Objective To analyze the risk factors and prognosis for early acute kidney injury (AKI) after orthotopic liver transplantation (OLT).

Methods The retrospective study was conduc-ted. The clinicopathological data of 340 pairs of donor and recipients undergoing OLT in The First Affiliated Hospital of Nanjing Medical University from January 2016 to January 2020 were collected. There were 262 males and 78 females of donors. There were 268 males and 72 females of recipients, aged (51±11)years. Of 340 recipients, 217 cases without postoperative early AKI were divided into the non-AKI group and 123 cases with postoperative early AKI were divided into the AKI group. Measure-ment data with normal distribution were represented as Mean±SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distri-bution were represented as M(IQR), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi‑square test. Comparison of ordinal data was conducted using the non-parameter test. Multivariate analysis was conducted using the binary Logistic regre-ssion model with forward method. The nomogram predictive model was constructed using the R software with its RMS package (R3.6.1). The efficacy of the predictive model was validated using the area under curve (AUC) of the receiver operating characteristic (ROC) curve, and internal validation of the predictive model was performed using the Bootstrap method. The Kaplan-Meier method was used to draw survival curves, and Log‑rank test was used for survival analysis.

Results (1) Com-parison of preoperative clinical characteristics between donors and recipients of the non‑AKI group and the AKI group. There was a significant difference in overweight of donors between the non‑AKI group and the AKI group (P<0.05). There were significant differences in preoperative hypertension, viral hepatitis, pathological types, international normalized ratio, fibrinogen levels, platelet (PLT), hemoglobin, and anemia of recipients between the non‑AKI group and the AKI group (P<0.05). (2) Comparison of surgical situations between recipients of the non‑AKI group and the AKI group. There were significant differences in intraoperative urine output, volume of intraoperative blood loss, peak serum potassium after reperfusion, massive transfusion, plasma infusion, cryoprecipitate infusion, and aminocaproic acid use of recipients between the non‑AKI group and the AKI group (P<0.05). (3) Influencing factors for postoperative early AKI and construction and evaluation of the nomogram predictive model for postoperative early AKI. Results of multivariate analysis showed that donors of overweight, recipients of preoperative hypertension, recipients of non‑viral hepatitis, recipients of preoperative severe PLT reduction, recipients of less intraoperative urine output, recipients of severe post‑reperfusion hypotension, recipients of high peak serum potassium after reperfusion, recipients with intraoperative plasma infusion were independent risk factors for postoperative early AKI (odds ratio=1.982, 3.365, 0.519, 3.615, 0.169, 2.480, 1.500, 1.001, 95% confidence interval as 1.160-3.388, 1.649-6.865, 0.293-0.917, 1.358-9.621, 0.061-0.464, 1.246-4.934, 1.003-2.243, 1.000-1.001, P<0.05). The nomogram predictive model for postoperative early AKI was constructed based on the results of multivariate analysis. Results of ROC curve showed the AUC was 0.769 (95% confidence interval as 0.717-0.820). Results of the calibration curve showed that the predictive results of nomogram predictive model fitted well with the actual situation, with a mean absolute error of 0.016. (4) Comparison of prognosis between recipients of the non‑AKI group and the AKI group. There were significant differences in postopera-tive peak creatinine, peak brain natriuretic peptide, duration of intensive care unit stay, mechanical ventilation time, re‑intubation of recipients between the non‑AKI group and the AKI group (Z=-4.836, -5.652, -5.861, -6.533, χ²=14.676, P<0.05). All 340 recipients were followed up. For recipients of hepatocellular carcinoma, the 6‑month survival rates after surgery were 87.8% and 75.6% of the non‑AKI group and the AKI group, respectively, showing a significant difference between them (χ²=4.010, P<0.05), and the overall survival rates were 46.7% and 56.1% of the non‑AKI group and the AKI group, respectively, showing no significant difference between them (χ²=0.047, P>0.05). For recipients of benign liver disease, the 6‑month survival rates after surgery were 89.8% and 78.0% of the non‑AKI group and the AKI group, respectively, showing a significant difference between them (χ²=6.401, P<0.05), and the overall survival rates were 81.4% and 68.0% of the non‑AKI group and the AKI group, respectively, showing a significant difference between them (χ²=4.452, P<0.05).

Conclusions Donors of overweight, recipients of preoperative hypertension, recipients of non‑viral hepatitis, recipients of preoperative severe PLT reduction, reci-pients of less intraoperative urine output, recipients of severe post‑reperfusion hypotension, recipi-ents of high peak serum potassium after reperfusion, recipients with intraoperative plasma transfu-sion were independent risk factors for postoperative early AKI. Nomogram predictive model has well clinical application value. For recipients of benign liver disease, the 6‑month survival rate after surgery and overall survival rate of recipients in the non‑AKI group are superior to those of the AKI group.