Patients after abdominal surgery will attempt enteral nutrition support for 2 days, if she/he can not tolerate 30% of target energy, then she/he will be randomized to early PN group or late PN group at day 3. Patients in early PN group will receive supplemental parenteral nutrition at day 3 while patients in late PN group will not receive supplemental parenteral nutrition until day 8 after abdominal surgery. Both groups will receive SPN except 80% of target energy delivered by EN or oral or patients are discharged from hospital. The primary and secondary outcomes will be collected.
Patients will be randomized to early PN group or late PN group at day 3 after abdominal surgery. Patients will receive supplemental parenteral nutrition or not within 7 days after abdominal surgery. Both groups will receive SPN except 80% of target energy delivered by EN or oral or patients are discharged from hospital. The primary and secondary outcomes will be collected.