Table 2 Gas exchanges and respiratory mechanics
CMVpre | HFO + 5 | HFO + 10 | HFO + 15 | CMVpost | p value time | |
|---|---|---|---|---|---|---|
mPaw (cm of H2O) | 18 ± 4a,b,c | 23 ± 4b,c,d,e | 28 ± 4a,c,d,e | 33 ± 4a,b,d,e | 17 ± 4a,b,c | <0.001 |
PaO2/inspired O2 fraction (mmHg) | 131 ± 51 | 132 ± 56 | 125 ± 23 | 138 ± 49 | 139 ± 34 | 0.9 |
Inspired O2 fraction | 74 ± 17 | 71 ± 16 | 72 ± 16 | 77 ± 18 | 67 ± 10d | 0.03 |
Arterial pH | 7.29 ± 0.04 | 7.31 ± 0.09 | 7.31 ± 0.01 | 7.29 ± 0.1 | 7.32 ± 0.06 | 0.3 |
PaCO2 (mmHg) | 46 ± 7 | 47 ± 12 | 46 ± 14 | 46 ± 9 | 42 ± 7 | 0.5 |
PEEP (cm of H2O) | 13 ± 3 | NA | NA | NA | 12 ± 3 | 0.4 |
V t (ml/kg) | 6.6 ± 0.7 | NA | NA | NA | 6.7 ± 0.8 | 0.2 |
Plateau airway pressure (cm of H2O) | 24.5 ± 4 | NA | NA | NA | 23.5 ± 4 | 0.06 |
Driving pressure (cm of H2O) | 11.8 ± 3.4 | NA | NA | NA | 11.5 ± 3.3 | 0.4 |
Power of oscillations, % | NA | 73 ± 23 | 79 ± 29 | 81 ± 24 | NA | 0.1 |
Respiratory rate (cycle/min) | 26 ± 4 | NA | NA | NA | 25 ± 6 | 1 |
Oscillatory frequency (Hz) | NA | 4.8 ± 1 | 4.7 ± 0.7 | 4.6 ± 1 | NA | 0.2 |
Inspiratory esophageal pressure | 15 [11.5; 21.2] | NA | NA | NA | 14 [10.2; 17.2] | 0.1 |
Expiratory esophageal pressure | 12.5 [5.1; 13.5] | NA | NA | NA | 9.1 [5.4; 13.5] | 0.1 |
Mean esophageal pressure (cm of H2O) | NA | 12.4 [10.6; 16.7]b,c | 16.7 [12.5; 18.7]a,c | 19.1 [16.7; 23.3]a,b | NA | 0.001 |
Inspiratory P L (cm of H2O) | 8.1 [5.7; 12.8] | NA | NA | NA | 11.8 [5; 12.1] | 1 |
Expiratory P L (cm of H2O) | −1 [−3; + 0.7) | NA | NA | NA | +3.5 [−3; + 6] | 0.2 |
Mean P L (cm of H2O) | NA | 10.5 [7.3; 13.8]c | 13.1 [9.2; 14.7] | 14 [11.5; 16.3]a | NA | 0.001 |
Respiratory system elastance (cm of H2O/L) | 31.2 ± 9.7 | NA | NA | NA | 29.9 ± 8 | 0.2 |
Chest wall elastance (cm of H2O/L) | 15.7 ± 6 | NA | NA | NA | 11.1 ± 4.5 | 0.3 |
Pulmonary elastance (cm of H2O/L) | 15.9. ± 11 | NA | NA | NA | 18.9 ± 6 | 0.3 |