Respiratory system compliance (Crs) in infants with cystic fibrosis (CF) has been reported as decreased or not different compared with healthy control subjects; however, the reported measurements of Crs were "quasi- static" or by the single-breath occlusion technique, with all measurements limited to tidal lung volume, as well as using inspiratory rather than expiratory pressures. We compared the passive elastic properties of the respiratory system of sleeping infants with CF (n = 10) and healthy control subjects (n = 34) by measuring static deflation pressure-volume (PV) curves from a lung volume at 30 cm H2O (V30) to FRC. There was no significant difference between the groups for Crs, which was measured as the slope between airway relaxation pressures of 5 and 15 cm H2O, the linear portion of the deflation PV curve. In addition, when PV curves were normalized to V30, there were no differences between the infants with CF and healthy control subjects in the fractional volumes at any airway pressure. The infants with CF had significantly lower forced expiratory flows; however, lower flows did not correlate with fractional volumes measured from the PV curve. Our findings indicate that infants with CF have normal elastic properties of the respiratory system.
|Original language||English (US)|
|Number of pages||3|
|Journal||American journal of respiratory and critical care medicine|
|State||Published - Sep 1 2004|
- Pressure-volume curves
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine