Table 2.
Ventilatory settings used during the studya
| SP | PP | SP | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Ventilatory setting | Time 0 | Time 1 (RM1) time 2 | Time 3 | Time 4 (RM2) time 5 | Time 6 (RM3) time 7 | Time 8 | |||
| Vt, mL | 536 ± 105 | 522 ± 106.8 | 534 ± 102 | 532 ± 102 | 511 ± 99 | 511 ± 98.7 | 512 ± 97.8 | 512 ± 98.2 | 512 ± 98 |
| RR, breaths/minute | 19 ± 4.1 | 19.5 ± 4.1 | 19.5 ± 4.3 | 19.5 ± 4.3 | 20 ± 4.4 | 20 ± 4.4 | 20 ± 4.4 | 20 ± 4.4 | 20 ± 4.4 |
| V°, L/minute | 10.5 ± 2.3 | 10.2 ± 2 | 10.4 ± 2.2 | 10.4 ± 2.1 | 10.2 ± 2.2 | 10.2 ± 2.2 | 10.2 ± 2.2 | 10.3 ± 2.2 | 10.3 ± 2.2 |
| External PEEP, cmH2O | 9.8 ± 2.8 | 9.8 ± 2.8 | 9.8 ± 2.8 | 9.8 ± 2.8 | 10.1 ± 2.6 | 10.1 ± 2.6 | 10.1 ± 2.6 | 10.1 ± 2.6 | 10.3 ± 2.7 |
| Total PEEP, cmH2O | 10.7 ± 2.8 | 10.6 ± 2.8 | 10.8 ± 2.9 | 10.8 ± 2.7 | 10.9 ± 3 | 11.4 ± 3.3 | 10.5 ± 2.8 | 10.6 ± 2.9 | 10.8 ± 3 |
| Paw, cmH2O | 31.7 ± 4.7 | 30.5 ± 6 | 30.2 ± 5.7 | 31 ± 4.9 | 29 ± 5.2 | 30.5 ± 5.2 | 29 ± 5.9 | 28 ± 5.3 | 29 ± 5.3 |
| Pplat, cmH2O | 24.6 ± 5.8 | 24.5 ± 5.7 | 24 ± 5.5 | 25.3 ± 5b | 24.2 ± 4.6 | 24 ± 4.1 | 23.4 ± 4.9 | 22.7 ± 5c | 23 ± 5.1 |
aPaw: peak airway pressure; Pplat: plateau pressure; Vt: tidal volume; RR: respiratory rate; V°: minute volume; PEEP: positive end expiratory pressure; SP: supine position; PP: prone position; RM recruitment maneuver. Ventilatory settings were measured each time (from time 0 to time 8) in SP and PP (see Figure 2): inclusion, before and after each RM, before PP, and at the end of the protocol (1 hour after turning to the SP). bTime 3 versus time 2: P = 0.035; ctime 6 versus time 7: P = 0.02. All data are expressed as means ± standard deviations.