Table 1 Clinical characteristics, hemodynamic variables and biochemical data with simultaneous measurements of skeletal muscle rSO₂ of 40 patients included

Demographic data

 Age (years), mean (SD)

55.5 (15.9)

53 (16.4)

65 (9.8)*

 Male, n (%)

27 (67.5)

21 (65.6)

6 (75.0)

Severity of illness

 APACHE II score at day 1, median (IQR 25–75)

17 (12–21)

16 (12–20)

22 (18–34)**

 SOFA score at day 1, median (IQR 25–75)

4 (3–5)

4 (3–5)

4 (3–8)

 Major ATS criteria, median (IQR 25–75)

28 (70)

20 (62.5)

8 (100)**

 Invasive mechanical ventilation, n (%)

21 (52.5)

13 (40.6)

8 (100)***

 Severe sepsis, n (%)

18 (44.5)

17 (53.1)

1 (12.5)

 Septic shock, n (%)

22 (55.5)

15 (46.9)

7 (87.5)*

Mean comorbidities, n (%)

 Tobacco use

3 (8.6)

3 (10.7)

0

 Chronic obstructive pulmonary disease

12 (33.3)

10 (34.3)

2 (28.6)

 Cardiac disease

8 (20)

6 (18.7)

2 (28.6)

 Diabetes mellitus

7 (20)

5 (17.9)

2 (28.6)

 Severe liver disease

1 (2.9)

0

1 (14.3)

Hemodynamic data, median (IQR 25–75)

 Heart rate, b/min

105 (86–114)

105 (87–114)

105 (85–113)

 Heart rate at 24 h

90 (77–100)

92 (79–103)

85 (70–99)

 Mean arterial pressure, mmHg

79 (71–94)

78 (72–98)

80 (69–88)

 Mean arterial pressure at 24 h

79 (70–93)

76 (70–96)

79 (71–90)

 Central venous pressure, mmHg

11 (9–15)

11 (8–15)

11 (10–14)

 Central venous pressure at 24 h

13 (13–16)

11 (7–16)

14 (12–15)

 Mixed venous oxygen saturation, %^a

76 (70–79)

76 (69–79)

74 (74)

 Mixed venous oxygen saturation at 24 h^a

70 (68–83)

70 (68–80)

80 (70–91)

Biochemical data, mean (SD)

 Baseline serum lactate, mM/L

3.0 (3.1)

2.5 (1.6)

4.8 (6.1)

 Serum lactate at 24 h

2.0 (2.2)

1.4 (0.6)

3.9 (4.0)

 Baseline base deficit

−3.5 (5.2)

−3.6 (5.4)

−2.7 (4.3)

 Base deficit at 24 h

−2.3 (4.1)

−1.9 (4.1)

−3.4 (4.2)

 Baseline haemoglobin levels, mg %

11.9 (1.8)

12.1 (1.9)

11.2 (1.1)

 Haemoglobin levels at 24 h

10.6 (1.7)

10.6 (1.9)

10.4 (1.1)

 Baseline serum glucose, mg %

166 (74.7)

158 (75.3)

197 (66.8)

 Serum glucose at 24 h

152 (75.6)

144 (79.4)

177 (58.7)

 Baseline arterial pH

7.34 (0.1)

7.40 (0.1)

7.34 (0.3)

 Arterial pH at 24 h

7.36 (0.07)

7.30 (0.07)

7.32 (0.1)

 Baseline serum creatinine, mg %

1.40 (0.9)

1.38 (1.03)

1.41 (0.8)

 Serum creatinine at 24 h

1.1 (0.59)

0.9 (0.4)

1.5 (0.9)

rSO₂ brachioradialsis

 Baseline rSO₂, mean (SD)

62.9 (10.7)

68 (61–72)

46 (43–57)***

 rSO₂ at 24 h, mean (SD)

65.4 (12.3)

69 (60–76)

52 (41–57)***

 Baseline rSO₂ < 60, n (%)

14 (35)

7 (21.9)

7 (87.5)***

 rSO₂ < 60 at 24 h, n (%)

6 (15.8)

4 (12.5)

7 (87.5)***

Therapy, mean (SD)

 Norepinephrine at baseline μg/kg/min

0.35 (0.26)

0.40 (0.14)

0.29 (0.36)

 Norepinephrine at 24 h, μg/kg/min

0.35 (0.29)

0.22 (0.28)

0.52 (0.23)*

 Fluid balance at 24 h, mL

1650 (1350)

1470 (800)

2300 (2500)

ICU length of stay

 Median IQR 25–75 %

18 (11–30)

18 (11–31)

24 (8–30)