ATS Pulmonary Function Laboratory Manual

ATS Pulmonary Function Laboratory Management & Procedure Manual | 3rd Edition

the plethysmograph to improve cooperation. The technique is feasible in approximately 80% of 3- to 6-year-olds and nearly 100% of 5- to 6-year-olds (25). A specially adapted facemask may be used to prevent nasal breathing. However, equal success has been demonstrated in 3- to 6-year-olds when using a nose clip and mouthpiece (25). In contrast to infant lung function and preschool spirometry, there exists no consensus with respect to sRaw measurement conditions, quality control, methods of analyzing and reporting results, or outcome measures for young children (26). Current default values for reference equations in commercially available equipment are based on data collected under BTPS conditions, rather than the electronic thermal compensation that is now applied. These equations generally under-estimate values observed in healthy children, and thus over-estimate morbidity in those with lung disease. In addition, the existing reference equations were developed from measurements with methodological dif- ferences, so that reported mean (SD) predicted values in young children range from 0.55 (0.18) to 1.29 (0.30) kPa∙s (27). Although sRaw is relatively constant during the preschool years, it appears to decrease slightly with age and is also lower in girls than boys, such that predicted values and the upper limit of normal should ideally be derived from reference equations rather than a fixed threshold (27). In contrast to spirometric parameters, ethnic group does not appear to influence measures of sRaw, as this variable is internally adjusted for lung volume. References 1. DuBois AB, Bothelho SY, Comroe JH Jr. A new method for measuring airway resistance in man using a body plethysmograph: values in normal subjects and in patients with respiratory disease. J Clin Invest 1956;35:327–335. 2. Niewoehner DE, Kleinerman J. Morphologic basis of pulmonary resistance in the human lung and the effects of aging. J Appl Physiol 1974;36:412–418. 3. Van Brabandt H, Cauberghs M, Verbeken E, et al . Partitioning of pulmonary impedance in excised human and canine lungs. J Appl Physiol 1983;55:1733–1742. 4. American Association for Respiratory Care. Clinical Practice Guideline: body plethysmography. Respir Care 2001;46:506–513. 5. Watanabe S, Renzetti SD Jr, Begin R, Bigler AH. Airway responsiveness to a bronchodilator aerosol. I. Normal human subjects. Am Rev Respir Dis 1974;109:530–537. 6. Fish JE, Rosenthal RR, Batra G, Menkes H, Summer W, Permutt S, Norman P. Airway responses to methacholine in allergic and nonallergic subjects. Am Rev Respir Dis 1976;113:579–586. 7. American Thoracic Society Subcommittee on Inhalation Challenges. Guidelines for bronchial inha- lation challenges with pharmacologic and antigenic agents. ATS News , Spring 1980:11–19. 8. American Thoracic Society/European Respiratory Society Task Force. Standardization of spirometry. Eur Respir J 2005;26:319–338. 9. American Thoracic Society Committee on Proficiency Standards for Clinical Pulmonary Laborato- ries. Quality assurance in pulmonary function laboratories. Am Rev Respir Dis 1986;134:625–627. 10. Brown R, Hoppin FG, Ingram RH Jr, Saunders NA, McFadden ER Jr. Influence of abdominal gas on the Boyle's law determination of thoracic gas volume. J Appl Physiol 1978;44:469–473. 11. American Association for Respiratory Care. Clinical Practice Guideline: spirometry. 1996 update. Respir Care 1996;41:629–636. 12. Kanner RE, Morris AH, Crapo RO, Gardner RM, editors. Clinical pulmonary punction testing: a manual of uniform laboratory procedures for the intermountain area, 2nd ed. Salt Lake City, UT: Intermountain Thoracic Society; 1984.

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