To investigate the applicability of NMF criteria in determining the optimal timing for initiating RRT in patients experiencing AKI following liver transplantation.

A retrospective analysis was conducted on the clinical data of patients with AKI following liver transplantation, who were admitted to ICU at LiHuili Hospital, affiliated of Ningbo University, from January 2018 to June 2023. Based on previous research findings, criteria for NMF were established, and 173 patients were categorized into four distinct groups: (1) Group A (n=41), comprising patients who met the NMF criteria and received renal replacement therapy (RRT) within 6 hours of ICU admission; (2) Group B (n=55), consisting of patients who met the NMF criteria but either did not receive RRT or received RRT after ≥ 6 hours post-ICU admission; (3) Group C (n=18), including patients who did not meet the NMF criteria but received RRT within 6 hours of ICU admission; and (4) Group D (n=59), comprising patients who neither met the NMF criteria nor received RRT, or who received RRT after ≥ 6 hours post-ICU admission. Conduct a comprehensive analysis and comparison of patient demographic and clinical characteristics, including age, gender, BMI, etiology, SOFA score, APACHE Ⅱ score, timing of transplant surgery, surgical technique, and incidence of hepatic coma. Evaluate clinical indicators such as serum creatinine, MELD-Na score, and blood ammonia levels preoperatively, postoperatively, and on the third and seventh days following transplantation. Assess prognostic outcomes by examining cumulative durations of mechanical ventilation, ICU stay, and total hospitalization, as well as 28-day, 90-day, and 1-year mortality rates. Additionally, evaluate the occurrence of CRBSI, CKD, liver dysfunction, and the requirement for long-term RRT. For intergroup comparisons, employ the t-test for normally distributed continuous variables, the Mann-Whitney U test for non-normally distributed continuous variables, and the chi-square test or Fisher′s exact test for categorical variables. A P-value of less than 0.05 will be considered indicative of a statistically significant difference.

Statistically significant differences were observed in serum creatinine and blood ammonia levels between patients in Group A and Group B on the third and seventh days following surgery, as well as in MELD-Na scores on postoperative day 7 (U/t= 2.245.30, 7.37, 7.55, 2.73, all P<0.05). Significant differences in serum creatinine and blood ammonia levels were noted between patients in Group C and Group D on the third day post-surgery (U=2.21 and 5.20, both P<0.05). Furthermore, significant differences were identified in the total length of hospital stay and the incidence of tracheostomy, concurrent CKD and long-term RRT between Group A and Group B (t/χ²=3.23, 4.59, 3.93, all P<0.05). Additionally, a statistically significant difference was found in the incidence of CRBSI between Group C and Group D (P<0.05).

According to the NMF criteria, patients with AKI who receive RRT following liver transplantation demonstrate significant improvements in postoperative serum creatinine levels, MELD-Na scores, and blood ammonia levels. Additionally, these patients experience a reduced total hospital stay, a lower incidence of CKD complications, and a decreased necessity for long-term RRT. Conversely, patients who do not meet the NMF criteria yet undergo RRT exhibit a heightened incidence of CRBSI.