Table 2 Baseline cardiovascular and respiratory parameters of all the cases at the time of inclusion

Inclusion time after admission (days)

7 (4–11)

8 (5–15)

6 (3–10)

Inclusion time after prone positioning (hours)

11 (2–14)

12 (5–15)

8 (1–12)

Hemodynamic variables

Number of patients with norepinephrine (n, %)

70 (83)

35 (83)

35 (83)

Dose of norepinephrine (µg/kg/min)

0.25 (0.15–0.42)

0.23 (0.14–0.35)

0.32 (0.17–0.56)

Heart rate (beats/min)

83 (69–100)

82 (67–94)

94 (74–107)

Systolic arterial pressure (mmHg)

127 ± 18

127 ± 18

127 ± 18

Diastolic arterial pressure (mmHg)

59 ± 10

57 ± 8

60 ± 11

Mean arterial pressure (mmHg)

82 ± 12

82 ± 11

83 ± 13

Central venous pressure (mmHg)

10 ± 4

11 ± 5

8 ± 4

Intra-abdominal pressure (mmHg)

11 ± 4

11 ± 4

11 ± 4

CI_TPTD (L/min/m²)

3.06 ± 0.90

3.38 ± 0.95

2.73 ± 0.74

GEDVI (mL/m²)

744 ± 173

780 ± 202

708 ± 130

EVLW (mL/kg)

17 (15–20)

17 (15–20)

17 (14–21)

PVPI

3.4 (2.9–4.1)

3.2 (2.6–4.1)

3.5 (2.9–4.1)

Fluid balance of previous 24 h (mL)

562 (-224–1660)

500 (-183–1720)

693 (-280–1717)

Lactate (mmol/L)

1.6 (1.3–2.3)

1.5 (1.1–1.8)

2.1 (1.3–2.8)

Respiratory variables

Respiratory rate (breaths/min)

30 (26–33)

30 (28–35)

28 (25–30)

PaO₂/FiO₂ before prone positioning (mmHg)

104 ± 27

105 ± 24

102 ± 29

Tidal volume before TVC (mL/kg PBW)

6.0 (6.0–6.0)

6.0 (6.0–6.0)

6.0 (6.0–6.0)

Tidal volume during TVC (mL/kg PBW)

8.0 (8.0–8.0)

8.0 (8.0–8.0)

8.0 (8.0–8.0)

Total PEEP (cmH₂O)

14 (11–16)

14 (12–16)

14 (10–16)

Driving pressure before TVC (cmH₂O)

12 (10–17)

13 (10–18)

12 (10–17)

Plateau pressure before TVC (cmH₂O)

27 (25–31)

27 (25–30)

27 (25–31)

Crs before TVC (mL/cmH₂O)

32 (22–41)

31 (21–39)

34 (22–41)

Driving pressure at the end of TVC (cmH₂O)*

19 (15–22)

19 (15–21)

20 (15–24)

Plateau pressure at the end of TVC (cmH₂O)*

32 (29–37)

33 (30–38)

32 (28–35)

Crs at the end of TVC (mL/cmH₂O)*

28 (22–39)

28 (24–39)

27 (21–39)