Postoperative Delirium Development Associated with Metabolic Alterations Following Hemi-Arthroplasty in Elderly

Abstract

Background: Postoperative delirium (POD) is a common and harmful complication following surgery in elderly and possible link between metabolic changes during perioperative period and POD development is yet to be investigated. Methods: A nested case-control study was performed through metabolomics to find out the metabolic abnormalities between patients with and without POD. Elderly patients with hip fracture who had hemi-arthroplasty were recruited and their delirious states were assessed for three days after surgery. Simultaneously, fasting blood samples were collected on the morning of surgery and on the first postoperative day. Ultimately, 244 elderly patients who met the inclusion and exclusion criteria completed our observations. The blood samples from 60 patients with POD and 60 matched controls were analyzed using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Findings: Sixty patients (24.6%) developed POD. Eighteen metabolites differed between the 2 groups before surgery, and twenty-three metabolites differed between the 2 groups after surgery. Similarly, thirty metabolites in POD group differed before and after surgery, and thirty-two metabolites in NPOD (Non-POD) group differed before and after surgery. After retrieved KEGG database, our data indicated that, in POD group, ω3 and ω6 fatty acids were lower than NPOD group at both before and after surgery, intermediates of tricarboxylic cycle were lower than NPOD group but products of glycolysis were higher than NPOD group after surgery, branched-chain amino acids (BCAAs) / aromatic amino acids (AAAs) ratio was lower than NPOD group after surgery. Interpretation: The metabolic abnormalities, including deficiencies of ω3 and ω6 fatty acids, abnormal oxygen metabolism, metabolic imbalances in aromatic and branched-chain amino acids, may potentially diminish the brain's inherent protective capacity and hence could contribute to the POD development. Funding Statement: This work was supported by grants from the Shanghai Municipal Commission of Health and Family Planning Foundation for Key Developing Disciplines (2015ZB0103) and the Shanghai Jiao Tong University Biomedical Engineering Cross Research Foundation (YG2015MS15). Declaration of Interests: The authors report no conflicts of interest. Ethics Approval Statement: The study was approved by the Ethics Committee of Shanghai Sixth People’s Hospital affiliated with Shanghai Jiao Tong University (Shanghai, China) and was registered (ChiCTR-CPC-15006141). Written informed consent was obtained from all the participants prior to the study.