Dr Iain Small reviews key points from the BTS/SIGN guideline on the management of asthma, and in particular patient groups that require special consideration
  • The responsibility of managing asthma rests mainly in primary care
  • Confirming the presence of obstruction using spirometry is the gold standard for establishing a diagnosis of asthma
  • The aim of treatment for asthma is to achieve and maintain the highest level of disease control
  • Treatment of asthma should follow stepwise management as described in the BTS/SIGN guideline (see Figure 1, p.23)
  • Changes in treatment for asthma should only be considered after:
    • an assessment of patient adherence
    • identification and withdrawal of asthma triggers
    • assessment or correction of inhaler technique
  • Special consideration should be given to the following patient groups:
    • Adolescents
    • Pregnant women
    • People with occupational asthma
  • Patients who are acutely unwell with asthma should undergo detailed assessment.

Asthma is a common disease, and the UK leads the ways in terms of worldwide prevalence—it is estimated that 5.4 million people have asthma.1,2 The responsibility for diagnosing, treating, and reviewing these individuals rests with primary care. Only a small percentage of those with asthma require specialist intervention at the point of diagnosis or regular specialist involvement in review and treatment.

Evidence-based guidelines for asthma have been developed since the 1990s; initially they were produced independently by both the British Thoracic Society (BTS) and the Scottish Intercollegiate Guidelines Network (SIGN). These two organisations came together in 2003 to produce a combined national guideline on asthma. Unusually, this guideline is updated annually as part of a rolling programme, thus providing a ‘living guideline’, which takes into account new evidence and changes in clinical practice. 3

There are five key areas that are of greatest relevance to primary care and are fundamental to effective asthma management. These are:

  • establishing an accurate diagnosis
  • gaining control of asthma
  • treatment options
  • special circumstances (i.e. specific patient groups)
  • exacerbations.

Establishing an accurate diagnosis

Making a diagnosis of asthma is a clinical process. Although lung function, eosinophilia, exhaled nitric oxide, and other complex testing have their value, traditional clinical skills of history taking, examination, and treatment trials remain key aspects of diagnosing asthma. There are specific clinical indicators that increase the likelihood of an older child or adult having asthma. These are:3

  • characteristic symptom patterns of chest tightness and breathlessness with diurnal variation and response to triggers, such as exercise, cold air irritants, and allergens
  • personal history of atopy
  • family history of asthma
  • the presence of inspiratory and expiratory wheeze on auscultation
  • positive response to treatment with asthma medication.

In patients for whom the diagnosis of asthma is supported by the presence of two or more of the above indicators, it is reasonable to embark on a trial of inhaled asthma treatment.3 Confirming the presence of obstruction using spirometry is the gold standard for establishing an asthma diagnosis—this is defined as a ratio of forced expiratory volume in one second (FEV1): vital capacity (relaxed or forced, whichever is largest) of <0.7, which returns to normal following treatment. It may, however, be difficult to achieve this in clinical practice, particularly in children. Additionally, normal spirometry may still be evident in asthma due to the variable nature of the disease.

The time-honoured method of measuring the variability of peak expiratory flow (PEF) across a 2-week period is no longer recommended since the intrinsic variability of both the PEF meters themselves and of unsupervised patient recording, makes this method unreliable. Measurement of peak flow still has a valuable place in monitoring asthma and in establishing a diagnosis of occupational asthma.

Trials of asthma treatment should be comensurate with the level of severity of the patient’s symptoms; a clinical review of response is necessary in all cases. Such trials may involve the use of short-acting ?2-agonists (SABA), inhaled corticosteroids (ICS), or oral steroids. In children, it is helpful to follow a period of perceived treatment success (normally 8 weeks) with a period of treatment withdrawal in order to confirm that the improvement in symptoms is caused by the drug as opposed to normal symptom resolution following, for example, a viral infection.


Gaining asthma control

In common with its international counterparts, the BTS/SIGN guideline recommends that clinicians and patients should seek to achieve, and subsequently maintain, the highest levels of asthma control, which can be described as:3

  • no daytime symptoms
  • no night-time awakening due to asthma
  • no need for rescue medication
  • no exacerbations
  • no limitations on activity including exercise
  • normal lung function (in practical terms, FEV1 and/or PEF >80% predicted or best)
  • minimal side-effects from medication.

There are a range of patient-related outcome measures that can help healthcare professionals to assess asthma control. Perhaps the simplest is the Royal College of Physicians ‘Three Questions’, although others, such as the Asthma Control Test and Asthma Control Questionnaire, 3, 4 are more sensitive to a change in response to treatment over time.

Achieving control of asthma is not only important for the health of the patient in the short term, but may also result in better outcomes in the longer term, reducing airway remodelling and fixed-airflow obstruction. The different treatment steps for asthma are aimed at establishing, and then maintaining, this level of control, stepping up or down through the different levels according to response. 3 The treatment of asthma is a dynamic process, which is, of course, necessary for a variable disease.

Treatment options

Any treatment change for asthma should only be considered following:3

  • an assessment of patient adherence
  • the identification and withdrawal of asthma triggers
  • an assessment or correction of inhaler technique.

Non-pharmacological treatment options should be considered and may be helpful for some patients; those with proven effectiveness include weight reduction, house-dust-mite limitation, and breathing retraining (including, but not exclusively, the Buteyko method). 3

The stepwise management of adults is shown in Figure 1. Stepwise summaries for the management of asthma in children aged 5–12 years and below 5 years are also included in the guideline (see www.sign.ac.uk/guidelines/fulltext/101/index.html or www.brit-thoracic.org.uk/guidelines.aspx).

Pharmacological interventions differ between children and adults, specifically around the use of long-acting ?2-agonists (LABA), leukotriene receptor antagonists, and the recommended daily doses of ICS.3

Figure 1: Summary of stepwise management of asthma in adults3

graph

LABA=long-acting ?2 agonist; SR=sustained release
*Beclometasone dipropionate or equivalent
British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. SIGN 101. Edinburgh: SIGN, 2011 (updated 2012). Reproduced with kind permission. Available at: brit-thoracic.org.uk and sign.ac.uk


Special circumstances

The BTS/SIGN guideline also includes advice on managing asthma in specific patient groups. These are:3

  • adolescents
  • pregnant women
  • people with occupational asthma.

Adolescents

Adolescents are at significant risk from their asthma. The estimated prevalence of asthma in teenagers is 14%, of whom approximately 40% have severe asthma.8 In addition, it has been suggested that 20%–30% of teenagers with symptoms of asthma, remain undiagnosed.57 This is particularly the case for females, smokers, and those with difficult home circumstances. Adolescents with asthma, including those with perceived mild or moderate disease, are at greater risk of acute, severe, and life-threatening exacerbations.7 No differences have been observed in the smoking prevalence of young people with and without asthma.8

Specific areas that require additional attention for adolescents include:3

  • exercise
  • smoking
  • obesity
  • career and workplace choices
  • concordance with therapy
  • inhaler access at school
  • transition into adult services.

Pregnancy

Pregnancy often results in changes in asthma control, sometimes for the better, sometimes for the worse. The mechanisms by which this variation in outcome occurs are unknown.3 Treatment options remain the same in pregnant women as in those who are not pregnant, although, there is some evidence (mostly in animals) of an increased risk of cleft palate in children whose mothers were exposed to systemic steroids during pregnancy.9 Systemic (but not inhaled) steroids may also increase the risk of pre-term delivery.10 Concern about this should not override the clinical necessity for treatment when required; acute asthma in pregnancy is an emergency and should be managed in a hospital setting.3 Poor asthma control in pregnancy has been associated with intra-uterine growth retardation, although, labour in women with asthma does not result in significantly poorer outcomes (other than a higher Caesarian section rate).11

Occupational asthma

Adults with a new asthma diagnosis should be asked specific questions about their occupation in order to identify potential exposure, which may be the cause of 9%–15% of new cases in adults.3 People with potential occupational asthma should perform frequent (3–4 times daily) PEF monitoring, and preferably have periods of time away from work.3 From both a clinical and medico-legal point of view, all cases of potential occupational asthma should be referred to a specialist with an interest in this condition.3


Exacerbations

Exacerbations of asthma are an indication of poor asthma control and should be addressed as such. The guideline emphasises the importance of early access to treatment. Multiple doses of SABA should be used in the early stages of an attack. Assessment of acutely unwell patients should always include:3

  • respiratory rate
  • pulse
  • pulse oximetry
  • peak flow as a percentage of best ever measurement (or at least estimated for height, gender, and age)
  • cognitive function
  • respiratory effort and chest sounds
  • response to treatment.

Life-threatening asthma in adults is present when any one of the following is found:3

  • Altered consciousness
  • Exhaustion
  • Arrhythmia
  • Hypotension
  • Cyanosis
  • Silent chest
  • PEF <33% best/predicted
  • Blood oxygen saturation (SpO2) <92% on air
  • Arterial partial pressure of oxygen (PaO2) <8 kPa.

All patients with life-threatening asthma should be resuscitated, in accordance with the guideline recommendations, and admitted to hospital regardless of response to treatment.3

In children, the parameters for assessing acute asthma severity vary with age.It is good clinical practice to have the relevant reference ranges close at hand. SIGN has developed an ‘app’ for smart phones, which includes an abbreviated version of the BTS/SIGN guideline and contains emergency asthma assessment and treatment pages.12

An essential primary care toolkit for managing asthma emergencies would include:

  • copies of the BTS/SIGN guideline, with Annex 2 and 5
  • oxygen
  • nebulisation equipment (driven through oxygen)
  • SABA (either given as a pressurised metered dose inhaler or as a nebulised solution)
  • ipratropium nebuliser solution
  • prednisolone
  • hydrocortisone
  • peak-flow meter and predicted values for height, age, and gender
  • pulse oximeter.

Patients who experience acute episodes of asthma should be reviewed as soon as practically possible by the primary care team responsible for their care. This team should have received appropriate training for its role and have an ongoing professional development plan that includes regular asthma updates. Practices should consider holding an ‘at-risk’ register for patients who have sustained life-threatening episodes of asthma, bearing in mind that these events can also occur in patients with mild or moderate disease, or indeed, as a first asthma presentation.


Implementation

The potential barriers to implementing the BTS/SIGN guideline, in the author’s opinion, include:

  • workload, particularly in primary care
  • an impression that asthma is a straightforward and already well-managed condition
  • the limitations of the asthma targets in the quality and outcomes framework
  • patient factors such as concordance with therapy, unwillingness to attend for routine review, and complacency with their condition in the face of frequent symptoms and poor control.

Conclusion

In summary, asthma is the most common long-term condition of childhood and one of the most common conditions in adults.1 As such, the care and treatment of people with asthma form a substantial part of clinical activity in primary, secondary, and tertiary healthcare. The BTS/SIGN guideline on asthma provides a valuable, practical, and easy-to-follow set of evidence-based, clinician-written recommendations, which are available to help healthcare professionals and patients throughout the asthma pathway.3

Effective implementation of the guideline would, undoubtedly, reduce the impact of asthma on patients, clinicians, and the healthcare system.

  • With proper treatment, most cases of asthma can be managed in primary care, although prompt referral to specialist care when indicated is vital
  • CCGs should ensure that local primary care providers (including out-of‑ hours providers and walk-in centres) are aware of and follow the BTS/SIGN guideline, which can be found on online resources such as Map of Medicine
  • Retrospective audits of patients attending secondary care as a result of asthma exacerbations will often identify avoidable factors and help educate primary care
  • Such audits could be built into revalidation and Care Quality Commission assurance programmess for practices and could be coordinated by the CCG
  • Local formularies should identify cost-effective preparations for asthma therapies, but allow a choice of inhaler type to meet personal preference and aid compliance
  • Tariff costs:a
    • Respiratory medicine outpatient = £223 (new), £105 (follow up)
    • Asthma emergency admission = (DZ15F) £642.
  1. Asthma UK website. Facts for journalists. Available at: www.asthma.org.uk/news-centre/facts-for-journalists/ (accessed 19 June 2012).
  2. Braman S. Global burden of asthma. Chest 2006; 130 (1 Suppl): 4S–12S.
  3. British Thoracic Society, Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. SIGN 101. Edinburgh: SIGN, 2011 (revised January 2012). Available at: www.brit-thoracic.org.uk/Portals/0/Guidelines/AsthmaGuidelines/sign101%20Jan%202012.pdf
  4. Pearson M, Bucknall C. Asthma care. Thorax 2000; 55 (6): 535.
  5. Siersted H, Boldsen J, Hansen H et al. Population based study of risk factors for underdiagnosis of asthma in adolescence: Odense schoolchild study. BMJ 1998; 316 (7132): 651–657.
  6. Yeatts K, Shy C. Prevalence and consequences of asthma and wheezing in African-American and White adolescents. J Adolesc Health 2001; 29 (5): 314–319.
  7. Yeatts K, Davis K, Sotir M et al. Who gets diagnosed with asthma? Frequent wheeze among adolescents with and without a diagnosis of asthma. Pediatrics 2003; 111 (5 Pt 1): 1046–1054.
  8. Action on Smoking and Health. Asthma and smoking. London: ASH, 2007. Available at: ash.org.uk/files/documents/ASH_595.pdf
  9. Kallen B. Maternal drug use and infant cleft lip/palate with special reference to corticoids. Cleft Palate Craniofac J 2003; 40 (6): 624–628.
  10. Kallen B, Rydhstroem H, Aberg A. Asthma during pregnancy—a population based study. Eur J Epidemiol 2000; 16 (2): 167–171.
  11. Bakhireva L, Schatz M, Lyons Jones K, Chambers C. Asthma control during pregnancy and the risk of preterm delivery or impaired fetal growth. Ann Allergy Asthma Immunol 2008; 101 (2): 137–143.
  12. Scottish Intercollegiate Guidelines Network website. SIGN app. Available at: www.sign.ac.uk/guidelines/apps/index.html (accessed 19 June 2012). G