Blood pressure is generally maintained at value not less than 80% of baseline during intraoperative period. If the blood pressure is within normal range and SVV is less than 9, patient will be given a continuous infusion of crystalloid solution. However, when blood pressure drops and SVV is greater than 13, a bolus of 200mL colloid will then be quickly administered. If the blood pressure doesn't recover back to normal range within 5 minutes after bolus, norepinephrine will be given through the central venous catheter. If SVV is between 9 and 13, a bolus of crystalloid at 8mL/kg/h will be administered

Blood pressure is generally maintained at value not less than 80% of baseline during intraoperative period. If the blood pressure is within normal range and SVV is less than 9, patient will be given a continuous infusion of crystalloid solution. However, when blood pressure drops and SVV is greater than 13, a bolus of 200mL colloid will then be quickly administered. If the blood pressure doesn't recover back to normal range within 5 minutes after bolus, phenylephrine will be given through the central venous catheter. If SVV is between 9 and 13, a bolus of crystalloid at 8mL/kg/h will be administered.

patient who was received the treatment of norepinephrine

(CO)cardiac output in Litres per minute. the indicator reflect the patients hemodynamic, which measured by the FloTrac/Vigileo 3.0

Blood samples from the radial artery and internal jugular vein were taken at the same time in three time points respectively to measure arterial and venous blood gas, and Measured tissue oxygenation according to Fick equation:DO2(ml/min/m2)=CaO2×10×CI, Arterial oxygen content (CaO2)=Arterial hemoglobin concentration(Hba)×1.36×arterial oxygen saturation(SaO2) + 0.0031×arterial oxygen pressure (PaO2) ;

Blood samples from the radial artery and internal jugular vein were taken at the same time in three time points respectively to measure arterial and venous blood gas, and Measured tissue oxygenation according to Fick equation:VO2(ml/min/m2)= (CaO2-CcvO2)×CI×10, Intravenous oxygen content (CcvO2)= Intravenous hemoglobin concentration (Hbv)×1.36×Venous oxygen saturation (ScvO2) + 0.0031×venous oxygen pressure (PcvO2);