Comparison of Hemodynamic Effects of Two Colloid Therapies in Post-operative Patients Undergoing Pancreaticoduodenectomy

Inclusion Criteria: * Subjects should be meet inclusion criteria to participated into the study 1. Age-from 18-75 years adult 2. In the immediate post-operative period of pancreaticoduodenectomy 3. Written informed consent and admitted ICU immediate post-operative patient Exclusion Criteria: * Any patient meeting one or more of the following exclusion criteria may not be entered into the study. 1. Refusal to participate in the study 2. Evidence of pre-operative oliguria (Serum creatinine\>1.5mmol/dL) 3. Known Severe congestive heart failure (NYHAIII,IV) 4. Known severe respiratory diseases (PaO2/FiO2 \<200) 5. Known coagulopathy (Platelet\<100k/mm3, aPTT\>70s, PT(INR)\>2.5) 6. Known allergy to hydroxyethyl starch 7. Known pregnancy or lactation 8. Has participated in any other clinical trial within 3months 9. Any contraindication to Voluven® or albumin according to their package inserts.