Lung function and bronchial responsiveness in preschool children

It is hypothesized that childhood asthma, especially when not well controlled, may constitute a risk factor for the development of COLD in adulthood (Cropp, 1985), It is unknown whether lung injury during early life is a risk factor for the development of COLD in adulthood, Asthma often starts before schoolage (Cropp, 1985), Except for the disturbing symptoms, a reason for paying attention to asthma in preschool children is the hypothesis that adequate intervention may reduce the risk of COLD in adult life (Kerrebijn, 1982). To detect lung function abnormalities at as young as possible ages suitable methods should be available. Most lung function methods can only be performed in children over 6 years of age. Lung function was measured with the forced pseudo-random noise oscillation technique (FOT) (Uindser et al., 1976a) because only passive cooperation is needed. Resistance (R,) and reactance (X,) of the respiratory system are simultaneously measured over a frequency spectrum of 2 to 26 Hz. R, is mainly determined by the patency of the upper and large airways. X, is influenced by mass-inertial and elastic properties of the respiratory system. The applicability ofFOT in preschool children was investigated. The method is now suitable for use in clinical practice to measure lung function and BR in children from about 2lfz years of age. We measured airway patency, bronchial smooth muscle tone and BR in preschool asthmatic children. Secondly, we investigated whether lung injury during early influences the development of lung function and bronchial responsiveness in children who do not have a genetic predisposition of asthma. This was investigated in children who had infant bronchiolitis, in subjects who survived infant bronchopulmonary dysplasia after neonatal respiratory distress syndrome and in individuals who experienced a near-drowning accident. The results are compared to data found in healthy controls

The effect of stepping down combination therapy on airway hyperresponsiveness to mannitol

SummaryRationaleControversy exists about the safety of long acting beta2-agonist (LABA) treatment, in particular in children. Combination therapy with a LABA and an inhaled corticosteroid (ICS) is prescribed to children with moderate asthma and can be stepped down by withdrawal of the LABA when asthma is well controlled.ObjectiveTo analyze the effect of stepping down from LABA/ICS combination therapy to monotherapy with the same dose of ICS on the airway response to mannitol in asthmatic children.Methods17 children, aged 12–17 years, with clinically stable asthma, receiving combination therapy, were analyzed in this observational prospective open-label study. Children performed a mannitol challenge at baseline and 30±4 days after their medication was stepped down to ICS monotherapy. The changes in the provoking dose of mannitol to cause a 15% fall in FEV1 (PD15), response-dose ratio and recovery time following a short acting beta2-agonist to ≥95% of baseline FEV1 were assessed.ResultsMannitol PD15 and response-dose ratio did not significantly change after stepping down. The recovery time following a short acting beta2-agonist to ≥95% of baseline FEV1 was significantly shorter (p=0.01) after the withdrawal of the LABA.ConclusionsIn short-term follow-up, stepping down clinically stable asthmatic children from combination therapy to monotherapy with an ICS does not change airway hyperresponsiveness (AHR) to mannitol but does shorten recovery time to baseline lung function following a rescue short acting beta2-agonist

General practitioners' prescribing behaviour as a determinant of poor persistence with inhaled corticosteroids in children with respiratory symptoms:Mixed methods study

OBJECTIVES: To evaluate general practitioners’ (GPs’) prescribing behaviour as a determinant of persistence with and adherence to inhaled corticosteroids (ICS) in children. DESIGN: Prospective observational study of persistence with and adherence to ICS followed by a focus group study of the GPs prescribing this treatment. SETTING: 7 primary care practices in the area of Zwolle, the Netherlands. PARTICIPANTS: 134 children aged 2–12 years had been prescribed ICS in the year before the study started by their 19 GPs. MAIN OUTCOME MEASURES: Patterns and motives of GPs’ prescribing behaviour and the relationship with persistence with and adherence to ICS. RESULTS: GPs’ prescribing behaviour was characterised by prescribing short courses of ICS to children with various respiratory symptoms without follow-up for making a diagnosis of asthma. This was driven by the GPs’ pragmatic approach to deal with the large number of children with respiratory symptoms, and by beliefs about ICS which differed from currently available evidence. This prescribing behaviour was the main reason why 68 (51%) children did not persist with the use of ICS. In children with persistent use of ICS and a GP's advice to use ICS on a daily basis, the median (IQR) adherence was 70% (41–84%), and was similar for patients with persistent asthma and children lacking a diagnosis or symptoms of asthma. CONCLUSIONS: Inappropriate prescription of ICS to children by GPs is common and drives the lack of persistence with ICS therapy in primary care. This finding should be taken into account when interpreting data from large prescription database studies. Improving primary healthcare providers’ knowledge and competence in diagnosing and managing asthma in children is needed