Table 1

 Lung mechanics in 27 subjects before and 6 months after LVRS

ParameterBaselineAfter LVRSp value
PEF, peak expiratory flow; TPpeak, peak transpulmonary pressure during a forced expiratory manoeuvre; TLC, total lung capacity; RV, residual volume; RV/TLC, RV/TLC ratio; Rle, expiratory lung resistance; Rli, inspiratory lung resistance; coefficient Pel, elastic recoil pressure at TLC/TLC; FVC, forced expiratory vital capacity; FEV1, forced expired volume in the first second of forced expired manoeuvre; NFEV1, FEV1 obtained using no compression method; DFEV1, (NFEV1 − FEV1)/FEV1.
PEF (l/s)2.9 (0.83)3.3 (1.7)>0.2
TPpeak (cm H2O)128 (73)130 (56)>0.42
TLC (l)9.7 (1.3)8.8 (1.1)<0.003
RV (l)6.5 (1.2)5.3 (1.3)<0.001
RV/TLC (%)67 (7)59 (9)<0.001
Rle (cm H2O/l/s)26 (17.9)19 (13.7)<0.01
Rli (cm H2O/l/s)5 (2.2)4 (2.4)>0.11
Coefficient Pel (cm H2O/l)1.15 (0.49)1.59 (0.81)<0.005
FVC (l)2.35 (0.75)2.87 (0.79)<0.005
FEV1 (l)0.87 (0.24)1.07 (0.38)<0.005
FEV1 (% predicted)26 (8)31 (11)0.005
NFEV1 (l)1.44 (0.37)1.53 (0.48)>0.15
DFEV1 (% change from baseline)74 (52)48 (27)<0.05