Comparison of postoperative ascites replacement strategies on time to first flatus after living donor liver transplantation: Albumin vs. lactated Ringer's solution

INTRODUCTION: There is insufficient evidence regarding the optimal regimen for ascites replacement after living donor liver transplantation (LT) and its effectiveness. The aim of this study is to evaluate the impact of replacing postoperative ascites after LT with albumin on time to first flatus during recovery with early ambulation and incidence of acute kidney injury (AKI). METHODS: Adult patients who underwent elective living donor LT at Seoul National University Hospital from 2019 to 2021 were randomly assigned to either the albumin group or lactated Ringer's group, based on the ascites replacement regimen. Replacement of postoperative ascites was performed for all patients every 4 h after LT until the patient was transferred to the general ward. Seventy percent of ascites drained during the previous 4 h was replaced over the next 4 h with continuous infusion of fluids with a prescribed regimen according to the assigned group. In the albumin group, 30% of a total of 70% of drained ascites was replaced with 5% albumin solution, and remnant 40% was replaced with lactated Ringer's solution. In the lactated Ringer's group, 70% of drained ascites was replaced with only lactated Ringer's solution. The primary outcome was the time to first flatus from the end of the LT and the secondary outcome was the incidence of AKI for up to postoperative day 7. RESULTS: Among the 157 patients who were screened for eligibility, 72 patients were enrolled. The mean age was 63 ± 8.2 years, and 73.0 % (46/63) were male. Time to first flatus was similar between the two groups (66.7 ± 24.1 h vs. 68.5 ± 25.6 h, p = .778). The albumin group showed a higher glomerular filtration rate and lower incidence of AKI until postoperative day 7, compared to the lactated Ringer's group. CONCLUSIONS: Using lactated Ringer's solution alone for replacement of ascites after living donor LT did not reduce the time to first flatus and was associated with an increased risk of AKI. Further research on the optimal ascites replacement regimen and the target serum albumin level which should be corrected after LT is required.