Table 2.
Ventilatory and respiratory variables
| High VT | Low VT PEEP | P-value | |
|---|---|---|---|
| VT (mL) | 755 ± 118 | 390 ± 79 | <0.0001 |
| Ventilatory rate (L/min) | 8 ± 1.4 | 12 ± 3.3 | 0.001 |
| Pawmax (cm H2O) | 23 ± 6 | 19 ± 2.3 | 0.22 |
| Pawmean (cm H2O) | 7 ± 2.5 | 9.1 ± 0.9 | 0.1 |
| ETCO2 (mmHg) | 32 ± 4.5 | 36 ± 5.8 | 0.05 |
| pH | 7.44 ± 0.05 | 7.38 ± 0.05 | 0.005 |
| PaO2 (mmHg) | 199 ± 45 | 233 ± 62 | 0.1 |
| PaCO2 (mmHg) | 35 ± 6 | 43 ± 6 | 0.002 |
Values are presented as means ± SD.
VT=tidal volume, PEEP=positive and-expiratory pressure, Pawmax=maximal airway pressure, Pawmean =mean airway pressure, ETCO2=end-tidal carbon dioxide, PaO2=arterial blood oxygen tension, PaCO2=arterial carbon dioxide tension.
The High VT group received mechanical ventilation with a VT of 12 mL/kg ideal body weight and no PEEP; the Low VT PEEP group received mechanical ventilation with a VT of 6 mL/kg ideal body weight with PEEP of 8 cm H2O