Crystalloids or Colloids for Goal-directed Fluid Therapy With Closed-loop Assistance in Major Surgery

Study goal: This study will examine whether there is a significant difference in postoperative outcomes between GDFT using a colloid solution versus a crystalloid solution. Hypothesis: Perioperative fluid optimization through the use of a closed-loop assistance with a balanced starch solution (volulyte®) will be associated with a decrease in postoperative complications compared to the same approach using a balanced crystalloid solution (Plasmalyte®). Objective: To establish which kind of intravenous fluid used for goal directed therapy with closed-loop assistance will reduce the number of postoperative complications (evaluation made by the POMS score).