Safety and Efficacy of 6% Hydroxyethyl Starch (HES) Solution Versus an Electrolyte Solution in Patients Undergoing Elective Abdominal Surgery

Inclusion: * Male or female adult patients \> 40 and ≤ 85 years of age. Women of child bearing potential must test negative on standard pregnancy test (urine or serum) * Patients undergoing elective abdominal surgery with an expected blood loss of ≥ 500 ml * ASA Physical Status II - III * Signed written informed consent form Exclusion: * Hypersensitivity to the active substances or to any of the other excipients of the investigational medicinal products * Body weight ≥ 140 kg * Sepsis * Burns * Renal impairment (AKIN stage ≥ 1 or chronic) or acute and/or chronic renal replacement therapy * Intracranial or cerebral haemorrhage * Critically ill patients (typically admitted to the intensive care unit) * Hyperhydration * Pulmonary oedema * Dehydration * Hyperkalaemia * Severe hypernatraemia * Severe hyperchloraemia * Severely impaired hepatic function * Congestive heart failure * Severe coagulopathy * Organ transplant patients * Metabolic alkalosis * Simultaneous participation in another interventional clinical trial (drugs or medical devices studies)