The purpose of this randomized controlled trial in patients undergoing cardiac surgery is to show that a 3rd generation HES (Hydroxyethyl Starch) solution - Tetraspan® is as good as in terms of safety and effectiveness as the commonly used albumin based solution for volume replacement after the surgery.

Inclusion Criteria:

• Written informed consent must be obtained from the subject or his/her legal guardian before any assessment is performed.
• Male or Female subject, 18 years or older.
• Any elective cardiac surgery

Exclusion Criteria:

• Subjects with impaired liver function defined as an elevated level of ALT and AST over 100 U/L.
• Hyperhydration states (e.g. pulmonary edema, congestive heart failure).
• Renal failure with creatinine blood levels > 2.5 mg/dL or eGFR < 30 ml/min (calculated using the DMRD formula).
• Oliguria (UO<0.5ml\kg\hr) or anuria (not related to hypovolemia) more than 12 hours.
• Current Intracranial hemorrhage.
• Current, hard to balance hyperkalemia.
• Severe hypernatremia or severe hyperchloremia.
• Known hypersensitivity to hydroxyethyl starch or to any of the excipients.