Table 1 Comparisons of demographic data and clinical parameters among the whole cohort as well as early, and late RRT groups (n = 370)

Demographic data

Age (years)

65.4 ± 15.9

64.1 ± 16.5

66.7 ± 15.2

0.34

Male (%)

248 (67.0)

119 (62)

129 (72.5)

0.04

DM (%)

126 (34.1)

63 (32.8)

63 (35.5)

0.68

Hypertension(%)

175 (47.3)

92 (47.9)

83 (46.6)

0.93

CHF (%)

68 (18.4)

44 (22.9)

24 (13.5)

0.02

CKD (%)

92 (24.9)

56 (29.2)

36 (20.2)

0.06

Post-operative (%)

237 (64.1)

113 (58.9)

124 (69.7)

0.03

Admission creatinine (mg/dL)

2.0 ± 0.2

2.7 ± 1.7

1.5 ± 1.0

< 0.01

   (μmol/L)

176.6 ± 17.7

238.7 ± 150.3

132.6 ± 88.4

Mechanical ventilation (%)

322 (87.0)

163 (84.9)

159 (89.3)

0.27

Data at ICU admission

Hematocrit (%)

32.2 ± 9.5

32.3 ± 12.0

32.1 ± 5.9

0.83

BUN (mg/dL)

50.7 ± 33.7

59.8 ± 34.1,

41.0 ± 30.4,

0.05

   (mmol/L)

18.1 ± 12.0

21.3 ± 12.2

14.6 ± 10.9

Creatinine (mg/dL)

2.5 ± 1.7

2.6 ± 1.8

2.3 ± 1.6

0.06

   (μ mol/L)

221 ± 150.3

232.5 ± 156.5

200.7 ± 141.4

Albumin (g/dL)

2.9 ± 0.7

3,0 ± 0.7

2.9 ± 0.7

0.08

   (g/L)

29 ± 7

30 ± 7

29 ± 7

APACHE II scores

11.3 ± 6.4

11.8 ± 6.6

10.7 ± 6.0

0.37

SOFA scores

8.1 ± 3.8

8.7 ± 3.7

7.4 ± 3.8

0.18

SAPS III score

63.1 ± 13.0

64.7 ± 7.3

62.2 ± 7.6

0.30

Pre-RRT data

Hematocrit (%)

30.0 ± 5.8

30.1 ± 6.3

29.8 ± 0.6

0.62

BUN (mg/dL)

81 ± 40.6

78.2 ± 41.2

84.0 ± 39.8

0.19

   (mmol/L)

28.9 ± 14.5

27.9 ± 14.7

30.0 ± 14.2

Creatinine (mg/dL)

3.4 ± 0.4

3.4 ± 0.3

3.4 ± 0.8

0.17

   (μmol/L)

298.8 ± 35.4

297.9 ± 23.9

299.7 ± 70.7

Albumin (g/dL)

3.0 ± 1.2

3.1 ± 1.5

2.9 ± 0.6

0.09

   (g/L)

30 ± 12

31 ± 15

29 ± 6

Potassium (mEq/L)

4.8 ± 12.1

5.0 ± 1.0

4.3 ± 0.9

0.32

Lactate (mg/dL)

3.4 ± 3.6

3.5 ± 3.9

3.1 ± 3.5

0.10

   (mmol/L)

0.4 ± 0.4

0.4 ± 0.4

0.3 ± 0.4

GCS scores

11.8 ± 3.7

11.5 ± 4.3

11.0 ± 4.5

0.72

Systolic blood pressure

122.7 ± 25.7

122.8 ± 26.5

123.7 ± 25.7

0.84

Diastolic blood pressure

61.2 ± 39.0

61.5 ± 14.1

60.1 ± 14.0

0.36

Central venous pressure

13.8 ± 5.5

14.16 ± 5.9

13.4 ± 5.2

0.22

APACHE II scores

13.1 ± 6.4

12.3 ± 7.0

14.0 ± 5.5

0.52

SOFA scores

11.2 ± 3.9

10.8 ± 4.0

11.6 ± 3.7

0.80

SAPS III score

67.3 ± 6.8

66.2 ± 6.7

68.6 ± 6.7

0.61

Indications for dialysis

Azotemia with uremic symptoms

265 (71.6)

119 (62.0)

146 (82.0)

< 0.01

Oligouria or anuria

241 (65.1)

113 (58.9)

128 (63.0)

0.01

Fluid overload

81 (21.9)

41 (21.4)

40 (22.5)

0.29

Electrolyte imbalance

23 (6.2)

8 (4.2)

15 (8.4)

0.14

Acid base imbalance

25 (6.8)

12 (6.4)

13 (7.3)

0.84

Rhabdomyolysis

7 (1.9)

5 (2.7)

2 (1.1)

0.51

Hospital mortality

259 (70.0)

135 (70.8)

124 (69.7)

0.98