Development of a prediction index for persistent acute kidney injury following orthotopic liver transplant

INTRODUCTION AND OBJECTIVES: Acute kidney injury (AKI) is a common complication of orthotopic liver transplantation (OLT). This study aimed to identify factors associated with persistent AKI (pAKI) and to develop a risk index. The impact of pAKI on mortality and renal function over a 5-year period was also assessed. MATERIALS AND METHODS: In this retrospective cohort study, adult OLT recipients were included. pAKI was defined as AKI lasting >72 hours. Logistic regression identified pAKI-associated factors, which were used to create a risk index. Long-term renal function was then evaluated. RESULTS: Among 305 patients, 23 % developed pAKI. The median MELD (Model for End-stage Liver Disease) score was 17. Multivariate analysis identified male sex, reoperation, transfusion of >6 units of red blood cells, anhepatic time >50 minutes, and norepinephrine use >0.25 mcg/kg/min as significant risk factors. The risk index assigned 3 points each to male sex and norepinephrine use, and 5 points to the remaining factors. A score ≥11 had moderate performance (AUC 0.70) and a negative predictive value of 90 %. Patients with pAKI had longer ICU and hospital stays and higher in-hospital mortality. At 5 years, overall mortality did not differ significantly, but those with pAKI had a 10 ml/min/1.73m² lower eGFR. CONCLUSIONS: pAKI is a frequent OLT complication, negatively affecting short-term outcomes and long-term renal function. The proposed risk index effectively identifies patients at low risk, supporting targeted monitoring and prevention.