Table 2 Clinical characteristics of patients with early, late and no acute kidney injury

Age (years)

57 (49–61)

56 (50–65)

60 (47–67)

0.55

Males

31 (76)

22 (63)

8 (53)

0.23

BMI (kg/m²)

33.2 (28.7–38.1)

30.8 (26.1–34.9)

29.3 (26.8–33.3)

0.15

Charlson comorb. index, pts

1 (0–2)

1 (0–1)

0 (0–1.5)

0.23

Disease severity

 SAPS II (pts.)

45 (36–55)

36 (31–41)

38 (34–42)

 < 0.001

 SOFA—admission (pts.)

14 (12–16)

10 (7–12)

12 (11–12)

 < 0.001

 SOFA—24h (pts.)

15 (13–16)

11 (8–12)

11 (10–12)

 < 0.001

ICU procedures

 Vasopressors

41 (100)

35 (100)

15 (100)

1

 High Flow-Nasal-Cannula

13 (32)

16 (46)

6 (40)

0.45

 Non-Invasive Ventilation

17 (41)

17 (49)

8 (53)

0.69

 Mechanical ventilation

41 (100)

35 (100)

15 (100)

1

 Renal Replacement Therapy

38 (93)

26 (74)

0 (0)

 < 0.001

COVID-19 Therapy

 Remdesivir

5 (12)

5 (14)

3 (20)

0.76

 Dexamethasone

28 (68)

30 (86)

13 (87)

0.13

 Plasma-Exchange

0 (0)

1 (3)

1 (7)

0.30

 Tocilizumab

1 (2)

1 (3)

1 (7)

0.72

 Other Antibody-Therapy

0 (0)

0 (0)

0 (0)

–

ARDS—Management

 Prone positioning

29 (71)

28 (80)

9 (60)

0.33

 Neuromuscular blockade

28 (68)

20 (57)

9 (60)

0.59

 Inhaled nitric oxide

24 (59)

19 (54)

7 (47)

0.73

 Glucocorticoid therapy

38 (93)

32 (91)

12 (80)

0.35

Complications—ICU stay

 Pulmonary embolism

2 (5)

7 (20)

0 (0)

0.03

 Deep vein thrombosis

4 (10)

4 (11)

0 (0)

0.41

 Cardiac arrest

12 (29)

11 (31)

4 (27)

0.94

 Neurologic

21 (51)

11 (31)

7 (47)

0.21

Urine output, fluid balance and blood gas

 Lactate, mmol/l—admission

1.8 (1.2–2.8)

1.4 (0.8–1.7)

1.7 (1.2–2.3)

 < 0.01

 pH, level—admission

7.30 (7.25–7.36)

7.39 (7.29–7.46)

7.39 (7.25–7.49)

 < 0.01

 Base excess—admission

− 0.7 (− 4.9–3.9)

4.4 (0.8–8.8)

5.3 (3.0–8.1)

 < 0.01

 Bicarbonate—admission

23 (20–27)

27 (24–31)

28 (26–30)

 < 0.01

 Creatinine, mg/dl—admission

1.79 (1.13–2.78)

0.8 (0.6–1.1)

0.83 (0.66–1.25)

 < 0.001

 Urine output, ml—day 1

455 (50–830)

1250 (690–1970)

1220 (535–1840)

 < 0.01

 Fluid balance, ml—day 1

1817 (360–3644)

300 (-242–648)

560 (98–2011)

 < 0.001

 Urine output, ml—day 2

600 (140–1510)

2230 (1523–3143)

2910 (1733–3223)

 < 0.001

 Fluid balance, ml—day 2

2245 (1141–4273)

722 (216–1743)

977 (183–1667)

 < 0.001

 Urine output, ml—day 3

183 (63–1042)

2390 (1975–3585)

2790 (2340–3070)

 < 0.001

 Fluid balance, ml—day 3

1978 (246–3459)

74 (− 391–1212)

540 (-432–1480)

 < 0.001

 Percentage of Fluid Overload

5.4 (3.0–8.2)

− 0.9 (− 3.3–0.6)

− 0.5 (− 2.3–1.1)

 < 0.001

Outcome

 Length of stay—ICU (days)

26 (15–57)

46 (34– 63)

21 (14–48)

0.05

 Length of stay—hospital (days)

30 (17–63)

43 (28–59)

26 (15–57)

0.07

 28-day mortality

18 (44)

9 (25)

8 (53)

0.12

 90-day mortality

27 (66)

22 (63)

8 (53)

0.69