Prospective study of lung volumes in young asthmatic children.

In a 9-y prospective study, the occurrence and duration of lung volume abnormalities in 21 young asthmatic children (median age at recruitment 4 y, range 3-8 y) was determined. The median functional residual capacity (FRC) at recruitment was 135% of that predicted for height (range 79-187%) and 13 children were hyperinflated. The median FRC decreased significantly after 3 y of follow-up and by 9 y only one child remained hyperinflated. We conclude that persistent elevation of lung volume in young asthmatic children appears to be uncommon.