Table 2.
Baseline cardiovascular and respiratory parameters of all the cases at the time of inclusion
| Studied variables | All cases (n = 84) |
Non-responsive cases (n = 42) |
Responsive cases (n = 42) |
p value |
|---|---|---|---|---|
| Inclusion time after admission (days) | 7 (4–11) | 8 (5–15) | 6 (3–10) | 0.145 |
| Inclusion time after prone positioning (hours) | 11 (2–14) | 12 (5–15) | 8 (1–12) | 0.033 |
| Hemodynamic variables | ||||
| Number of patients with norepinephrine (n, %) | 70 (83) | 35 (83) | 35 (83) | 0.770 |
| Dose of norepinephrine (µg/kg/min) | 0.25 (0.15–0.42) | 0.23 (0.14–0.35) | 0.32 (0.17–0.56) | 0.382 |
| Heart rate (beats/min) | 83 (69–100) | 82 (67–94) | 94 (74–107) | 0.014 |
| Systolic arterial pressure (mmHg) | 127 ± 18 | 127 ± 18 | 127 ± 18 | 1.000 |
| Diastolic arterial pressure (mmHg) | 59 ± 10 | 57 ± 8 | 60 ± 11 | 0.131 |
| Mean arterial pressure (mmHg) | 82 ± 12 | 82 ± 11 | 83 ± 13 | 0.594 |
| Central venous pressure (mmHg) | 10 ± 4 | 11 ± 5 | 8 ± 4 | 0.012 |
| Intra-abdominal pressure (mmHg) | 11 ± 4 | 11 ± 4 | 11 ± 4 | 0.924 |
| CITPTD (L/min/m2) | 3.06 ± 0.90 | 3.38 ± 0.95 | 2.73 ± 0.74 | 0.001 |
| GEDVI (mL/m2) | 744 ± 173 | 780 ± 202 | 708 ± 130 | 0.055 |
| EVLW (mL/kg) | 17 (15–20) | 17 (15–20) | 17 (14–21) | 0.936 |
| PVPI | 3.4 (2.9–4.1) | 3.2 (2.6–4.1) | 3.5 (2.9–4.1) | 0.293 |
| Fluid balance of previous 24 h (mL) | 562 (-224–1660) | 500 (-183–1720) | 693 (-280–1717) | 0.831 |
| Lactate (mmol/L) | 1.6 (1.3–2.3) | 1.5 (1.1–1.8) | 2.1 (1.3–2.8) | 0.005 |
| Respiratory variables | ||||
| Respiratory rate (breaths/min) | 30 (26–33) | 30 (28–35) | 28 (25–30) | 0.035 |
| PaO2/FiO2 before prone positioning (mmHg) | 104 ± 27 | 105 ± 24 | 102 ± 29 | 0.684 |
| 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) | 0.267 |
| 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) | 0.321 |
| Total PEEP (cmH2O) | 14 (11–16) | 14 (12–16) | 14 (10–16) | 0.946 |
| Driving pressure before TVC (cmH2O) | 12 (10–17) | 13 (10–18) | 12 (10–17) | 0.723 |
| Plateau pressure before TVC (cmH2O) | 27 (25–31) | 27 (25–30) | 27 (25–31) | 0.882 |
| Crs before TVC (mL/cmH2O) | 32 (22–41) | 31 (21–39) | 34 (22–41) | 0.591 |
| Driving pressure at the end of TVC (cmH2O)* | 19 (15–22) | 19 (15–21) | 20 (15–24) | 0.473 |
| Plateau pressure at the end of TVC (cmH2O)* | 32 (29–37) | 33 (30–38) | 32 (28–35) | 0.229 |
| Crs at the end of TVC (mL/cmH2O)* | 28 (22–39) | 28 (24–39) | 27 (21–39) | 0.715 |
CI cardiac index, Crs compliance of the respiratory system, EVLW extravascular lung water, GEDVI global end-diastolic volume index, PVPI pulmonary vascular permeability index, PaO2/FiO2 the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen, PBW predicted body weight, PEEP positive end-expiratory pressure, TPTD transpulmonary thermodilution, TVC tidal volume challenge; Bold font indicates statistical significance
*Available in 78 cases