Tetraspan 6 Percent (%) Combined With Sterofundin ISO Versus Albumin 5 Percent (%) Combined With Sodium Chloride (NaCL)

Inclusion: * male or female patients * ≥ 50 years of age; * patients with compromised renal function, i.e. serum creatinine between 1.5 mg/dl and 3.0 mg/dl; * patients scheduled for elective intervention; * patients with an estimated intraoperative volume need of at least 1 l colloids; * provision of voluntary informed consent to participate in the study, following a full explanation of the nature and purpose of the study, by signing the informed consent form approved by the Institutional Ethics Committee (IEC) prior to all evaluations Exclusion: * patients of ASA-class \> III; * patients with daily urine output \< 1 l; * patients on haemodialysis; * patients receiving HES during the last 48 hours before first infusion of the investigational products; * patients suffering from coagulation disorders (i.e. PTT \> 60 sec); * patients with a hemoglobin \< 9 g/dl; * patients with known hypersensitivity to HES, albumin or any of the excipients; * patients suffering from contraindications of the investigational products (i.e. hyperhydration state including pulmonary oedema, renal failure with oliguria or anuria, intracranial haemorrhage, hyperkalaemia, severe hypernatraemia or severe hyperchloraemia, severely impaired hepatic function, congestive heart failure); * simultaneous participation in another clinical trial; emergencies; * patients scheduled for brain surgery; * patients incapable to give informed consent (e.g. patients with dementia, psychiatric diseases or suffering from conditions associated with lack of consciousness)