Canadian Thoracic Society 2012 guideline update: diagnosis and management of asthma in preschoolers, children and adults

Abstract

Background: In 2010, the Canadian Thoracic Society (CTS) published a Consensus Summary for the diagnosis and management of asthma in children six years of age and older, and adults, including an updated Asthma Management Continuum. The CTS Asthma Clinical Assembly subsequently began a formal clinical practice guideline update process, focusing, in this first iteration, on topics of controversy and⁄or gaps in the previous guidelines.

Methods: Four clinical questions were identified as a focus for the updated guideline: the role of noninvasive measurements of airway inflammation for the adjustment of anti-inflammatory therapy; the initiation of adjunct therapy to inhaled corticosteroids (ICS) for uncontrolled asthma; the role of a single inhaler of an ICS⁄long-acting beta(2)-agonist combination as a reliever, and as a reliever and a controller; and the escalation of controller medication for acute loss of asthma control as part of a self-management action plan. The expert panel followed an adaptation process to identify and appraise existing guidelines on the specified topics. In addition, literature searches were performed to identify relevant systematic reviews and randomized controlled trials. The panel formally assessed and graded the evidence, and made 34 recommendations.

Results: The updated guideline recommendations outline a role for inclusion of assessment of sputum eosinophils, in addition to standard measures of asthma control, to guide adjustment of controller therapy in adults with moderate to severe asthma. Appraisal of the evidence regarding which adjunct controller therapy to add to ICS and at what ICS dose to begin adjunct therapy in children and adults with poor asthma control supported the 2010 CTS Consensus Summary recommendations. New recommendations for the adjustment of controller medication within written action plans are provided. Finally, priority areas for future research were identified.

Conclusions: The present clinical practice guideline is the first update of the CTS Asthma Guidelines following the Canadian Respiratory Guidelines Committee's new guideline development process. Tools and strategies to support guideline implementation will be developed and the CTS will continue to regularly provide updates reflecting new evidence.

Figures

Figure 1)

Pooled OR of patients experiencing one or more exacerbations requiring systemic glucocorticoids, comparing maintenance inhaled corticosteroid (ICS) dose to increased ICS dose during exacerbations and analysed by intention-to-treat. Trials are stratified according to the fold-increase in ICS dose from baseline at the onset of exacerbation (double dose versus quadruple dose). The width of the horizontal line represents the 95% CI around the point estimate (black square). The size of the point estimate represents the relative weight (% weight) of each trial in the pooled summary estimate (diamond). The vertical line is the line of no effect (OR=1.0). © Cochrane Collaboration. Figure reproduced with permission from the authors and publisher

Figure 2)

Pooled OR of patients experiencing one or more exacerbations requiring systemic glucocorticoids, comparing maintenance inhaled corticosteroid (ICS) dose to increased ICS dose during exacerbations; this subgroup analysis focuses only on patients who used the study drug at least once (35% of participants) during the study period. Trials are stratified according to the fold-increase in ICS dose from baseline at the onset of exacerbation (double dose versus quadruple dose). The width of the horizontal line represents the 95% CI around the point estimate (black square). The size of the point estimate represents the relative weight (% weight) of each trial in the pooled summary estimate. The vertical line is the line of no effect (OR=1.0). © Cochrane Collaboration. Figure reproduced with permission from the authors and publisher

Figure 3)

Management hinges on confirming the diagnosis. All individuals with confirmed asthma should receive self-management education, including a written action plan. Very mild intermittent asthma may be treated with a short-acting beta2-agonist (SABA) taken as needed. SABAs are recommended for relief of symptoms; individuals 12 years of age and over with moderate to severe asthma (particularly those who are exacerbation prone and have poor control) who are taking an ICS/LABA formulation approved also for use as a reliever may do so. Inhaled corticosteroids (ICS) should be introduced early as the initial maintenance treatment for asthma even in individuals who report asthma symptoms less than three times a week. LTRA are second-line monotherapy for mild asthma. If asthma is not adequately controlled by low doses of inhaled corticosteroids, additional therapy should be considered. In children 6 years of age and over, the ICS should be increased to a medium dose before adding an adjunct agent such as a long-acting beta2-agonist (LABA) or LTRA. In children 12 years of age and over and adults, a LABA should be considered first as adjunct therapy. A LABA should only be used in combination with an ICS. Increasing to a medium dose of ICS or the addition of an LTRA are third-line therapeutic options. Theophylline may be considered as a fourth-line agent in adults. Severely uncontrolled asthma may require additional treatment with prednisone. Omalizumab may be considered in individuals 12 years of age and over with atopic asthma poorly controlled despite high doses of ICS and appropriate add-on therapy, with or without prednisone. Asthma symptom control and lung function tests, inhaler technique, adherence to asthma treatment, exposure to asthma triggers in the environment, and the presence of co-mordibities should be reassessed at each visit and before altering the maintenance therapy. Consider also assessment of sputum eosinophils in adults with uncontrolled moderate to severe asthma managed in specialialized centres. After achieving acceptable asthma control for at least a few weeks to months, the medication should be reduced to the minimum necessary dose to achieve adequate asthma control and prevent future risk of exacerbations. HFA: Hydrofluoroalkane; IgE: Immunoglobulin E; mcg: Micrograms; PEF: Peak expiratory flow; yrs: Years