chest in an ill child may also indicate a serious deterioration in their condition. An indication of severity can be gained if the child is unable to talk in full sentences while any reduction in conscious level should prompt an immediate call for emergency assistance.
In less serious circumstances the use of a nebuliser may improve the child's condition, but it should be remembered that on its own this is likely to be of limited value and without other changes in management the effects are likely to be short-lived.

Conclusion
Asthma is a common and complex problem that is well placed to be managed within primary care by nurses. In order to do so they must use many skills and tailor their approach to individuals and their families. Failure to do so will result in less than optimal care.

References
1. Lenney W. The burden of pediatric asthma. Med J Aust 1993;158:761-3.
2. Warner J. Controlling indoor allergens. Pediatr Allergy Immunol 2000;11:208-19.
3. Wood R, et al. The effect of cat removal on allergen content in household dust samples J Allergy Clin Immunol 1989;83:730-4.
4. Scottish Intercollegiate Guidelines Network and The British Thoracic Society. 2005 update to the British guideline on the management of asthma. SIGN and BTS. 2005.
5. Winnick S, et al. How do you improve compliance? Pediatrics 2005;115:718-24.