Airway obstruction at time of symptoms prompting use of reliever therapy in children with asthma

Association of symptom control with changes in lung function, bronchial hyperresponsiveness, and exhaled nitric oxide after inhaled corticosteroid treatment in children with asthma

BACKGROUND

A key therapeutic approach to asthma, which is characterized by chronic airway inflammation, is inhaled corticosteroid (ICS). This study evaluated the association of symptom control with changes in lung function, bronchial hyperresponsiveness (BHR), and exhaled nitric oxide (eNO) after ICS treatment in asthmatic children.

METHODS

A total of 33 children aged between 5 and 12 years with mild to moderate persistent asthma were treated with 160 μg ciclesonide per day for 3 months. At days 0 and 90, the following parameters were assessed: asthma symptom scores; lung function, including forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and forced expiratory flow at 25-75% of forced vital capacity (FEF_25-75%); BHR to methacholine and adenosine 5-monophosphate (AMP); and eNO.

RESULTS

Asthma symptom scores, lung function parameters, BHR to methacholine and AMP, and eNO levels at day 90 were significantly improved versus day 0 (all p < 0.001). Symptom scores at day 90 were not correlated with changes in lung function and BHR to methacholine during the follow-up period, whereas those at day 90 were more closely correlated with changes in BHR to AMP (r = 0.511, p = 0.003) than with eNO (r = -0.373, p = 0.035). Additionally, changes in PC₂₀ AMP were correlated with changes in PC₂₀ methacholine (r = 0.451, p = 0.011) and eNO (r = -0.474, p = 0.006).

CONCLUSIONS

Changes in the BHR to AMP, and to a lesser extent eNO, correlate with asthma symptom control after ICS treatment. BHR to AMP may better reflect the relationship between improved airway inflammation due to ICS treatment and asthma symptoms.

Monitoring asthma in childhood: symptoms, exacerbations and quality of life

Monitoring asthma in children in clinical practice is primarily performed by reviewing disease activity (daytime and night-time symptoms, use of reliever medication, exacerbations requiring frequent use of reliever medication and urgent visits to the healthcare professional) and the impact of the disease on children's daily activities, including sports and play, in a clinical interview. In such an interview, most task force members also discuss adherence to maintenance therapy and the patients' (and parents') views and beliefs on the goals of treatment and the amount of treatment required to achieve those goals. Composite asthma control and quality of life measures, although potentially useful in research, have limited value in clinical practice because they have a short recall window and do not cover the entire spectrum of asthma control. Telemonitoring of children with asthma cannot replace face-to-face follow-up and monitoring because there is no evidence that it is associated with improved health outcomes.

Monitoring asthma in children

The goal of asthma treatment is to obtain clinical control and reduce future risks to the patient. To reach this goal in children with asthma, ongoing monitoring is essential. While all components of asthma, such as symptoms, lung function, bronchial hyperresponsiveness and inflammation, may exist in various combinations in different individuals, to date there is limited evidence on how to integrate these for optimal monitoring of children with asthma. The aims of this ERS Task Force were to describe the current practise and give an overview of the best available evidence on how to monitor children with asthma. 22 clinical and research experts reviewed the literature. A modified Delphi method and four Task Force meetings were used to reach a consensus. This statement summarises the literature on monitoring children with asthma. Available tools for monitoring children with asthma, such as clinical tools, lung function, bronchial responsiveness and inflammatory markers, are described as are the ways in which they may be used in children with asthma. Management-related issues, comorbidities and environmental factors are summarised. Despite considerable interest in monitoring asthma in children, for many aspects of monitoring asthma in children there is a substantial lack of evidence.

The clinician's guide on monitoring children with asthma

Based on a review of the evidence on the usefulness of monitoring disease outcome parameters in childhood asthma and the author's 20-yr clinical experience in managing childhood asthma, this article provides the clinician with up-to-date recommendations on how to monitor childhood asthma in everyday clinical practice. Monitoring should be focused on patient-centered outcomes, such as exacerbations and impact on sports and play. Composite asthma control measures, although reasonably validated, do not take exacerbations into account and have a short recall window, limiting their usefulness as a routine monitoring tool in clinical practice. Lung function, airways hyperresponsiveness, exhaled nitric oxide, and inflammatory markers in sputum are surrogate end points, of little if any interest to patients. There is no evidence to support their use as a monitoring tool in clinical practice; office spirometry may be used as additional information. Rather than monitoring surrogate end points, clinicians should focus on showing a genuine interest in the impact of asthma on children's daily lives, and building and maintaining a partnership by monitoring those characteristics of asthma which have the biggest impact on children (exacerbations and limitations in sports and play), and adjusting treatment accordingly.

Management of severe asthma in children

Children who are referred to specialist care with asthma that does not respond to treatment (problematic severe asthma) are a heterogeneous group, with substantial morbidity. The evidence base for management is sparse, and is mostly based on data from studies in children with mild and moderate asthma and on extrapolation of data from studies in adults with severe asthma. In many children with severe asthma, the diagnosis is wrong or adherence to treatment is poor. The first step is a detailed diagnostic assessment to exclude an alternative diagnosis ("not asthma at all"), followed by a multidisciplinary approach to exclude comorbidities ("asthma plus") and to assess whether the child has difficult asthma (improves when the basic management needs, such as adherence and inhaler technique, are corrected) or true, therapy-resistant asthma (still symptomatic even when the basic management needs are resolved). In particular, environmental causes of secondary steroid resistance should be identified. An individualised treatment plan should be devised depending on the clinical and pathophysiological characterisation. Licensed therapeutic approaches include high-dose inhaled steroids, the Symbicort maintenance and reliever (SMART) regimen (with budesonide and formoterol fumarate), and anti-IgE therapy. Unlicensed treatments include methotrexate, azathioprine, ciclosporin, and subcutaneous terbutaline infusions. Paediatric data are needed on cytokine-specific monoclonal antibody therapies and bronchial thermoplasty. However, despite the interest in innovative approaches, getting the basics right in children with apparently severe asthma will remain the foundation of management for the foreseeable future.