American Thoracic Society Documents

1 American Thoracic Society DocumentsAn Official American Thoracic Society /EuropeanRespiratory Society Statement: pulmonary FunctionTesting in Preschool ChildrenNicole Beydon, Stephanie D. Davis, Enrico Lombardi, Julian L. Allen, Hubertus G. M. Arets, Paul Aurora,Hans Bisgaard, G. Michael Davis, Francine M. Ducharme, Howard Eigen, Monika Gappa, Claude Gaultier,Per M. Gustafsson, Graham L. Hall, Zolta n Hantos, Michael J. R. Healy, Marcus H. Jones, Bent Klug,Karin C. L drup Carlsen, Sheila A. McKenzie, Franc ois Marchal, Oscar H. Mayer, Peter J. F. M. Merkus,Mohy G. Morris, Ellie Oostveen, J. Jane Pillow, Paul C. Seddon, Michael Silverman, Peter D. Sly, Janet Stocks,Robert S. Tepper, Daphna Vilozni, and Nicola M. Wilson, on behalf of the American Thoracic Society /European Respiratory Society Working Group on Infant and Young Children pulmonary Function TestingThis official statement of the American Thoracic Society (ATS) and the European Respiratory Society (ERS) wasapproved by the ATS Board of Directors, September2006, and the ERS Executive Committee, December2006 CONTENTSS ection 1.

2 The Next (Chair),NicoleBeydon, ,ClaudeGaultier, Enrico Lombardi, Mohy G. Morris, Janet StocksSection 2. Clinical (Chair),PaulAurora,Francine ,Michael J. R. Healy, Bent Klug, Paul C. Seddon, Janet StocksSummaryIntroductionFeasibilityWhat Is Normal?Variability of a TestDiagnosing Respiratory DisordersMonitoring Disease Progress and Response to InterventionsConclusions and Future DirectionsSection 3. SpirometryPaul Aurora (Co-chair), Howard Eigen (Co-chair), , , ,JanetStocks,Robert S. Tepper, Daphna VilozniSummaryIntroductionPhysiological BackgroundProceduresInterpretation of ResultsConclusions and Future DirectionsSection 4. Tidal Breathing MeasurementsPaul C. Seddon (Chair), Julian L. Allen, Karin C. L drupCarlsen, Oscar H. MayerSummaryIntroductionTidal Expiratory Flow AnalysisThoracoabdominal Motion AnalysisConclusions and Future DirectionsSection 5.

3 The Interrupter TechniqueEnrico Lombardi (Chair), Hubertus G. M. Arets,Nicole Beydon, Hans Bisgaard, Claude Gaultier, Bent Klug,This document has an online supplement, which is accessible from this issue stable of contents at J Respir Crit Care Med Vol 175. pp 1304 1345, 2007 DOI: address: A. McKenzie, Peter J. F. M. Merkus, Paul C. Seddon,Peter D. SlySummaryIntroductionBackgroundProcedur esInterpretation of ResultsConclusions and Future DirectionsSection 6. The Forced Oscillation TechniqueFranc ois Marchal (Chair), G. Michael Davis, Francine , Graham L. Hall, Zolta n Hantos, Ellie OostveenSummaryIntroductionBackgroundPro ceduresInterpretation of ResultsClinical ApplicationsConclusions and Future DirectionsSection 7. The Multiple-Breath Inert Gas Washout TechniquePer M. Gustafsson (Chair), Janet Stocks, Paul Aurora, J.

4 JanePillow, Monika GappaSummaryBackgroundProceduresInterpre tation of ResultsConclusions and Future DirectionsSection 8. Bronchial Responsiveness TestsNicole Beydon (Chair), Hans Bisgaard, Claude Gaultier,Enrico Lombardi, Michael Silverman, Peter D. Sly,Janet Stocks, Nicola M. WilsonSummaryIntroductionBronchodilator ResponsivenessPharmacological Challenge TestingCold Air ChallengeClinical ApplicationsConclusions and Future DirectionsSection 1. The Next FrontierIn older children, measuring lung function is integral for under-standing respiratory physiology and for clinical function tests for infants and children younger thanAmerican Thoracic Society Documents13052 years are used as both research and clinical tools. The use-fulness of these tests has benefited from approximately 15 yearsof work by joint American Thoracic Society (ATS)/EuropeanRespiratory Society (ERS) working parties and task forces (1,2).

5 However, children aged 2 to 6 years old represent one ofthe major challenges in lung function assessment. Evaluatinglung function in this age group is important, not only for clinicalreasons but also due to the considerable growth and develop-ment of the respiratory system that occurs, with associatedchanges in lung mechanics (3). Children commonly present withrecurrent cough and wheeze during this period. Many of thesechildren will lose their symptoms as they grow, yet others willcontinue to have asthma that persists into adult life (4). Thetreatment implications of these two clinical patterns are differ-ent, yet we are currently hampered by a lack of objective assess-ments to help distinguish between these two patterns. In addi-tion, children recovering from chronic neonatal lung diseaseand children with cystic fibrosis (CF) are prone to recurrentor persistent respiratory symptoms.

6 Objective assessments ofpulmonary function in these children would be expected to im-prove clinical management. The importance of continuous, lon-gitudinal assessments of lung function from birth throughoutchildhoodcannotbeunderestimate dinunderstandingtheevolu-tion and natural history of disease present a number of special challenges. Thechildren are generally too old to sedate for pulmonary functiontesting (PFT), as is done with infants, and measurement of lungfunction under anesthesia is neither ethically acceptable norphysiologically relevant to clinical management. Children in thisagegrouparenotabletovoluntarilyperfo rmmanyofthephysio-logicalmaneuversrequir edforthepulmonaryfunctiontestsusedin older children and adults. They have a short attention spanand are easily distracted. Due to these issues, the children needto be engaged and encouraged by the operator to participate inthe number of pulmonary function tests have been attemptedin conscious children within the preschool age group.

7 Theseinclude the following: standard spirometry (5 11), maximal flowreferenced to functional residual capacity (V maxFRC) (12 14),forced oscillation (FOT) (15 20), interrupter resistance (Rint)(19 27),specificairwayresistance(sRaw)measur edinaplethys-mograph (19, 20, 28), functional residual capacity (FRC) usinggas dilution techniques (13, 26, 29), and measurements of gas-mixing indices (30, 31). Unlike the situation that existed whenpulmonary function tests for infants were first developed, com-mercial equipment is available for most of these tests, althoughnot specifically designed for preschool-aged children. The impli-cations of using equipment in this age group that is designedfor older and larger individuals must be understood. Equipmentdead space, resistance, and software programs designed foradults,notyoungchildren,mustbeevaluat edtounderstandhowthese issues impact pulmonary function measurements in thepreschool has been stressed by the ATS/ERS Working Party onInfantPulmonaryFunctionTesting,nomatte rwhichtestisbeingused the operator must be given access to raw data from theequipment.

8 As the field develops and the knowledge of respira-tory physiology in this age group expands, having access to rawdata will allow investigation of different and more appropriatealgorithms and may result in improved disease joint ATS/ERS task force has produced recommenda-tions for the tests currently used in the preschool age section of this document was written by a subcommitteeof the present task force, and includes the current knowledgeand recommendations to guide technical and clinical recommendations were based on reliable scientific evi-dence, documented by references, and validated by the subcom-mittee experts. However, in many situations, insufficient dataexist to make definitive recommendations. This document high-lights the current state of knowledge and where further data areneeded. Recommendations will need to be revised periodicallyuntil sufficient evidence has been collected to make definitiveguidelines in certain situations.

9 This document will address thefollowing topics: (1) clinical implications of PFT in preschoolchildren, (2) spirometry, (3) tidal breathing measurements, (4)the interrupter technique, (5) the FOT, (6) gas washout tech-niques, and (7) bronchial responsiveness for equipment used in an infant/preschoolerpulmonary function laboratory have been previously reported(32), and a review of these systems and their hygiene aspects isbeyond the scope of these recommendations. However, it isimportanttohighlightthatthetotalappara tusdeadspaceshouldbe minimized where possible, although this requirement doesnot preclude the use of bacterial filters, and should in generalbe lower than to 2 ml/kg body weight (32).The main aim of these recommendations is to provide aresource for the user of these preschool techniques, to facilitategood laboratory practice, interpretation of measurements, andcomparison among centers.

10 These recommendations are ex-pected to help the development of future methodological re-search in either single- or multicenter clinical studies, which areneededtosupport to the technical aspects of this document for developingproper equipment and ideal pulmonary function test in preschool children isone that is applicable to any age so that longitudinal studies canbe conducted monitoring individual children from infancy toadulthood, simple to perform, safe, reproducible, sensitiveenough to detect changes with growth and distinguish clearlybetween health and disease, and acceptable to both the subjectand parents. As with pulmonary function tests in infants, specialattention must be paid to the measurement conditions underwhich the tests are performed, and the impact of these measure-ment conditions on the accuracy of test results must be consid-ered.