Fig. 4

a ROC curves for AKI based on uL-FABP levels at the end of surgery. The AUC was 0.8030 (95 % CI 0.68–0.94. ROC receiver operating characteristic, AUC area under the curve, uL-FABP urinary L-type fatty acid-binding protein, AKI acute kidney injury. b ROC curves for AKI based on uNGAL levels 3 h after surgery. The AUC was 0.8687 (95 % CI 0.76–0.98). ROC receiver operating characteristic, AUC area under the curve, uNGAL urinary neutrophil gelatinase-associated lipocalin, AKI acute kidney injury