Abstract: 【Abstract】Objective To analyze the predictive ability of early urinary biomarkers for the occurrence of acute kidney injury (AKI) in patients with mechanical ventilation. Methods Urine samples were collected from the patients with invasive mechanical ventilation for 24 hours in the ICU of the First Affiliated Hospital, Xi’an Jiaotong University from June to September 2019. The concentrations of liver fatty acid binding protein (L-FABP), tissue inhibitor of metalloproteinasE2 (TIMP-2) and insulin-like growth factor binding protein-7 (IGFBP-7), the three novel biomarkers for AKI, were determined in the urine samples in order to predict the presence of AKI earlier. Results Of the 31 patients with invasive mechanical ventilation, 11 (35.48%) were diagnosed with AKI and 20 (64.52%) without AKI. The rates of older age, higher score of sequential organ failure assessment (SOFA), and more than 3 kinds of underlying diseases were higher in the patients with AKI than those without AKI (t/c2=-5.670, -4.810 and 16.439 respectively, P=0.003, 0.001 and ＜0.001 respectively). Logistic regression showed that invasive mechanical ventilation was the main risk factor for AKI (OR=1.58, 95% CI 1.124～1.739, P=0.009). The risk of AKI increased with the duration of mechanical ventilation. There was no difference in prognosis between the patients with AKI and those without AKI. The product of TIMP-2 and IGFBP-7 predicted closely the presence of AKI; and the receiver operating characteristic (ROC) revealed that the AUC was 0.803 (95% CI 0.627～0.978, P=0.005), the sensitivity was 0.750, and the specificity was 0.895. Conclusion The product of urinary biomarker TIMP-2 and IGFBP-7 can effectively predict the presence of AKI in patients with mechanical ventilation.

Key words: Acute kidney injury, Biomarker, Mechanical ventilation, Ventilator induced kidncy injury