Safety and Efficacy of Perioperative Volume Replacement with Volulyte 6% in Moderate-to-high Cardiovascular Risk Patients Having Major Abdominal Surgery

Individualized goal-directed administration of 6% Hydroxyethyl starch (HES) 130/0.4: After the induction of anesthesia, 200 ml trial fluid will be infused over 20 min. If stroke volume (SV) increases \>10%, another 200 ml fluid will be given. After that, the use of trial fluid will be determined by the patients' Stroke Volume Variation (SVV). If the SVV exceeds 12%, 200 ml trial fluid will be given over 20 min; this will be repeated until SVV \<12%. If the use of HES exceeds 30 ml/kg, sodium acetate Ringer will be replaced. In addition, patients will have a background infusion of sodium acetate Ringer's solution at 4 ml/kg/h to satisfy the maintenance fluid requirements during surgery.

"Individualized goal-directed administration of crystalloid alone: After the induction of anesthesia, 200 ml trial fluid will be infused over 20 min.~If stroke volume (SV) increases \>10%, another 200 ml fluid will be given. After that, the use of trial fluid will be determined by the patients' Stroke Volume Variation (SVV). If the SVV exceeds 12%, 200 ml trial fluid will be given over 20 min; this will be repeated until SVV \<12%. In addition, patients will have a background infusion of sodium acetate, the maintenance fluid requirement during surgery."