2 Variables reflecting dynamic hyperinflation, and oesophageal and gastric pressures and their changes
| Pre-prone semirecumbent | Prone | Post-prone semirecumbent | |
| ΔFRC L# | 0.34±0.13 | 0.31±0.15 | 0.27±0.12 |
| PEEPtot,RS cmH2O# | 11.3±1.5 | 10.4±1.7 | 10.1±1.5 |
| PEEPtot,cw cmH2O# | 2.8±0.4 | 3.3±0.7 | 2.6±0.4 |
| Poes at Vr cmH2O | 12.6±3.1 | 8.6±3.6 | 12.4±3.0 |
| Pga at Vr cmH2O | 9.6±3.7 | 12.9±3.9 | 10.1±3.5 |
| ΔPmax,ga at 0.6 L VT cmH2O# | 3.7±1.1 | 4.2±1.3 | 3.9±1.1 |
| ΔPmax,ga at 1.0 L VT cmH2O | 5.6±1.9 | 6.0±2.4 | 5.9±2.0 |
| ΔP2,ga at 0.6 L VT cmH2O# | 3.3±0.9 | 3.9±1.1 | 3.6±1.0 |
| ΔP2,ga at 1.0 L VT cmH2O | 5.3±1.5 | 5.7±1.9 | 5.5±1.6 |
| Mean maximal amplitude in Poes cmH2O¶ | 2.0±1.2 | 1.7±1.0 | 2.1±1.3 |
| Mean rise rate in Poes cmH2O·s−1¶ | 12.5±5.2 | 11.4±4.7 | 12.8±5.3 |
Data are presented as mean±sd. ΔFRC: change in functional residual capacity; PEEPtot: total positive end-expiratory pressure; RS: respiratory system; cw: chest wall; Poes: oesophageal pressure; Vr: respiratory system relaxation volume; Pga: gastric pressure; ΔPmax,ga: difference between maximal Pga and Pga at Vr; VT: tidal volume; ΔP2,ga: difference between plateau Pga and Pga at Vr. #: values correspond to baseline ventilation conditions; ¶: for each study posture, reported values are mean±sd of determined values during all sets of test breaths (see also fig. 1⇑).