Table 2

Ventilatory pattern at maximal exercise in patients with pulmonary fibrosis, cystic fibrosis, chronic obstructive pulmonary disease (COPD), healthy control subjects and transplanted patients

Pulmonary fibrosis (PF)Cystic fibrosis (CF)COPDHealthy controls (HC)Transplanted (T)
VT (litres)0.75±0.10*** vs HC, T; * vs COPD0.79±0.07*** vs HC, T; * vs COPD1.25±0.08*** vs HC2.60±0.332.30±0.22
ΔVRC (%VT)41.3±7.840.0±4.750.0±3.247.6±3.941.1±3.3
ΔVAB (%VT)58.7±7.860.0±4.750.0±3.252.4±3.958.9±3.3
TTOT (s)1.45±0.24*** vs COPD1.86±0.13*** vs COPD3.16±0.23*** vs T; ** vs HC2.24±0.242.16±0.08
TI (s)0.62±0.10*** vs COPD; ** vs HC; * vs T0.81±0.07* vs HC1.03±0.061.09±0.110.93±0.04
TE (s)0.83±0.15*** vs COPD1.05±0.06*** vs COPD2.12±0.18*** vs T; ** vs HC1.15±0.131.23±0.06
Duty cycle (TI/TTOT, %)43.8±1.9* vs HC43.5±0.9* vs HC33.9±1.1*** vs PF, CF, HC, T49.0±1.0** vs T43.6±1.03
Breath. frequency (/min)49.4±6.1*** vs CF, COPD, HC, T33.9±2.3*** vs COPD21.3±1.6** vs HC, T30.0±3.228.7±1.02
Minute ventilation (l/min)34.8±5.4*** vs HC, T26.8±2.7*** vs HC, T24.9±1.4*** vs HC,T73.1±8.962.3±5.8
Mean inspiratory flow (VT/TI, l/s)1.34±0.17*** vs HC, T1.04±0.12*** vs HC, T1.25±0.06*** vs HC, T2.50±0.292.50±0.20
Borg breath4.2±1.2(n=8)5.7±1.3(n=7)5.8±0.6(n=13)4.0±0.4(n=10)7.13±0.9(n=8)
Borg leg2.5±1.2(n=8)5.1±1.3(n=7)5.7±0.8(n=13)5.7±0.6(n=10)7.75±0.7(n=8)
  • *p<0.05, **p<0.01, ***p<0.001.

  • TE, expiratory time; TI, inspiratory time; TTOT, total respiratory cycle time;.VT, tidal volume; ΔVAB, percentage contribution of abdomen to tidal volume; ΔVRC, percentage contribution of rib cage to tidal volume.