To conduct a metabonomics study of blood plasma from intensive care unit (ICU) patients with delirium based on magnetic resonance spectroscopy (NMR).

Thirty-six ICU patients were selected prospectively from February 2016 to September 2017, and divided into either a delirium group or a non-delirium group, with 18 patients in each group. NMR was performed to analyze the difference in serum metabolomics between the two groups. Principal component analysis (PCA) was used for multivariate data analysis, partial least-squares discriminant analysis (PLS-DA) was used for model validation, and orthogonal partial least-squares discriminant analysis (OPLS-DA) was used to screen and identify metabolites with significant differences between the two groups.

Metabonomics analysis indicated that plasma concentrations of valine, leucine, alanine, and acetoacetate in the delirium group were significantly increased compared with the non-delirium group, while plasma concentration of citrate significantly decreased in the delirium group compared with the non-delirium group. Those metabolites were associated with amino acid metabolism, tricarboxylic acid, and ketone body metabolism.

When delirium occurs in ICU patients, the body′s amino acid metabolism, tricarboxylic acid circulation, and ketone body metabolism are abnormal. NMR-based metabolomics technology can help identify different markers of metabolites in delirium patients.