FORCED EXPIRATORY MANEUVERS IN CHILDREN AGED 3 TO 5 YEARS

There is no consensus about reproducibility and reliability of spirometry in young children. We evaluated forced expiratory maneuvers from 98 children aged 3 to 5 years with a variety of respiratory disorders before and after bronchodilator treatment. Forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV(1)) were analyzed for reproducibility by the American Thoracic Society criteria and for reliability based on the coefficient of variation (CV%). Over 90% of the patients cooperated, however, while 95% could exhale for at least 1 second, very few generated an FEV(1) on all 6 ''best'' efforts. This clearly improved with age. Of all patients nearly 60% performed reproducible pre- and postbronchodilator sets of FVC but only 32% performed reproducible sets of FEV(1). Based on the CV%, those patients who could reproducibly perform an FVC and FEV(1) did it quite reliably (mean CV%, 9.38 and 7.01 for FVC and FEV(1), respectively). We conclude that while some very young children can perform spirometry, reliability of performance cannot be assumed in this age group. (C) 1994 Wiley-Liss, Inc.