Fig. 3

Screening of differentially expressed metabolites as potential mortality predictors for ARDS. a The differentially expressed metabolites in both the comparison groups, the pink circle representing the group of ARDS vs healthy controls, and the blue circle representing the group of survivors vs non-survivors. The metabolites in the cross area were those identified in both comparison groups. b The box whisker plot of Phenylalanine in the survivors (n = 28) and the non-survivors (n = 15) of ARDS and healthy controls (n = 42). c The box whisker plot of D-Phenylalanine in the survivors (n = 28) and the non-survivors (n = 15) of ARDS and healthy controls (n = 42). d The box whisker plot of phenylacetylglutamine in the survivors (n = 28) and the non-survivors (n = 15) of ARDS and healthy controls (n = 42). e ROC curve of Phenylalanine (AUC = 0.803), D-Phenylalanine (AUC = 0.785) and phenylacetylglutamine (AUC = 0.709) in predicting the mortality of ARDS. In the combined model the area under the curve (AUC) was 0.882. The data was normalized. 1-Lino = 1-Linoleoylglycerophosphocholine; 1,2,3,4-Tera = 1,2,3,4-Tetrahydro-beta-carboline-1,3-dicarboxylic acid; 2-Amino = 2-Aminoacetophenone