11 - Pulmonary Function Tests in Infants and Preschool Children

Abstract

Objective measures of lung function are critical for the care and management of pediatric lung disease. Challenges are associated with obtaining lung function testing in infants and preschoolers. Sedation, specialized equipment, and significant training are often required when performing infant lung function tests. There is also a lack of robust reference data in infants. Given this, many laboratories are unable to routinely conduct infant pulmonary function tests, and most testing occurs in specialized research laboratories. Preschoolers are often unable to fully cooperate for testing that requires specialized respiratory maneuvers, such as taking large breaths or forced expiration; thereby, tidal breathing techniques may be preferred. Preschool spirometry guidelines have been adapted to accommodate for the emotional development and the unique respiratory physiology of this age group. Pulmonary function tests have been reported to be abnormal in both infants and preschoolers who suffer from a variety of respiratory symptoms and/or diseases, including cystic fibrosis, bronchopulmonary dysplasia, and recurrent wheeze or asthma. There is an urgent need to evaluate and develop lung function techniques that are accurate, noninvasive, less technically demanding, transferrable across sites, and simpler to obtain. Identifying abnormalities through lung function testing in the youngest age group allows for early intervention and the potential to change the trajectory of disease. In this chapter, we will review the challenges associated with assessing lung function in the youngest population, infant and preschool pulmonary function testing methodology, the principles behind these measurements, and the sensitivity of these tests in detecting disease.