Obstructive group

(%FEV₁ ≤ 70%, n = 22)

Non-obstructive group

(%FEV₁ > 70%, n = 33)

Preoperative baselines

COPD

(C-group, n = 22)

Tiotropium

Smoker

(S-group, n = 10) Tiotropium

Non-smoker

(N-group, n = 23) Control

p value

Mean ± SD

Mean ± SD

Mean ± SD

C-g vs S-g

C-g vs N-g

S-g vs N-g

base-VC (L)

3.13 ± 0.59

3.01 ± 0.50

3.01 ± 0.71

0.2164

0.1525

0.3453

base-FEV1 (L)

1.86 ± 0.46

2.22 ± 0.46

2.31 ± 0.61

0.0133

0.0254

0.3399

base-VC% (predicted, %)

109.9 ± 14.0

102.6 ± 16.0

113.9 ± 17.4

0.0576

0.2062

0.0450

base-FEV1/FVC (%)

60.4 ± 7.4

80.4 ± 1.9

76.6 ± 4.5

<0.0001

<0.0001

0.3565