Table 1 Demographic characteristics of the study population

Male, n (%)

52

(57.8)

85

(62.5)

0.48

Age, years median [IQR]

66

[52–78]

67

[57–76]

0.86

BMI median [IQR]

24

[22–30]

25

[22–28]

0.84

 coronary disease

25

(27.8)

29

(21.3)

0.26

 arterial occlusive disease

16

(17.8)

17

(12.5)

0.36

 cardiac insufficiency

5

(5.6)

6

(4.4)

0.26

 chronic renal failure

5

(5.6)

11

(8.1)

0.64

 chronic dialysis

1

(1.1)

1

(0.7)

1

 cirrhosis

4

(4.4)

6

(4.4)

1

 diabetes mellitus

16

(17.8)

19

(13.9)

0.44

 immunodeficiency

16

(17.8)

23

(16.9)

0.86

 abdominal surgery

39

(43.3)

64

(47.1)

0.58

Prior antibiotic treatment, n (%)

14

(15.6)

70

(51.5)

< 0.001

Generalised peritonitis, n (%)

28

(31.1)

56

(41.2)

0.62

Localisation, n (%)

0.36

 colon

38

(42.2)

61

(44.9)

 small intestine

28

(31.1)

28

(20.6)

 stomach/duodenum

15

(16.7)

20

(14.7)

 other

9

(10)

25

(18.4)

Aetiology

< 0.001

 Perforation

59

(65.6)

34

(24.5)

 Ischaemia

20

(22.2)

19

(13.7)

 Anastomotic leakage

0

(0)

35

(25.2)

 Po with no lesion found

0

(0)

28

(20.6)

 Po abscess

0

(0)

6

(4.3)

 Trauma

8

(8.9)

5

(3.6)

 Other

3

(3.4)

9

(6.5)

  APACHE II

21

[15–25]

21

[15–24]

0.63

  MPI

23

[16–28]

24

[17–28]

0.24

  Mechanical ventilation > 24 h, n (%)

61

(67.8)

107

(78.7)

0.052

  Norepinephrine, n (%)

63

(70.0)

106

(78.0)

0.12

  Plasma creatinine level > 150 μmol/L, n (%)

41

(45.6)

63

(46.3)

0.89

  PT < 50%, n (%)

23

(25.6)

38

(28.0)

0.66

  Platelet < 50,000 /mm³, n (%)

16

(17.8)

15

(11.0)

0.16

  Renal replacement therapy, n (%)

25

(27.8)

50

(36.8)

0.15