Table 1.
Baseline measurements in the rats before randomization (n = 20)
| Variable | LTV | LTV + LPS | HTV | HTV + LPS | P-value |
|---|---|---|---|---|---|
| Respiration | |||||
| pH | 7.31 ± 0.02 | 7.31 ± 0.03 | 7.30 ± 0.02 | 7.32 ± 0.05 | 0.66 |
| PaCO2 (torr) | 40.3 ± 4.3 | 42.5 ± 4.1 | 42.6 ± 3.6 | 40.7 ± 3.1 | 0.68 |
| PaO2/FiO2 (torr) | 564 ± 60 | 538 ± 45 | 510 ± 31 | 525 ± 49 | 0.36 |
| Pmean (cmH2O) | 7.6 ± 0.5 | 7.8 ± 0.4 | 7.4 ± 0.5 | 7.8 ± 0.8 | 0.70 |
| Hemodynamics | |||||
| MAP (mmHg) | 100 ± 12 | 122 ± 23 | 105 ± 16 | 115 ± 23 | 0.28 |
| CVP (mmHg) | 1.4 ± 0.8 | 2.9 ± 0.9a | 1.5 ± 1.2 | 1.3 ± 0.4 | 0.045 |
| HR (beats/min) | 343 ± 35 | 407 ± 46 | 360 ± 26 | 378 ± 49 | 0.12 |
| LV parameters | |||||
| ESP (mmHg) | 151 ± 16 | 157 ± 16 | 189 ± 36 | 174 ± 30 | 0.13 |
| EDP (mmHg) | 21 ± 9 | 16 ± 13 | 21 ± 5 | 18 ± 8 | 0.78 |
| dP/dtmax (mmHg/s) | 8043 ± 1689 | 8928 ± 2729 | 9912 ± 2709 | 8809 ± 2150 | 0.63 |
| dP/dtmin (mmHg/s) | −10080 ± 1609 | −11917 ± 2954 | −9741 ± 2230 | −11716 ± 2221 | 0.35 |
| Ees/Ea | 1.74 ± 0.64 | 2.03 ± 0.56 | 1.88 ± 0.89 | 1.74 ± 0.80 | 0.91 |
LTV low tidal volume ventilation, LPS lipopolysaccharide, HTV high tidal volume ventilation, CVP central venous pressure, dP/dtmax maximum rate of pressure development, dP/dtmin maximum rate of pressure decline, EDP end-diastolic pressure, ESP end-systolic pressure, Ees/Ea end-systolic elastance/effective arterial elastance ratio, HR heart rate, MAP mean arterial pressure, PaCO2 arterial partial pressure of carbon dioxide, PaO2/FiO2 arterial partial pressure of oxygen/fraction of inspired oxygen ratio, Pmean mean airway pressure
aCVP was higher in the LTV + LPS group compared to the other groups. Data are mean values ± SD