on behalf of the American Thoracic Society/ European Respiratory Society Working Group on Infant and Young Children Pulmonary Function Testing This official statement of the American Thoracic Society (ATS) and the European Respiratory Society (ERS) was approved by the ATS Board of Directors, September 2006, and the ERS Executive Committee, December 2006 6. Further multidisciplinary work is required to investigate the best combination of tests (e.g., structure, function, inflammation, atopy) and challenges (e.g., pharmaceutical vs. physical) to investigate specific clinical entities during early childhood.

Oscillometry (also known as the forced oscillation technique) measures the mechanical properties of the respiratory system (upper and intrathoracic airways, lung tissue and chest wall) during quiet tidal breathing, by the application of an oscillating pressure signal (input or forcing signal), most commonly at the mouth. With increased clinical and research use, it is critical that all technical details of the hardware design, signal processing and analyses, and testing protocols are transparent and clearly reported to allow standardisation, comparison and replication of clinical and research studies. Because of this need, an update of the 2003 European Respiratory Society (ERS) technical standards document was produced by an ERS task force of experts who are active in clinical oscillometry research.The aim of the task force was to provide technical recommendations regarding oscillometry measurement including hardware, software, testing protocols and quality control.The main changes in this update, compared with the 2003 ERS task force document are 1) new quality control procedures which reflect use of “within-breath” analysis, and methods of handling artefacts; 2) recommendation to disclose signal processing, quality control, artefact handling and breathing protocols (e.g. number and duration of acquisitions) in reports and publications to allow comparability and replication between devices and laboratories; 3) a summary review of new data to support threshold values for bronchodilator and bronchial challenge tests; and 4) updated list of predicted impedance values in adults and children.

Abstractwheeze/asthma" associated with persistent wheezing at any age and with Background -There is increasing evidence methacholine hyperresponsiveness, peak that wheezing during childhood may be a flow variability, and markers of atopy. heterogeneous condition, and that differ- (Thorax 1997;52:946-952) ent forms of wheezing may be associated with different risk factors and prognosis. Keywords: methacholine, peak flow, atopy, wheezing, The aim of this study was to determine if children. measures of airway lability and of atopy could identify distinct wheezing phenoThere is increasing evidence to suggest that types during childhood.wheezing in childhood may represent a heteroMethods -In a cohort of children followed geneous condition, with distinct phenotypic from birth peak flow variability (n=600) expressions associated with different clinical was evaluated and methacholine challenge manifestations and risk factors. 1 We recently responsiveness (n=397) was measured at reported, for example, that at least two different age 11 in relation to wheezing before the wheezing syndromes coexist in infants and age of three, and at age six and 11 years young children 2 : wheezing which is associated total serum IgE and skin test reactivity to with lower levels of lung function at birth and allergens were determined.with a high probability of remission before six Results -Neither positive peak flow years of age and wheezing associated with the variability nor methacholine hyperclassical risk factors for asthma and persistence responsiveness measured at age 11 were of symptoms at the age of six. Although a associated with wheezing occurring only strong correlation between bronchial hyperduring the first three years of life. Both responsiveness and frequency and severity of methacholine hyperresponsiveness and wheezing is known to exist among children positive peak flow variability were asaged 8-15 years, 3-7 no such correlation was sociated with wheezing at both ages six recently found among children aged 4-5 years 8 and 11 (OR 5.1 (95% CI 2.4 to 10.6) and which suggests that wheezing during the tod-2.3 (1.2 to 4.5), respectively). In addition, dler years may be different phenotypically from positive peak flow variability was aswheezing in older children. sociated with wheezing up to the age of six Both methacholine responsiveness and peak but not at age 11 in non-atopic children flow variability have been used to assess airway (OR 2.9 (95% CI 1.0 to 8.8)). Methacholine lability in children of different ages. Although hyperresponsiveness measured at age 11 the association between methacholine hyperwas more frequently observed in boys (OR responsiveness and markers of atopy has been 2.1 (95% CI 1.2 to 3.5)) and was strongly well established [9][10][11] there is little information associated with serum IgE levels measured on the alterations in the airway responsible for at ages six and 11 (p<0.001) and with posiincreased peak flow variability as assessed by tive skin test reactivity (OR 4.5 (95% CI the use of peak flow me...

Although pulmonary function testing plays a key role in the diagnosis and management of chronic pulmonary conditions in children under 6 years of age, objective physiologic assessment is limited in the clinical care of infants and children less than 6 years old, due to the challenges of measuring lung function in this age range. Ongoing research in lung function testing in infants, toddlers, and preschoolers has resulted in techniques that show promise as safe, feasible, and potentially clinically useful tests. Official American Thoracic Society workshops were convened in 2009 and 2010 to review six lung function tests based on a comprehensive review of the literature (infant raised-volume rapid thoracic compression and plethysmography, preschool spirometry, specific airway resistance, forced oscillation, the interrupter technique, and multiple-breath washout). In these proceedings, the current state of the art for each of these tests is reviewed as it applies to the clinical management of infants and children under 6 years of age with cystic fibrosis, bronchopulmonary dysplasia, and recurrent wheeze, using a standardized format that allows easy comparison between the measures. Although insufficient evidence exists to recommend incorporation of these tests into the routine diagnostic evaluation and clinical monitoring of infants and young children with cystic fibrosis, bronchopulmonary dysplasia, or recurrent wheeze, they may be valuable tools with which to address specific concerns, such as ongoing symptoms or monitoring response to treatment, and as outcome measures in clinical research studies.