The SIGN/BTS joint guideline provides up to date evidence-based recommendations on all aspects of asthma management, explains Dr John Haughney

Throughout the 1990s, both the British Thoracic Society and SIGN produced various guidelines on the management of asthma (Box 1, below). Recognising the need to update their respective guidelines using evidence-based methodology, and taking into account the scale of the task involved and the wish to avoid potential duplication of effort, BTS and SIGN agreed to produce a new comprehensive joint British guideline.

The new guideline would be strengthened through collaboration with the National Asthma Campaign, the RCP, the General Practice Airways Group, the Royal College of Paediatrics and Child Health and the British Association of Accident and Emergency Medicine.

The joint guideline was developed using SIGN methodology,8 adapted for UK-wide development, and uses the SIGN system for the grading of recommendations.9 Initial literature searches based on key questions produced more than 15 000 abstracts, and all relevant papers published up until the end of September 2001 have been considered within this review.

A multidisciplinary steering group was established to oversee the development of the guideline, and the task of reviewing the evidence was divided between nine individual multidisciplinary evidence review groups.

In line with SIGN guideline development methodology, a national open meeting was held at which the guideline development group presented their draft recommendations for consultation. The draft was also available on the SIGN and BTS websites, to allow those unable to attend the meeting to contribute. An extensive panel of peer reviewers has also reviewed the guideline.

The guideline provides a comprehensive source of evidence-based recommendations and advice on a range of aspects of asthma care. These include diagnosis and natural history, nonpharmacological management, Pharmacological management, inhaler devices, management of acute asthma, asthma in pregnancy, occupational asthma, organisation and delivery of care, education and self-management, concordance and compliance, and outcomes and audit.

Box 1: Chronology of asthma guideline development
1990 Guidelines for the management of chronic persistent asthma in adults and acute severe asthma. Joint initiatives between the British Thoracic Society, the Royal College of Physicians of London, the KingÍs Fund Centre, and the National Asthma Campaign.1,2
1993 Updated to include childhood asthma. Also involved the British Paediatric Association, the RCGP, the General Practitioners in Asthma Group, the British Association of Accident and Emergency Medicine and the British Paediatric Respiratory Group.3
1995 Guidelines further updated.4
1996 SIGN guideline on the hospital inpatient management of acute asthma attacks.5
1998 SIGN guideline on the primary care management of asthma.6
1999 SIGN guideline on the management of acute asthma.7

Key messages

Diagnosis and natural history

  • Objective tests should be used to try to confirm a diagnosis of asthma before long-term therapy is started
  • The criteria on which the diagnosis has been made should be recorded
  • Failure to respond to asthma treatment should prompt a search for an alternative, or additional, diagnosis.

Figure 1 (below) describes the factors to consider when diagnosing asthma in adults.

Figure 1: Diagnosis of asthma in adults
Consider the diagnosis of asthma in patients with some or all of the following
Symptoms (episodic/variable): Signs:
  • Wheeze
  • Shortness of breath
  • Chest tightness
  • Cough
  • None (common)
  • Wheeze - diffuse, bilateral, expiratory (± inspiratory)
  • Tachypnoea
Helpful additional information
  • Personal or family history of asthma or atopy (eczema, allergic rhinitis)
  • History of worsening after use of aspirin/NSAID ingestion, use of beta blockers (including glaucoma drops)
  • Recognised triggers - pollens, dust, animals, exercise, viral infections, chemicals, irritants
  • Pattern and severity of symptoms and exacerbations
Objective measurements
  • >20% diurnal variation on >=3 days in a week for 2 weeks on PEF diary or FEV1 >=15% (and 200ml) increase after short acting beta2 agonist (e.g. salbutamol 400µg by pMDI + spacer or 2.5mg by nebuliser) or FEV1 >=15% (and 200ml) increase after trial of steroid tablets (prednisolone 30mg/day for 14 days) or FEV1 >=15% decrease after 6 minutes of exercise (running)
  • Histamine or methacholine challenge in difficult cases
Indications for referral for specialist opinion/further investigation* Differential diagnoses include:
  • Diagnosis unclear or in doubt
  • Unexpected clinical findings e.g. crackles, clubbing, cyanosis, heart failure
  • Spirometry or PEFs donÍt fit the clinical picture
  • Suspected occupational asthma
  • Persistent shortness of breath (not episodic, or without associated wheeze)
  • Unilateral or fixed wheeze
  • Stridor
  • Persistent chest pain or atypical features
  • Weight loss
  • Persistent cough and/or sputum production
  • Non-resolving pneumonia

* Consider chest X-ray in any patient presenting atypically or with additional symptoms

  • COPD
  • Cardiac disease
  • Tumour
  • Laryngeal
  • Tracheal
  • Lung
  • Bronchiectasis
  • Foreign body
  • Interstitial lung disease
  • Pulmonary emboli
  • Aspiration
  • Vocal cord dysfunction
  • Hyperventilation

Nonpharmacological management

  • Primary and secondary allergen avoidance are of unknown benefit
  • No recommendations on complementary medicines can be made on the current evidence
  • Immunotherapy is effective but its clinical role remains unclear.

Pharmacological management

  • Start patients at a dose of inhaled corticosteroids appropriate to the severity of the disease
  • Titrate the dose of inhaled corticosteroids to the lowest dose at which effective control of asthma is maintained
  • Carry out a trial of other treatments (such as long acting beta2 agonists) before increasing the inhaled corticosteroid dose above 800 micrograms per day for adults or 400 micrograms per day for children
  • The first choice of add-on therapy to inhaled steroids in adults and children (5-12 years) is an inhaled long acting beta2 agonist
  • Monitor childrenÍs height regularly.

Inhaler devices

  • Prescribe inhalers only after patients have received training in the use of the device and have demonstrated satisfactory technique
  • The best device is one the patient can use effectively.

Management of acute asthma

  • Health professionals must be aware that patients with severe asthma and one or more adverse psychosocial factors are at risk of death
  • Objective assessment of acute asthma is essential (heart and respiratory rate, peak flow as a percentage of the patientÍs best or predicted and oxygen saturation, if available). It may be helpful to use a systematic recording process
  • A pressurised metered-dose inhaler and large volume spacer are an effective alternative to a nebuliser in mild to moderate acute asthma
  • In severe asthma and asthma that is poorly responsive to an initial bolus dose of a beta2 agonist, consider continuous nebulisation
  • Give systemic steroids in adequate doses in all cases of acute severe asthma
  • Intravenous magnesium is effective by slow injection but more studies are needed in the UK
  • Antibiotics are not an effective treatment for acute asthma.
  • Figures 2a, b and 3a, b (below) show pp. 10-13 of the Quick Reference Guide, describing the management of acute asthma in adults and children.
Figure 2a: Page 10 of the Quick Reference Guide showing the management of acute asthma in adults
© Scottish Intercollegiate Guidelines Network and The British Thoracic Society 2003
Figure 2b: Page 11 of the Quick Reference Guide showing the management of acute asthma in adults
© Scottish Intercollegiate Guidelines Network and The British Thoracic Society 2003
Figure 3a: Page 12 of the Quick Reference Guide showing the management of acute asthma in children
© Scottish Intercollegiate Guidelines Network and The British Thoracic Society 2003
Figure 3b: Page 13 of the Quick Reference Guide showing the management of acute asthma in children
© Scottish Intercollegiate Guidelines Network and The British Thoracic Society 2003

Asthma in pregnancy

  • In general, the medicines used to treat asthma are safe to use in pregnancy
  • Use beta2 agonists, inhaled steroids and oral steroids as normal in pregnancy
  • Encourage breast-feeding as it may have a protective effect against wheezing in early life.

Organisation and delivery of care

  • Clinical review should be structured and should use a standard recording system, for example the RCPÍs three questions (Box 2, below)
  • Asthma control should be assessed against the following standards:
  • Minimal day- and night-time symptoms
  • Minimal need for reliever medication
  • No exacerbations
  • No limitations on physical activity
  • Normal lung function (FEV1and/or PEF >80% of best or predicted)
  • In primary care, patients with asthma should be reviewed regularly by a nurse trained in asthma management
Box 2: The three RCP questions for use in clinical review*
In the last week or month:
  • Have you had difficulty sleeping because of your asthma symptoms (including cough)?
  • Have you had your usual asthma symptoms during the day (cough, wheeze, chest tightness or breathlessness)?
  • Has your asthma interfered with your usual activities (e.g. housework, work, school etc)?
* Applies to all patients with asthma aged 16 years and over. Use only after diagnosis has been established

Education and self-management

  • Offer education in self-management, including written asthma action plans focusing on individual needs, to all patients with asthma, particularly those admitted to hospital
  • Patient education and simple written action plans can reduce admissions, GP attendances and morbidity in adults and children
  • Every asthma consultation is an opportunity to review, reinforce and extend both knowledge and skills.

Audit

  • Guidelines alone do not affect clinical practice. Feedback based on audit is, therefore, useful, both as part of an implementation strategy and for longer term positive influence on practice.

Further research

In response to demand from patients who are clearly interested in nonpharmacological treatments for asthma, the guideline includes a section that reviews the evidence on a variety of complementary therapies. While the evidence was not sufficiently strong to support any clinical recommendations in this area it is clear that further research is required to provide a greater number of high quality studies and, in turn, more conclusive evidence.

The gaps in our knowledge do not, however, appear only in less established areas of research, such as complementary medicine, and may be surprising to some readers.

Our review of the literature confirmed that we still do not know the threshold at which inhaled steroids should be introduced, despite the plethora of pharmacological studies on asthma; nor do we have any evidence to provide guidance as to which treatment strategy should be tried first at step 4 (persistent poor control) of the stepwise management approach.

Further targeted research, directed at gaps in our knowledge highlighted by an extensive review of the literature such as this, will improve our understanding of asthma and should, in time, lead to more grade A recommendations.

Conclusion

The new joint guideline provides a comprehensive source of guidance, based upon a review of the latest available evidence, for all health professionals involved in the clinical management of asthma. We are confident that implementation of the guidelineÍs recommendations in practice will significantly improve asthma care for patients throughout the United Kingdom.

British Guideline on the Management of Asthma: a national clinical guideline, is published by the Scottish Intercollegiate Guidelines Network and The British Thoracic Society as a supplement to Thorax, Vol 58 (Suppl 1) and can also be downloaded from the SIGN website: www.sign.ac.uk

References

  1. Guidelines for the management of asthma in adults: I - Chronic persistent asthma. Statement by the British Thoracic Society, Research Unit of the Royal College of Physicians of London, KingÍs Fund Centre, National Asthma Campaign. Br Med J 1990; 301: 651-3.
  2. Guidelines for the management of asthma in adults: II - Acute severe asthma. Statement by the British Thoracic Society, Research Unit of the Royal College of Physicians of London, KingÍs Fund Centre, National Asthma Campaign. Br Med J 1990; 301: 797-800.
  3. Guidelines on the management of asthma. Statement by the British Thoracic Society, the British Paediatric Association, the Research Unit of the Royal College of Physicians of London, the KingÍs Fund Centre, the National Asthma Campaign, the Royal College of General Practitioners, the General Practitioners in Asthma Group, the British Association of Accident and Emergency Medicine, and the British Paediatric Respiratory Group. Thorax 1993; 48(Suppl 2): S1-24.
  4. British Thoracic Society, National Asthma Campaign, Royal College of Physicians of London in association with the General Practitioners in Asthma Group, et al. The British guidelines on asthma management 1995 review and position statement. Thorax 1997; 52(Suppl 1): S1-S21.
  5. Scottish Intercollegiate Guidelines Network. SIGN 6: Hospital inpatient management of acute asthma attacks. Edinburgh: SIGN, 1996.
  6. Scottish Intercollegiate Guidelines Network. SIGN 33: Primary care management of asthma. Edinburgh: SIGN, 1998.
  7. Scottish Intercollegiate Guidelines Network. SIGN 38: Emergency management of acute asthma. Edinburgh: SIGN, 1999.
  8. Scottish Intercollegiate Guidelines Network. SIGN 50: A Guideline DevelopersÍ Handbook. Edinburgh: SIGN, 2002.
  9. Harbour R, Miller J. A new system for grading recommendations in evidence based guidelines. Br Med J 2001; 323: 334-6.

 

Guidelines in Practice, February 2003, Volume 6(2)
© 2003 MGP Ltd
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