Table 1 Demographic, clinical and ventilatory characteristics of patients according to their proning status at Day-1
Variable | All patients (n = 2137) | Non-early prone position group (n = 1646) | Early prone position group (n = 491) | p |
|---|---|---|---|---|
Age (years), median (IQR) | 63 (55–70) | 63 (55–70) | 63 (54–70) | 0.393 |
Sex, n (%) | ||||
Men | 1598 (75.1%) | 1242 (75.7%) | 356 (73.1%) | 0.238 |
Women | 529 (24.9%) | 398 (24.3%) | 131 (26.9%) | |
Body mass index (kg/m2), median (IQR) | 29 (26–33) | 28 (26–32) | 30 (27–34) | < 0.0001 |
≥ 30 kg/m2, n (%) | 888 (44.4%) | 636 (41.4%) | 252 (54.8%) | < 0.0001 |
Comorbidities, n (%) | ||||
Active smokers | 87 (4.2%) | 68 (4.3%) | 19 (4%) | 0.791 |
Treated hypertension | 1055 (49.9%) | 786 (48.3%) | 269 (55.2%) | 0.005 |
Known diabetes | 601 (28.4%) | 446 (27.4%) | 155 (31.9%) | 0.053 |
Immunodeficiency | 154 (7.3%) | 120 (7.4%) | 34 (7%) | 0.788 |
Long-term corticosteroids | 77 (3.7%) | 66 (4.1%) | 11 (2.3%) | 0.064 |
SAPS II score, median (IQR) | 43 (32–56) | 42 (32–56) | 44 (32–55) | 0.702 |
SOFA score at ICU admission, median (IQR) | 7 (4–10) | 7 (4–10) | 8 (5–10) | 0.033 |
Clinical frailty score, median (IQR) | 2 (2–3) | 2 (2–3) | 2 (2–3) | 0.112 |
Time between first symptoms and ICU admission (days), median (IQR) | 9 (6–12) | 9 (6–12) | 9 (6–11) | 0.273 |
Time between ICU admission and invasive mechanical ventilation (hours), median (IQR) | 2.7 (0.7–9.7) | 3 (0.7–10.8) | 1.8 (0.4–6.3) | 0.001 |
Concomitant bacterial pneumonia, n (%) | 130 (6.3%) | 93 (5.8%) | 37 (7.7%) | 0.143 |
Respiratory support received in ICU before intubation at Day-1, n (%) | ||||
Oxygen therapy | 220 (10.3%) | 177 (10.8%) | 43 (8.8%) | 0.203 |
High-flow nasal cannula | 143 (6.8%) | 119 (7.3%) | 24 (4.9%) | 0.069 |
Non-invasive mechanical ventilation | 61 (2.9%) | 43 (2.3%) | 18 (3.7%) | 0.216 |
High-doses Corticosteroids using at Day-1 n (%) | 227 (10.7%) | 171 (10.5%) | 56 (11.4%) | 0.557 |
Invasive mechanical ventilation settings, median (IQR) | ||||
PaO2/FiO2 (mmHg) | 145.7 (101.7–200) | 152.2 (107–205) | 128.3 (87.5–177.5) | < 0.0001 |
Tidal volume (mL) | 415 (375–450) | 418 (380–450) | 400 (370–440) | 0.0035 |
Tidal volume, mL/kg PBW | 6.1 (5.8–6.7) | 6.1 (5.8–6.7) | 6.1 (5.8–6.5) | 0.1326 |
Set PEEP (cmH2O) | 12 (10–14) | 12 (10–14) | 12 (10–14) | < 0.0001 |
Plateau pressure (cmH2O) | 24 (21–27) | 24 (21–27) | 25 (22–28) | < 0.0001 |
Driving pressure1 (cmH2O) | 13 (10–17) | 13 (10–17) | 13.5 (11–17) | 0.0345 |
Mechanical power2 (J/min) | 26.7 (18.9–35) | 25.8 (18.4–33.6) | 30.3 (21.1–39.1) | < 0.0001 |
Ventilatory ratio3 (J/min) | 1.7 (1.4–2.2) | 1.7 (1.4–2.1) | 1.9 (1.5–2.4) | < 0.0001 |
Static compliance4 (mL/cmH2O) | 32.8 (26.3–41.7) | 33.6 (26.9–42) | 30.7 (24.1–39.9) | 0.001 |
Dynamic compliance5 (mL/cmH2O) | 16.7 (13.6–21) | 17 (14.1–21.4) | 15.2 (12.3–19.5) | < 0.0001 |
Blood gas, median (IQR) | ||||
pH | 7.4 (7.3–7.4) | 7.4 (7.3–7.4) | 7.4 (7.3–7.4) | < 0.0001 |
PaCO2 (mmHg) | 43 (37–49) | 42 (37–48) | 45 (40–52) | < 0.0001 |
PaO2/FiO2 (mmHg) | 145.7 (101.7–200) | 152.2 (107–205) | 128.3 (87.5–177.5) | < 0.0001 |
< 150 mmHg, n (%) | 1106 (51.8%) | 796 (48.4%) | 310 (63.1%) | < 0.0001 |
HCO3 (mmol/L) | 25 (22–27) | 24 (22–27) | 25 (22–28) | 0.001 |
Lactate (mmol/L) | 1.3 (1–1.7) | 1.3 (1–1.7) | 1.3 (1–1.8) | 0.012 |
Biology, median (IQR) | ||||
Lymphocyte count (× 109/L) | 0.8 (0.5–1.1) | 0.8 (0.5–1.1) | 0.8 (0.6–1.2) | 0.294 |
Thrombocyte count (× 109/L) | 225 (167–292.5) | 223 (165–291) | 227 (170.2–296) | 0.367 |
Total bilirubin (mg/dL) | 0.58 (0.41–0.89) | 0.58 (0.41–0.89) | 0.58 (0.41–0.89) | 0.245 |
Serum creatinine (mg/dL) | 0.94 (0.71–1.39) | 0.92 (0.7–1.38) | 0.98 (0.74–1.46) | 0.033 |
D-dimer (µg/L) | 1913 (1100–4219) | 1844 (1038.5–4212.2) | 2220 (1237–4262) | 0.158 |
CRP (mg/L) | 186.4 (121.2–266.5) | 180 (119–261.4) | 202.4 (136.1–276) | 0.021 |
Procalcitonin (ng/mL) | 0.7 (0.3–2.2) | 0.6 (0.3–2) | 0.9 (0.4–2.9) | 0.01 |
hsTroponine T (ng/L) | 23 (12–63.2) | 22 (11.3–58.6) | 31.4 (14.1–95.2) | 0.003 |