Acute Kidney Injury After Orthotopic Liver Transplantation: Risk Factors And Prediction Model

Objective:Acute kidney injury is a common postoperative complication of orthotopic liver transplantation,with reported incidence of about 40.8%.Acute kidney injury after orthotopic liver transplantation was associated with immediate complications including volume overload,metabolic acidosis,and electrolyte disturbances and an increased rate of inferior long-term outcomes such as mortality,graft loss,infection,chronic kidney disease,prolonged stay in the intensive care unit,and augmented hospital costs.We aim to explore the risk factors of acute kidney injury after orthotopic liver transplantation and establish a nomogram to predict the episode of acute kidney injury after orthotopic liver transplantation individually.Methods:The clinical data of patients who underwentorthotopic liver transplantation were retrospectively analyzed.The primary outcome was the development of acute kidney injury as defined by Kidney Disease,Improving Global Outcome(KIDGO)staging system.Logistic regression methods were used to detect the risk factors of acute kidney injury after orthotopic liver transplantation,and then to establish the nomogram to individually predict the incidence of acute kidney injury after orthotopic liver transplantation.A nomogram was formulated by using the package of rms in R version3.6.3.The discriminative ability and calibration of the nomogram to predict LT-SSD were tested using area under curve and calibration plots.Data analysis was conducted from September to October 2019,revision in April 2020.Results:According to the episode of AKI(yes/no),patients were classified into AKI group(n=163)and non AKI group(n=81).Compared with patients without AKI,patients with AKI had higher proportion of female gender,higher BMI,higher MELD score,higher intraoperative blood loss,higher intraoperative RBC transfusion and lower preoperative serum creatinine(P<0.05).Multivariate Logistic regression analysis showed that female gender(OR=4.707;95%CI=1.595-13.888;p=0.005),body mass index(OR=1.209;95%CI=1.098-1.332;p<0.0001),MELD score(OR=1.043;95%CI=1.004-1.084;p=0.031),preoperative GFR(OR=1.006;95%CI=1.001-1.011;p=0.012),preoperative serum creatinine(OR=0.982;95%CI=0.971-0.994;p=0.002),intraoperative RBC transfusion(OR=1.040;95%CI=1.001-1.081;p=0.043),anhepatic time(OR=0.975;95%CI=0.957-0.994;p=0.009)were independent risk factors for acute kidney injury after orthotopic liver transplantation.Hosmer-Lemeshow test showed that the goodness of fit of the prediction model was agreeable(X~2=3.62;P=0.89).Receiver operating characteristic curve showed that the area under the curve predicted by prediction model for AKI after orthotopic liver transplantation was 0.77(95%CI:0.71-0.83).Conclusion:Female gender,body mass index,MELD score,preoperative glomerular filtration rate,preoperative serum creatinine,intraoperative RBC transfusion,anhepatic time were independent risk factors for acute kidney injury after orthotopic liver transplantation.Based on the perioperative risk factors for AKI after orthotopic liver transplantation,a nomogram model for predicting the incidence of AKI after orthotopic liver transplantation is established,which has a good calibration and discrimination,and can help clinicians with risk stratification and early recognition,thus enable effective intervention to improve outcomes.