Respiratory studies in children. IX. Relationships between mechanical properties of the lungs, lung volumes and ventilatory capacity in healthy children 7-15 years of age.

The pulmonary function in children has attracted a great deal of interest in recent years as it has been found that methods which are used for studies in adults are also applicable in children. Although several studies on lung volumes and ventilatory capacity have been reported in healthy and asthmatic children [l, 2, 11, 12, 171, the mechanics of breathing has not been as widely investigated. There exists abundant literature concerning the mechanics of breathing in adults, as well as a few studies in newborns. Of the studies in which children were included [3, 17, 20, 251 the study of Helliesen et al. [17], is the largest, giving data of the mechanics of breathing and the lung volumes in 77 healthy children 5-17 years of age. The relationship between the mechanics of breathing and body size found both in healthy children [17] and adults [13] is not close enough to permit assessment of more than gross abnormalities. The fact that a closer correlation has been found between lung compliance and vital capacity and functional residual capacity [17, 201, has prompted us to determine if the