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Table 2 Summary of patients’ characteristics at baseline, preoperative and intraoperative measures

From: Fluid balance, change in serum creatinine and urine output as markers of acute kidney injury post cardiac surgery: an observational study

 

All (n = 111)

SCr-, UO-, FOL- (n = 43)

SCr-, UO-, FOL + (n = 32)

SCr-, UO+, FOL- (n = 11)

SCr-, UO+, FOL + (n = 15)

SCr + (n = 10)

P-value

Demographics

       

Age (years)

69 ± 10

69 ± 9

73 ± 8

60 ± 14

68 ± 11

69 ± 11

0.03

Male

84 (76%)

36 (84%)

21 (66%)

9 (82%)

11 (73%)

7 (70%)

0.43

Diabetes

31 (28%)

10 (23%)

4 (12%)

5 (45%)

6 (40%)

6 (60%)

0.01

Preoperative Measures

       

Weight (kg)

80 (68, 91)

80 (71, 92)

69 (64, 84)

84 (78, 111)

85 (79, 93)

92 (68, 107)

0.01

Height (cm)

170 ± 10

170 ± 10

169 ± 11

172 ± 8

171 ± 10

170 ± 12

0.94

Creatinine (μmol/L)

85 (71, 103)

87 (69, 101)

80 (71, 93)

81 (70, 103)

88 (70, 96)

117 (90, 144)

0.01

eGFR (mL/min/1.73 m2)

72 ± 17

77 ± 23

73 ± 19

81 ± 23

63 ± 28

52 ± 18

0.01

eGFR <60 mL/min/1.73 m2

28 (25%)

8 (19%)

7 (23%)

2 (18%)

4 (27%)

7 (70%)

0.03

Recent IV Contrast

57 (51%)

15 (35%)

21 (64%)

5 (45%)

9 (60%)

7 (70%)

0.05

Pre-op ACE/ARB

73 (66%)

27 (63%)

20 (62%)

9 (82%)

11 (73%)

6 (60%)

0.72

Pre-op Diuretics

31 (28%)

11 (25%)

6 (19%)

3 (27%)

5 (33%)

6 (60%)

0.16

Surgery Type

       

MVR Only/AVR Only

35 (32%)

12 (28%)

13 (41%)

2 (18%)

4 (27%)

4 (40%)

0.17

CABG Only

59 (53%)

28 (65%)

13 (41%)

8 (73%)

6 (40%)

4 (40%)

 

CABG + MVR/AVR

17 (15%)

3 (7%)

6 (18%)

1 (9%)

5 (33%)

2 (20%)

 

Intraoperative Measures

       

Duration of Surgery (mins)

177 (146, 209)

188 (150, 209)

156 (122, 190)

176 (117, 200)

186 (151, 233)

200 (173, 243)

0.007

CPB Time (mins)

92 (72, 108)

92 (77, 105)

75 (62, 96)

84 (46, 100)

103 (88, 148)

103 (95, 140)

0.01

Intraoperative pRBC

24 (22%)

6 (12%)

9 (25%)

1 (0%)

7 (40%)

6 (50%)

0.007

Intraoperative Crystalloid (cc)

1260 (875, 1727)

1200 (900, 1780)

1350 (900, 1663)

850 (700, 1260)

1050 (845, 1650)

1386 (1000, 1880)

0.43

Intraoperative Colloid (cc)

500 (500, 500)

500 (500, 650)

500 (500, 600)

500 (500, 500)

500 (500, 500)

500 (500, 500)

0.54

Total Fluid Administered (cc)

1850 (1485, 2380)

1820 (1500, 2380)

1901 (1715, 2398)

1350 (1100, 1960)

1730 (1520, 2404)

2165 (1600, 3412)

0.08

Total Urine Output (cc)

250 (160, 400)

325 (175, 500)

250 (187, 470)

220 (150, 350)

260 (125, 400)

125 (70, 225)

0.07

Total Fluid Balance (cc)

129 (846, 1700)

1350 (900, 1720)

1147 (875, 1519)

1240 (515, 1825)

1200 (−686, 1650)

1765 (105, 2003)

0.68

Negative Fluid Balance at Completion of Surgery

8 (7%)

1 (2%)

0 (0%)

0 (0%)

5 (33%)

2 (20%)

<0.001

Postoperative Medications

      

Vasopressors

85 (77%)

29 (67%)

27 (84%)

6 (54%)

13 (87%)

10 (100%)

0.04

Number of Vasopressors

1 (1, 2)

1 (0, 1)

1.5 (1, 2)

1 (0, 2)

2 (1, 2)

2.5 (2, 4)

<0.001

  1. Vasopressors used were: Adrenaline, noradrenaline, dobutamine, milirinone and vasopressin.
  2. SCr+: Meeting the criteria of Change in SCr ≥ 26.5 µmol/L ; SCr -: Not meeting the Change in SCr criteria.
  3. UO+: Meeting the criteria of Urine Output ≤0.5 cc/kg/hour for greater than 6 hours; UO-: Not meeting the Urine Output criteria.
  4. FOL+: Meeting the criteria of Fluid Overload, defined as fluid balance ≥ 6.5 cc/kg; FOL-: Not meeting the Fluid Overload criteria.
  5. Continuous variables are presented in mean ± standard deviation or median with interquartile range. Categorical variables are presented in count with percentage. One-way ANOVA or Kruskal-Wallis test were used to compare among groups for the continuous variables; Chi-Square test or Fisher’s Exact test were used for the categorical variables.
  6. eGFR was calculated using the MDRD equation.