Fig. 1

a Plasma neutrophil gelatinase associated lipocalin (NGAL) concentrations preoperatively, at 4 h and at 24 h after surgery presented as box and whisker plots with median, lower and upper quartiles, minimum and maximum. b Urine neutrophil gelatinase associated lipocalin/creatinine (U-NGAL/crea) concentration ratios preoperatively, at 4 h and at 24 h after surgery presented as box and whisker plots with median, lower and upper quartiles, minimum and maximum. c Urine kidney injury molecule-1/creatinine (U-KIM-1/crea) concentration ratios preoperatively, at 4 h and at 24 h after surgery presented as box and whisker plots with median, lower and upper quartiles, minimum and maximum. d Urine interleukin − 18 concentrations preoperatively, at 4 h and at 24 h after surgery presented as presented as box and whisker plots with median, lower and upper quartiles, minimum and maximum