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Table 2 Gas exchanges and respiratory mechanics

From: Effect of high-frequency oscillatory ventilation on esophageal and transpulmonary pressures in moderate-to-severe acute respiratory distress syndrome

  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
  1. P L transpulmonary pressure, NA not applicable
  2. p values in italic are provided for < 0.05
  3. ap < .05 vs. HFO + 5, b p < .05 vs. HFO + 10, c p < .05 vs. HFO + 15, d p < .05 vs. CMVpre, e p < .05 vs. CMVpost