Dr Malcolm Campbell says GPs should look for clinical features of asthma in their patients, and implement a stepped care approach

The asthma guidelines from BTS in 1990 and SIGN in 1996 both achieved widespread recognition and acceptance. When the two were combined in a revised version in 2003, the resulting BTS/SIGN guideline became one of the most recognised and implemented pieces of guidance in the UK.

Annual partial updates have been produced since initial publication of the guideline and a completely revised version has now been launched. The development of the 2008 version of the BTS/SIGN British guideline on the management of asthma involved some of the foremost names in UK asthma care.1

The 2008 asthma guideline contains rewritten sections on diagnosis in adults and children, and updated sections on management, patient education, and the organisation of care.

There is also new advice on audit of asthma care. Regular updates are promised that will be posted on the BTS and SIGN websites. This article highlights the major changes in the 2008 guideline.

Content of the guideline

Guidelines are most effective where there is a solid evidence base and a clear concept of the best approach to diagnosis and management. In the case of asthma, a guideline should answer questions on:

  • diagnosis
  • monitoring
  • treating stable asthma
  • treating acute exacerbations
  • helping patients to manage their asthma
  • auditing the care provided.

Diagnosis

The guideline emphasis for diagnosis in both adults and children is now very firmly on clinical features. Asthma should be considered a probable diagnosis when the patient has variable airflow obstruction accompanied by more than one recurrent symptom of:

  • wheeze
  • breathlessness
  • chest tightness
  • cough.

Spirometry is recommended as the best measure of airflow obstruction, although the sensitivity of a positive spirometric response to a trial of inhaled steroids may be as low as 24%. However, if spirometry results are normal on testing, particularly if the child is asymptomatic at the time of the test, this does not rule out a diagnosis of asthma. Other respiratory diseases may cause abnormal results in children.

The guideline recommends that the probability of asthma is classed as:

  • high—diagnosis of asthma likely
  • intermediate—diagnosis uncertain
  • low—diagnosis other than asthma likely.

If the probability is high, a trial of treatment for probable asthma is recommended, with the use of spirometry to attempt to confirm the diagnosis and monitor the response to treatment.

Monitoring

The guideline suggests that symptom-based monitoring, using a validated tool, is the best approach to long-term care. For overall monitoring, the following should be checked regularly:1

  • symptoms using the Royal College of Physicians three questions,2 the Asthma Control Questionnaire, or Asthma Control Test
  • lung function assessment by spirometry or peak expiratory flow
  • exacerbations, oral steroid use, time off work or school since last assessment
  • inhaler technique
  • treatment compliance, measured by prescription refill frequency
  • bronchodilator use, measured by prescription refill frequency
  • possession and use of a self-management plan.

Prevention

The guideline is unable to recommend any prevention strategies. Avoiding exposure to allergens, such as house dust mite, does not seem to prevent the development of asthma, nor significantly reduce symptoms in patients with asthma. Inhaled steroids and ?2 agonists remain the mainstay of treatment for chronic stable asthma, and there is no evidence that alternative or complementary therapies such as homeopathy and acupuncture are effective.

Pharmacological treatment

The main change to the recommendations on pharmacology in the revised BTS/SIGN guideline is to reflect the increasing certainty about the optimum dose of inhaled steroid that can be administered before adding in a long-acting ?2 agonist (LABA) as the best option at Step 3. In accordance with the review findings of the Medicines and Healthcare products Regulatory Agency, the guideline development group agreed that LABAs are safe as long as they are used in conjunction with inhaled corticosteroids.

Stepped care

The guideline continues to recommend a stepwise approach to management, with variable doses being given in accordance with the age of the patient (children under 5 years, children 5–12 years, or adults). The stepwise management comprises:1

  • Step 1: mild intermittent asthma
  • Step 2: regular preventer therapy
  • Step 3: initial add-on therapy
  • Step 4: persistent poor control
  • Step 5: continuous or frequent use of oral steroids (for children >5 years of age and adults).

Long-term use of oral steroids can lead to systemic side-effects; these may include raised blood pressure and adverse effects on bone density. Patients should be monitored carefully for changes.

Once symptoms have been controlled, asthma treatments should be stepped down to the lowest effective dose.

Treatment of exacerbations

Oral steroids remain the mainstay in the treatment of significant exacerbations. The previously recommended practice of doubling up the dose of inhaled steroid has been shown to be ineffective. Increasing the dose fivefold for patients on low-dose inhaled steroids (200 ?g) has been shown to be effective. However, this is not a guideline recommendation and it says further research is needed and this increased dose should not be extrapolated for use in patients already taking high-dose steroids.

The initial treatment for acute exacerbations should be high-dose inhaled ?2 agonists. Oral steroids should be considered for patients with an acute asthma attack and peak expiratory flow less than 75% of previous best. For patients with acute severe asthma and peak expiratory flow less than 50% of previous best, immediate admission should be considered.

Personal action plans

The guideline recommends that all patients, but particularly those with a history of previous hospital admissions, should have a personal action plan. The plan should include:

  • action based on symptoms or the individual’s peak expiratory flow
  • two to three action points
  • individualised instructions on when to start oral steroids.

Audit and the organisation of care

The guideline recommends read coding of patients when the diagnosis is made or as they join the practice, which will provide a meaningful database to enable auditing the percentage of asthma patients being reviewed annually. Most of the recommendations fit within the current scope of the Quality and Outcomes Framework.3 The guideline also contains useful suggestions for auditing the effectiveness of asthma management.

Summary

Unfortunately, although a great deal of research has been done since the original guideline was issued in 2003, the result has been to create greater uncertainty in places, with the result that the new guideline does not offer the clear recommendations in all areas of the earlier versions. It is not entirely clear when oral steroids should be used in an exacerbation and there is no advice on what to do in a less severe exacerbation. As the guideline becomes increasingly evidence based, it is developing the characteristic familiar to many of us: ‘The more I know the less certain I become’.

However, the revised BTS/SIGN British guideline on the management of asthma contains useful sections on ‘difficult asthma’ and a helpful analysis of asthma deaths. The role of complementary and alternative therapies is dealt with firmly but fairly. Overall, although less definite in its recommendations, this updated guideline will prove helpful to healthcare practitioners dealing with patients with asthma.

  1. British Thoracic Society, Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. SIGN: Edinburgh, 2008.
  2. Pearson M, Bucknall C, editors. Managing clinical outcome in asthma: a patient-focused approach. London: RCP, 1999.
  3. British Medical Association. www.bma.org.uk/ap.nsf/Content/focusQOF0308G