Table 1 Differences between groups in baseline characteristics

Sex, M:F

27:26

32:22

0.440

Age, years (mean ± SD)

56 ± 10

55 ± 10

0.624

BMI (mean ± SD)

22.2 ± 2.2

21.4 ± 2.3

0.069

Blood loss, ml (IQR)

300 (200, 450)

350 (250, 450)

0.231

Duration of operation, h (IQR)

3.5 (3, 4)

3.5 (3, 4)

0.211

Duration of ICU stay, h (IQR)

0 (0, 16)

0 (0, 17)

0.654

Duration of mechanical ventilation, h (IQR)

0 (0, 3)

0 (0, 5.3)

0.398

Duration of postoperative analgesia, h (IQR)

48 (41, 56)

48 (44, 55)

0.722

Types of operation performed

0.903

 Radical gastrectomy, n

14

15

 Radical colectomy, n

11

12

 Radical resection for rectal cancer, n

8

11

 Right hepatic resection, n

13

11

 Pancreatoduodenectomy, n

7

5

Tumor stage

0.442

 T0-1, n

1

1

 T2, n

15

8

 T3, n

23

28

 T4, n

14

16