| 
      Data expressed in mean ± standard deviation; TO = before fluid therapy; T1 = after
        |  | T0 | T1 | p |  
        | PaO2 (mmHg) | 200± 80 | 220 ± 85 | 0.311 |  
        | PaCO2 (mmHg) | 34.1 ± 3.6 | 34.5 ± 4.1 | 0.819 |  
        | PcvO2 (mmHg) ScvO2 (%) | 30.1 ± 4.8
            53 ± 8 | 31.5 ± 5.0
            58 ± 9 | 0.10
            0.01 |  
        | PcvCO2 (mmHg) | 46.8 ± 4.4 | 44.6 ± 5.3 | 0.03 |  
        | CVA-CO2 tension gradient (mmHg) | 12.6 ± 3.0 | 10.2 ± 3.7 | 0.01 |  fluid therapy. CVA-CO2 tension = central venous-arterial carbon dioxide tension.
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