FREQUENCY AND PREDICTIVE FACTORS OF ACUTE KIDNEY INJURY IN THE POST- LIVER TRANSPLANTATION

Acute Kidney Injury (AKI) is one of the most common complications in the postoperative period of liver transplantation (LT), occurring in approximately 72% of patients(1,2). This clinical condition impacts mortality rates, hospitalization time, financial resources, and increases the risks of infection or potential recipient rejection(3). Various factors influence the clinical outcome of AKI in this scenario. The purpose of this study was to assess the frequency and predictive factors of AKI in postoperative period of LT.

This is an observational, cross-sectional study, involving retrospective data analysis. Data were be collected from medical records at a LT reference hospital in Brazil, for subsequent statistical analysis. Patients transplanted from january 2012 to july 2022 were included, with exclusion criteria comprising whom submitted to dual liver and kidney transplantation, retransplant and those with pre-existing renal disease. 

The study included 223 patients, with 115 (54.5%) developing AKI in the first seven days postoperatively. This group was predominantly male (70.9%), with an average age of 53.46 (SD=±12.8 years) and a mean MELD score of 28.87 (SD=±6.1). The average body mass index (BMI) was 26.26 (SD=±21.5). The main indications for LT were Hepatitis C (29.6%) and Alcoholic Liver Disease (23.8%). Among these patients, 55.2% had hepatocellular carcinoma, 36.4% had hypertension (HTN), 28% had diabetes (DM), and 5.6% had dyslipidemia. In predictive factor analysis, 50% of female patients experienced AKI, compared to 56.3% in males (p=0,408). In univariate analysis were associated with AKI dyslipidemia (83.3% vs. 16,7% in non-AKI; p < 0.04), HCC (47,4% vs 52,6% in non-AKI, p<0,06), HTN (50,6% vs 49,9%,p<0,4) and DM (63,9% vs 36,1%,p<0,08). Concerning blood transfusion, 77.8% of those receiving 3 to 5 units and 75% of those receiving more than 5 units developed AKI (p<0,01). Early complications increased the percentage of patients with the studied clinical outcome to 68.8% (p<0,001). Another variable analyzed was the use of vasopressor drugs, with 60.8% of patients using them developing AKI (p<0,01). In multivariate analysis age (54,19±11,4 vs 53,49±13,7, p<0,7), BMI (1,817±0,8 vs. 1,759±0,9,p<0,7) and MELD (21,67±5,7 vs. 20,06±6,5, p<0,11) were associated with AKI.

Various factors are predictive of post-liver transplantation AKI including pre-existing comorbidities such as HTN, dyslipidemia, DM and high MELD scores. Additionally, perioperative and postoperative factors such as blood transfusion, particularly when employing more than two hemoglobin concentrates, vasopressor drug use, early complications such as infections and sepsis, hemodynamic instability, also play a significant role.