Incidence rate of postoperative cognitive dysfunction at different anesthetic depths and its correlation with serum levels of RAGE, NR2B, CREB, and NFL

Background Anesthetic depth may affect cognitive function, which is reflected by serum biomarker levels. We aimed to inves­tigate the incidence rate of postoperative cognitive dysfunction (POCD) at different anesthetic depths and its correlations with levels of serum receptor for advanced glycation end product (RAGE), N-methyl-D-aspartate receptor 2B subunit (NR2B), cAMP response element-binding protein (CREB) and neurofilament light chain (NFL). Methods Elderly patients (n=273) undergoing general anesthesia from January 2022 to February 2024 were selected and as­signed to a light anesthesia group [bispectral index (BIS): 60-70, n=98)], a moderate anesthesia group (BIS: 50-60, n=85) and a deep anesthesia group (BIS: 40-50, n=90). The serum levels of RAGE, NR2B, CREB and NFL were detected. Cognitive function was assessed by the Mini-mental State Examination to determine the occurrence of POCD. The correlations of POCD with RAGE, NR2B, CREB and NFL levels were explored by Spearman analysis. Their predictive efficiencies for POCD were evaluated using receiver operating characteristic curves. Results The levels of serum RAGE, NR2B, CREB and NFL had significant differences among groups, at each time point and at each interaction ( p <0.05). At 7 d postoperatively, the CREB level rebounded in all groups, but it was still significantly lower in the deep anesthesia group than in the moderate and light anesthesia groups ( p <0.05). The levels of serum RAGE, NR2B and NFL were posi­tively correlated with the incidence rate of POCD ( p <0.05), but the CREB level was negatively correlated with the rate ( p <0.05). The areas under the curves (AUCs) of serum RAGE, NR2B, CREB and NFL for independently predicting POCD were 0.684, 0.807, 0.725 and 0.718, respectively ( p <0.05), AUC of combination of the four biomarkers was 0.853 ( p <0.05). Conclusions The levels of serum RAGE, NR2B, CREB and NFL are closely correlated with the incidence rate of POCD.