Effect of Preoperative Oral Carbohydrate Loading on Postoperative Outcomes in Liver Transplant Patients

The aim of the study is to evaluate the effect of preoperative oral carbohydrate loading on postoperative recovery in liver transplant recipients. Additionally, the study aims to assess the effect of preoperative oral carbohydrate loading on additional recovery parameters following liver transplantation, such as length of stay in the intensive care unit, time to first oral intake, and time to recovery of gastrointestinal function.

Participants will be randomly assigned in a 1:1 ratio to the study group or control group using block randomization with a block size of 10. A randomization list of 440 allocations will be generated prior to enrolment. Recruitment will end after the planned sample size of 434 participants is achieved and remaining allocations will not be used. Patients assigned to the study group will receive 400 mL of a carbohydrate beverage (Nutricia preOp®), to be consumed up to 2 hours before the anesthesia induction. Patients assigned to the control group will receive 400 mL of a placebo administered in an identical manner as in the study group. Participants will not be informed which group they have been assigned to.

In the postoperative period, routine laboratory and imaging tests will be performed, and their results will be used to assess the effects of the intervention. Follow-up of the patient's clinical course is planned for up to 30 days after surgery. The schedule of follow-up visits will not differ from standard clinical practice. No biological material will be collected or stored for the purposes of this study.

Hospital-Free Days at 30 (HFD30), defined as the number of days a patient is both alive and discharged from the hospital within the first 30 days after transplantation, will serve as the primary endpoint, reflecting early postoperative recovery. Based on retrospective data, the mean number of HFD30 was 9.4, with a standard deviation (SD) of 7.1. To detect a 2-day difference with 80% power and a two-sided alpha of 0.05, assuming a 10% early postoperative loss, a total of 434 patients (217 per group) will be required.

Inclusion criteria

• age ≥ 18 years
• elective liver transplantation at the Department of General, Transplant, and Liver Surgery, Medical University of Warsaw
• grafts from brain-dead donors
• MELD score <35

Exclusion criteria

• acute liver failure
• insulin-dependent diabetes mellitus
• gastroparesis
• mechanical bowel obstruction
• liver retransplantation within less than 6 months of the primary transplant