Medium and Long Chain Fat Emulsion(C6-24)

Primary objective: To confirm that the effect of SmofKabiven infusion emulsion (study drug) on serum prealbumin levels is non-inferior to the "all-in-one" parenteral nutrition mixture prepared in the hospital (control drug). Secondary objectives: To evaluate the incidence of new postoperative nosocomial infection, prealbumin (day 4), CRP, free fatty acids, TXB3/TXB2, IL-1, IL-2, IL-6, CD4/CD8, taurine levels and safety of SmofKabiven infusion emulsion compared with the "all-in-one" parenteral nutrition mixture prepared in the hospital.