RESUMO
Introduction: Post-operative delirium (POD) is a serious complication which occurs after surgery, especially in the elderly undergoing abdominal surgery. Increasing evidence has revealed an association between the gut microbiota and psychological disorders involving the "brain-gut" axis. However, the association between the pathogenesis of POD after abdominal surgery in aging and composition of the gut microbiota remains unclear. Methods: Forty patients (≥65 years old) who underwent abdominal surgery were included in the study. Twenty patients had POD, whereas 20 patients did not. POD was diagnosed and assessed using the confusion assessment method (CAM) during the postoperative period. Total DNA fractions were extracted from all fecal samples of patients. 16S rRNA sequencing was performed to determine the composition of the gut microbiota. The quality of the samples was determined by calculating the α- and ß-diversities. Results: The α- and ß-diversities indicated that the samples were eligible for detection and comparison. We observed multiple differentially abundant bacteria in patients with and without POD. Generally, Proteobacteria, Enterbacteriaceae, Escherichia shigella, Klebsiella, Ruminococcus, Roseburia, Blautia, Holdemanella, Anaerostipes, Burkholderiaceae, Peptococcus, Lactobacillus, and Dorea were abundant in the POD cohort, whereas Streptococcus equinus and Blautia hominis were abundant in the control cohort. The results of receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of Escherichia shigella was 0.75. Phenotype prediction showed that the gut microbiota may influence POD by altering the tolerance to oxidative stress. Conclusion: There were significant associations between the pathogenesis of POD and composition of the gut microbiota. Escherichia shigella are promising diagnostic bacterial species for predicting POD onset after abdominal surgery in elderly people. Clinical Trial Registration: http://www.chictr.org.cn/index.aspx, Chinese Clinical Trial Registry ChiCTR200030131.
RESUMO
Accumulating evidence has demonstrated significant clinical post-traumatic stress disorder (PTSD) symptoms after anesthesia or surgery. Fear extinction dysfunction is a notable feature of PTSD. Although anesthetics and surgery profoundly affect memory processes, their designated effects on fear extinction have not been dissertated. Previous studies have suggested that innate immune system activation disrupts fear extinction, and surgery has been shown to increase the inflammatory response. Thus, in the current study, we examined the effects of propofol, sevoflurane, dexmedetomidine and surgery on fear extinction in adolescent mice, and further tested whether dexmedetomidine could reverse the injury effect of surgery on fear extinction through its anti-inflammatory effects. Our results showed that propofol (200 mg/kg) impaired the acquisition and recall of cued fear extinction, and surgery disrupted cued fear extinction acquisition/recall and consolidation. In contrast to cued fear extinction, contextual fear extinction was not affected by propofol or surgery. Moreover, dexmedetomidine prevented surgery-induced impairment of cued extinction acquisition and recall but not consolidation. Finally, TNF-α and IL-6 levels in the ventromedial prefrontal cortex were not necessary for the dexmedetomidine treatment effect of surgery-induced fear extinction dysfunction. The study results showed that propofol and surgery selective impaired the cued fear extinction stage in adolescent mice, and dexmedetomidine may unleash a protective effect in preventing postoperative PTSD.
