Table 2.
Respiratory mechanics, arterial blood gases, and hemodynamics
| Parameters | Supine (n.20) | Recruitment (n.20) | Prone (n.20) | P value |
|---|---|---|---|---|
| Respiratory mechanics | ||||
| Respiratory system compliance (ml/cmH2O) | 38.5 (28.5–48.0) | 32.0 (27.0–45.0) | 37.0 (31.0–48.5) | 0.377 |
| Respiratory system driving pressure (cmH2O) | 13.0 (10.0–16.0) | 25.0 (23.0–25.0)a | 13.5 (9.8–16.0)b | < 0.001 |
| Plateau pressure (cmH2O) | 24.0 (20.0–27.0) | 35.0 (35.0–35.0)a | 24.0 (21.0–26.3)b | < 0.001 |
| Tidal volume (ml/kg) | 6.7 (6.4–7.0) | 11.2 (9.5–14.9)a | 6.6 (6.1–6.9)b | < 0.001 |
| Mechanical respiratory rate (breaths/min) | 22.0 (20.0–24.3) | 10.0 (10.0–10.0)a | 21.0 (20.0–24.3)b | < 0.001 |
| Arterial blood gases | ||||
| PaO2/FiO2 (mmHg) | 111.0 (80.3–139.0) | 114.0 (95.5–189.0)c | 156.0 (139.0–204.0)a,d | < 0.001 |
| PaCO2 (mmHg) | 57.0 (44.0–68.3) | 51.0 (43.5–56.0)a | 50.5 (42.8–61.0)e | < 0.001 |
| pH | 7.36 (7.28–7.39) | 7.39 (7.34–7.44)a | 7.37 (7.31–7.43)f | < 0.001 |
| Hemodynamics | ||||
| Mean arterial pressure (mmHg) | 88.0 (74.0–93.3) | 80.0 (72.5–87.0) | 82.5 (79.8–88.5) | 0.264 |
| Heart rate (beats/min) | 81.5 (60.0–101.0) | 77.5 (60.8–104.0) | 81.5 (68.5–101.0) | 0.499 |
Data are presented as median and 25th–75th percentile
PaO2/FiO2 partial arterial oxygen tension on inspired oxygen fraction ratio, PaCO2 partial arterial carbon dioxide tension
avs supine, p < 0.001
bvs recruitment, p < 0.001
cvs supine, p = 0.022
dvs recruitment, p = 0.008
evs supine, p = 0.010
fvs supine, p = 0.013