Table 2 Univariate analysis of intraoperative and postoperative data associated with the presence of AKI after cardiac surgery

Intraoperative data

Isolated CABG

32.1% (945)

33.6% (851)

23.0% (94)

0.005

Isolated valve surgery

51.6% (1,518)

51.8% (1,311)

51.6% (207)

0.85

CABG + valve surgery

6.9% (203)

6.2% (158)

11.0% (45)

<0.001

Other cardiac surgery

9.4% (274)

8.4% (211)

15.4% (63)

<0.001

Emergent surgery

5.1% (149)

3.9% (99)

12.2% (50)

<0.001

Number of bypass

2.3 ±0.9

2.3 ± 0.8

2.2 ± 0.9

0.68

ACC time (minutes)

73 ± 29

72 ± 28

87 ± 37

<0.001

CPB time (minutes)

113 ± 41

109 ± 37

135 ± 55

<0.001

Postoperative data

Ventilation time (hours)

50 ± 127

36 ± 96

139 ± 229

<0.001

PaO₂/FiO₂ ratio on admission

331 ± 98

334 ± 96

315 ± 106

0.001

PaO₂/FiO₂ ratio 12 h after admission

311 ± 89

316 ± 87

278 ± 93

<0.001

PaO₂/FiO₂ ratio 24 h after admission

307 ± 77

314 ± 72

270 ± 90

<0.001

Reintubation

1.1% (31)

0.8% (21)

2.5% (10)

0.001

Tracheostomy

1.3% (38)

0.8% (19)

4.7% (19)

0.001

Need of vasoactive drugs (hours)

103 ± 141

82 ± 110

195 ± 210

<0.001

LCOS

41.6% (1,223)

36.3% (920)

74.1% (303)

<0.001

PMI

11.8% (346)

10% (252)

23% (94)

<0.001

IABP support

7.8% (230)

6.1% (155)

18.3% (75)

<0.001

Atrial fibrilation

39.4% (1,158)

36.1% (913)

59.9% (245)

<0.001

AL on admission (mmol · L^-1)

2.3 ± 1.4

2.2 ± 1.2

3.1 ± 2.3

<0.001

AL 24 h after admission (mmol · L^-1)

1.9 ± 1.0

1.8 ± 0.7

2.6 ± 1.9

<0.001

sCr peak after surgery (mmol · L^-1)

114.3 ± 80.8

99.0 ± 62.0

205.0 ± 113.0

<0.001

Albumin 48 h after surgery (g · L^-1)

28.2 ± 3.7

28.4 ± 3.6

26.5 ± 4.1

<0.001

Hemorrhage-related re-exploration

3.5% (103)

2.6% (66)

9.0% (37)

<0.001

Pericardial tamponade

0.7% (22)

0.4% (11)

2.7% (11)

<0.001

Drainage loss first 12 h (mL)

393 ± 301

377 ± 275

496 ± 414

<0.001

Major bleeding

3.6% (109)

2.6% (66)

10.5% (43)

<0.001

Re-exploration

1.6% (48)

0.8% (21)

5.1% (27)

<0.001

Need for blood products (units)

1.6 ± 3.0

1.4 ± 2.5

3.3 ± 4.6

<0.001

Stroke

1.4% (42)

0.9% (24)

4.4% (18)

<0.001

Septicemia

6.6% (195)

4.0% (102)

22.7% (93)

<0.001

SAPS II

24.2 ± 9.6

22.8 ± 8.3

32.3 ± 12.8

<0.001

SAPS III

39.9 ± 10.4

38.6 ± 9.4

48.4 ± 12.3

<0.001

APACHE II

12.3 ± 4.6

11.6 ± 4.0

16.1 ± 6.3

<0.001

APACHE III

49.9 ± 18.5

47.0 ± 15.0

67.0 ± 24.0

<0.001

Mean Pre-ICU stay (days)

7.0 ± 13.0

6.7 ± 8.6

8.7 ± 28.8

0.15

Mean ICU stay (days)

7.5 ± 11.0

6.2 ± 7.7

15.2 ± 20.3

<0.001

Mean hospital stay (days)

24.6 ± 22.5

22.8 ± 15.7

36.1 ± 44.5

<0.001

In-hospital mortality

6.0% (177)

2.4% (60)

28.6% (117)

<0.001