The American review of respiratory disease
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Am. Rev. Respir. Dis. · Sep 1988
Comparative StudyShape of forced expiratory flow-volume curves in infants.
An inflatable cuff was used to generate partial forced expiratory flow-volume (FEFV) curves in 36 infants with and without obstructive airway disease. Curves were recorded in each infant over a range of compression pressures as high as and exceeding the pressure required for the maximal partial FEFV curve. The maximal curves were quantitated and compared with passive compliance and conductance of the respiratory system and absolute lung volume measured by whole-body plethysmography. ⋯ Two parameters, the ratio of forced maximal expiratory flow (measured from the maximal partial FEFV curve) to tidal expiratory flow (measured from the expiratory flow-volume curve of tidal breathing) at midtidal volume (Vm1d(forced/tidal] and the minimal compression pressure required to generate maximal expiratory flow at FRC (Pmin), satisfactorily quantified respiratory function without the need for size correction with absolute lung volume. In addition, Vm1d(forced/tidal) provides an index of expiratory flow reserve. We conclude that useful information can be provided from the shape of a partial FEFV curve in an infant, provided that curves are generated by a standardized compression pressure.(ABSTRACT TRUNCATED AT 250 WORDS)