 Patients who are scheduled for: elective oesophageal tumour resection, total gastrectomy, pancreas resection, major vascular, total cystectomy will be recruited.To investigate effects of central venous pressure CVP and central venous saturation ScvO2 guided fluid management on intraoperative haemodynamic parameters, volume and vasopressor requirement, and postoperative organ function and postoperative inflammatory response. 