This site is intended for health professionals only

Asthma inhalers in children: what are the options?

Charles Broomhead
MB ChB MRCGP DA DRCOG
GP and GP Trainer
Sutton Coldfield
Honorary Clinical Lecturer
Birmingham Medical School
E:charles.broomhead@lineone.net

Where are we going wrong with asthma management? Is it simply that our patients aren't listening to our advice, or are there other reasons for our lack of success?
Treating most conditions is a complex process that involves an interactive relationship between the patient and his caregiver. The situation becomes even more complicated when the patient is a child or adolescent with a chronic condition such as asthma. Consultations generally involve at least one member, and sometimes additional members, of the family group. Moreover, this is not a static situation. The dynamics of the relationship change as the child gets older and is better able to express and impose their own views and wishes about the way in which they are treated.

Diagnosis
As in any condition, correct diagnosis is fundamental to effective treatment. In an older patient we might look for the classic symptoms of cough, shortness of breath and wheezing occurring simultaneously. Unfortunately, it is not uncommon for patients, particularly children, to present with only some of these, or perhaps other symptoms altogether. The child who has a chronic cough, often just at night or when they exercise, is a typical example of this. The aphorism that "all that wheezes isn't asthma and all asthmatics don't wheeze" is one that is important to remember.
All of the previously mentioned symptoms can occur in other respiratory diseases and are usually considered to be too nonspecific to allow a definitive diagnosis. Crucially, other possibilities such as the aspiration of a foreign body, cystic fibrosis and respiratory infections must not be forgotten. Corroborating evidence to support a diagnosis of asthma must be sought. This will include a family history of the disease, physical ­examination, and ideally measurements such as peak expiratory flow rate (PEFR).
PEFR measurement is highly dependent upon technique, and many people find it difficult to perform. In very small children it is impossible, and a therapeutic trial of medication may be necessary to confirm the diagnosis.

Education
One of the most important requirements if optimal control is to be achieved is education of the patient or, particularly in the case of a child, the parent or other caregiver. This process will be greatly enhanced, and compliance with treatment improved, if a trusting relationship can be established between these individuals and the health professional who is treating them. The actual rate of noncompliance of children with asthma medication is difficult to calculate, but Creer et al suggested an overall compliance rate of 48% in a review of 10 studies of paediatric asthma medication adherence.(2)
In the case of small children and infants, parents play a critical role in the management of this disease. They will be responsible for administering medication and must understand the rationale for doing so. Unresolved fears about the treatment, such as whether an inhaled steroid is safe, must be addressed and dispelled at the earliest opportunity. Repetition of this process and reinforcement should occur frequently as part of an ongoing educational process. Other adults, such as childminders, nursery nurses and teachers, will also play an important part in treating children with asthma, and ways need to be found to ensure that they are willing and competent to do so. In many instances this will simply require explanation by the child's parent, but more complex barriers may exist. Schools may have specific issues relating to the use of medication and may need assistance in overcoming these. Certainly a written treatment plan is highly desirable.
As the child becomes older they will gradually assume responsibility for managing their own condition and the parents' influence will wane. As those of us who have had children of our own know, image and conformity to peer-group behaviour is a fundamental characteristic of growing up. Inhaled medication is critical to the management of asthma, and failure to recognise and incorporate the child's views into issues such as choice of inhaler is to significantly reduce the chance that they will take their medication appropriately.

Selection of drug and inhaler device
The management of asthma is based on two groups of medication, namely those that are designed to relieve symptoms and those that are intended to prevent them. The inhaled route of administration is generally preferred as it permits medication to be delivered close to its site of action, allowing a smaller dose to be used and causing less systemic side-effects.
Short-acting b(2)-agonists such as salbutamol and terbutaline are almost identical in terms of their efficacy and are the most commonly used relief medications. In general, they provide the foundation upon which subsequent treatment plans are based. In an ideal world, if asthma is well controlled, their use will be minimal. In reality, we know that it is this group of drugs that many patients rely on and use inappropriately to manage their condition.
Inhaled corticosteroids (beclometasone, budesonide, fluticasone) are commonly used as preventive therapy, while long-acting b(2)-agonists (salmeterol, formoterol) are finding increasing favour as their therapeutic advantages are recognised, namely their steroid-sparing potential and the opportunities that they offer in terms of better symptom control. The choices surrounding these drugs are more complex as their pharmacokinetic characteristics differ considerably. In the main they can be administered twice daily, usually at home, so the requirements for their delivery system differ from those of portable relief medication.  Sodium cromoglycate is an exception to this general rule, as it is a prophylactic medication that must be administered at least four times a day.

What is the best inhaler to use?
The ideal delivery system depends on the patient, the medication used and the clinical situation. Options include a nebuliser, pressurised metered-dose inhaler (MDI) or dry powder device. There is huge potential for variability in the amount of drug that reaches the peripheral airways, estimates ranging from between 6% and 60%.(3) This is not a situation where "one size fits all", and the device that is chosen needs to fulfil a range of basic criteria: critically, it must match the needs of the patient and deliver an appropriate dose of medication to the lungs. It should also cause minimal oropharyngeal deposition, while ease of use and cost-effectiveness remain important considerations.

Nebulisers or metered-dose inhalers?
Unfortunately, many parents' first experience of their child's asthma is when emergency treatment is needed. The drama of an urgent trip to the surgery or casualty, perhaps followed by hospital admission, is not easily forgotten. When this is associated with highly effective treatment with a nebuliser, it is easy to understand why they may view this as the "gold standard". The reality is, of course, that, except in unusual circumstances, nebulised therapy is unnecessary and much simpler solutions are needed. An MDI used with a spacer device and facemask is usually the optimal choice for babies and very small children. Not only can it produce lung deposition rates that are similar to a nebuliser, but it is also very inexpensive.

Metered-dose or dry powder inhalers?
In older children and adults the MDI and spacer remains the theoretical best choice for prophylactic treatment, but in reality there are many other factors to take into consideration. Other delivery devices are certainly needed for rescue medication, the physical size of spacers making them difficult to use away from home.
MDIs without a spacer are notoriously difficult to use and need a great deal of coordination on the part of the user. Used well they are a cost-effective way of taking inhaled medication, but more frequently their use results in very little medication reaching the lungs. As a consequence of this, control is poor and side-effects such as oral thrush are often seen.
Breath-actuated MDIs and dry powder devices address some of these problems and are generally easier to use. They may also have other advantages, such as indicators to show when the medication will run out. Although there are other considerations such as whether inspiratory flow is great enough to activate the device, unfortunately they are generally more expensive, and this is often viewed as the main barrier to their use.
Some of the most expensive medications that we use are the ones that the patient can't or won't use, and inhalers are no exception to this rule. Device choice must focus on the patient's ability and willingness to use it. This is particularly so in children, when factors such as the shape, colour or size of an inhaler may determine whether or not they take their medication. While their parent's concerns may relate to the side-effects of the medication, the child's is more likely to be whether they will appear "uncool"!

Summary
Good control of asthma is not just dependent on making the diagnosis and prescribing the right medication. Particularly in children, choice of delivery device is crucial if optimal control is to be achieved.

[[nip21_box1_20]]

[[nip21_box1_21]]

References

  1. Gruffyd Jones K, Bell J, Fehrenbach C, et al. Understanding patients' perceptions of asthma: results of the asthma control and expectations (ACE) survey. Int J Clin Pract 2002;53:89-93.
  2. Creer T, Wigal J. Self-efficacy. Chest 1993;103;1316-17.
  3. Le Souef P. The meaning of lung dose. Allergy 1999;54 Suppl 49:93.

Resources
British Thoracic Society
W:www.brit-thoracic.org.uk
Provides a wealth of advice and guidelines for the management of asthma and other respiratory diseases
General Practice Airways Group
W:www.gpiag.orgProvides practical advice, ­information and opportunities for education about respiratory diseases
Prodigy
W:www.prodigy.nhs.uk
A source of up-to- date evidence- based clinical knowledge about asthma
Clinical Evidence from the BMJ Publishing Group
W:http://clinical evidence.com
An international source of the best available evidence for effective healthcare. It summarises what is known about many conditions, including asthma.