Table 1 Baseline and intraoperative characteristics

Age; yrs

52 ± 13

53 ± 17

0.06

Height; cm

172 ± 8

171 ± 9

0.01

1

Weight; kg

75 ± 11

77 ± 21

0.15

BMI; kg/m²

25 ± 4

26 ± 5

16/13

0.11

Sex (m/f); n

18/13

0.06

ASA score (1/2/3); n

11/17/3

7/16/6

0.34

Smoking history (yes/no); n

8/23

6/23

0.12

Type of surgery (upper abdominal/colorectal); n

21/10

21/8

0.10

 Liver resection; n

9

18

 Pancreaticoduodenectomy; n

8

1

 Rectal surgery; n

6

6

 Colectomy; n

3

1

 Left pancreatectomy; n

2

2

 Sigma resection; n

1

1

 Total pancreatectomy; n

1

0

 Sarcoma resection; n

1

0

Duration of surgery; min

267 ± 106

228 ± 92

0.39

Intraoperative variables

 TWA MAP; mmHg

71 ± 8

78 ± 9

0.51a

 TWA HR; bpm

70 ± 12

72 ± 12

0.78a

 TWA CVP; mmHg

8 ± 2

10 ± 3

0.14a

 TWA FTc; msec

353 ± 22

359 ± 21

0.45a

 TWA SV; ml

78 ± 17

80 ± 16

0.99a

TWA end-tidal sevoflurane; %

2 (1.8–2.1)

1.8 (1.7–2)

0.02b

Fentanyl, μg

1006 ± 423

847 ± 353

0.63a

Total fluid intake; ml^c

4567 (3500–5800)

3044 (2125–3825)

0.01b

Crystalloids; ml

4100 (3025–5041)

1300 (955–2000)

< 0.001b

Colloids; ml

N.a.

1250 (750–1500)

N.a.

Number of boluses; n

9 (6–12)

5 (3–6)

< 0.001b

Vasopressor therapy (yes/no); n

23/8

13/16

0.03d

Phenylephrine; mg

0.32 (0.14–0.8)

0.29 (0.18–0.56)

1.00b

Norepinephrine; mg

0.1 (0.06–0.12)

0.02

1.00b

Urinary output; ml

300 (200–450)

300 (135–475)

0.83b

Blood loss; ml

400 (175–600)

300 (150–1000)

0.59b

TWA BE; mmol/l

−1.9 ± 1.9

−2.1 ± 2

0.63a

TWA FiO₂, %

79 (78–80)

79 (77–80)

0.94b

PaO₂ (start of surgery); mmHg

366 (324–453)

400 (305–458)

0.30b

 PaO₂/FiO₂ ratio; mmHg

454 (385–480)

453 (383–516)

0.70b

PaO₂ (end of surgery); mmHg

381 (326–429)

392 (359–428)

0.80b

 PaO₂/FiO₂ ratio; mmHg

462 (404–500)

488 (443–526)

0.37b

PaCO₂; mmHg

40 ± 3

41 ± 3

0.55a