RT Journal Article SR Electronic T1 Tidal expiratory flow limitation and chronic dyspnoea in patients with cystic fibrosis JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 492 OP 498 DO 10.1183/09031936.02.00220702 VO 19 IS 3 A1 D. Goetghebeur A1 D. Sarni A1 Y. Grossi A1 C. Leroyer A1 H. Ghezzo A1 J. Milic-Emili A1 M. Bellet YR 2002 UL http://erj.ersjournals.com/content/19/3/492.abstract AB Cystic fibrosis (CF) eventually leads to hyperinflation linked to tidal expiratory flow limitation (FL) and ventilatory failure. Presence of FL was assessed at rest in 22 seated children and adults with CF (forced expiratory volume in one second (FEV1) range: 16–92% predicted), using both the negative expiratory pressure (NEP) technique and the “conventional” method based on comparison of tidal and maximal expiratory flow/volume curves. In addition, chronic dyspnoea was scored with the modified Medical Research Council (MRC) scale. Measurements were made before and 15 min after inhalation of salbutamol. With NEP, FL was present in only three malnourished patients, who had the lowest FEV1 values (16–27% pred) and claimed very severe dyspnoea (MRC score 5). By contrast, an additional seven patients were classified as FL with the conventional method. Six of these patients had little or no dyspnoea (MRC scores 0–1). Salbutamol administration had no effect on the extent of FL, and the concomitant decrease in functional residual capacity (FRC) was too small to play any clinically significant role. This study concluded that in seated patients with cystic fibrosis, expiratory flow limitation is absent at rest, unless the forced expiratory volume in one second is <30% predicted. If present, expiratory flow limitation is associated with severe chronic dyspnoea. The conventional method for assessing expiratory flow limitation is not reliable and bronchodilator administration has little effect on expiratory flow limitation.