Table 1 Preoperative and intraoperative factors for patients who had a postoperative evaluation of serum creatinine available for PO-AKI detection (PO-SCr-available) and for patients who did not (SCr result not available). In those patients for whom postoperative serum creatinine was measured, preoperative and intraoperative variables statistically associated with PO-AKI have been evaluated through univariate analysis. For qualitative data with more than two levels (e.g. type of surgery), the Wald test was used to provide an overall p value. For the numbers of preoperative risk factors for AKI, n<2 is used as a reference for the other levels, and videolaparoscopic is used for the other surgical approaches. The results are presented as OR [95%CI] and p value

Male gender

32 (54.2%)

186 (51.1%)

164 (49.1%)

22 (73.3%)

2.85 [1.23; 6.58]

0.013

Age (yrs)

67.6 [52.4–76.1]

70.2 [60.5–78.1]

70.1 [60.1–77.7]

77.53 [68.9–82.2]

1.03 [1.00; 1.07]

0.018

Baseline SCr (mg/dl)

0.83 [0.66–1.02]

0.83 [0.71–0.99]

0.81 [0.68–0.97]

1.06 [0.82–1.38]

2.55 [1.31; 4.96]

<0.001

Baseline eGFR (ml/min/1.73 m²)

81.9 [73.2–97.4]

81.4 [68.1–93.5]

81.9 [69.1–93.9]

67.6 [45.1–82.9]

0.97 [0.95; 0.98]

<0.001

Comorbidities

 Diabetes

3 (5.1%)

56 (15.4%)

49 (14.7%)

7 (23.3%)

1.77 [0.72; 4.35]

0.196

 Hypertension

22 (37.3%)

181 (49.7%)

162 (48.5%)

19 (63.3%)

1.83 [0.85; 3.97]

0.131

 Vascular disease

5 (8.5%)

47 (12.9%)

39 (11.7%)

8 (26.7%)

2.75 [1.15; 6.6]

0.040

 Previous solid neoplasm

40 (67.8%)

231 (63.5%)

213 (63.7%)

18 (60%)

0.75 [0.28; 2.04]

0.814

 Previous haematologic neoplasm

1 (1.7%)

6 (1.7%)

6 (1.8%)

0

–

–

 Chronic heart failure

2 (3.4%)

50 (13.7%)

43 (12.9%)

7 (23.3%)

2.06 [0.83; 5.09]

0.159

 Preop nephrotoxic drugs

16 (27.1%)

144 (39.6%)

126 (37.7%)

18 (60%)

2.48 [1.15; 5.31]

0.020

 CKD

4 (6.8%)

61 (16.8%)

47 (14.1%)

14 (46.7%)

5.34 [2.45; 11.7]

<0.001

Number of preop risk factors for AKI

0.010

 <2

38 (64.4%)

172 (47.3%)

174 (52.1%)

7 (23.3%)

ref.

 >2

13 (22.0%)

74 (20.3%)

66 (19.8%)

8 (26.7%)

2.76 [0.80–9.54]

0.109

 >3

5 (8.5%)

65 (17.9%)

59 (17.7%)

6 (20.0%)

2.31 [0.63–8.55]

0.208

 >4

3 (5.1%)

30 (8.2%)

26 (7.8%)

4 (13.3%)

3.50 [0.82–15.0]

0.091

 >5

0

13 (3.6%)

8 (2.4%)

5 (16.7%)

14.20 [3.17–63.7]

<0.001

 >6

0

1 (0.3%)

1 (0.3%)

0

–

–

Type of surgery

 Colorectal

38 (64.4%)

255 (70.1%)

235 (70.4%)

20 (66.7%)

1.25 [0.52; 3.01]

0.831

 Gastric

9 (15.3%)

31 (8.5%)

29 (8.7%)

2 (6.7%)

0.67 [0.15; 2.96]

1.000

 Oesophageal

0

9 (2.5%)

8 (2.4%)

1 (3.3%)

1.41 [0.17; 11.6]

0.543

 Hepatic

1 (1.7%)

16 (4.4%)

16 (4.5%)

0

–

–

 Pancreatic

3 (5.1%)

19 (5.2%)

17 (5.1%)

2 (6.7%)

1.33 [0.29; 6.06]

0.663

 Others

8 (13.6%)

31 (8.5%)

26 (7.8%)

5 (16.7%)

3.34 [1.43; 7.82]

0.08

Surgical approach

0.67

 Videolaparoscopy

27 (45.7%)

134 (36.8%)

125 (37.4%)

9 (30%)

ref.

 Laparotomy

27 (45.7%)

201 (55.2%)

183 (54.8%)

18 (60%)

1.36 [0.59; 3.13]

0.46

 Robotic surgery

5 (8.5%)

29 (8%)

25 (7.5%)

4 (13.3%)

1.72 [0.43; 6.83]

0.44