Relationship between preoperative serum bilirubin concentration and postoperative delirium in patients undergoing knee or hip replacement / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between preoperative serum bilirubin concentrations and postoperative delirium (POD) in the patients undergoing knee or hip replacement.Methods:Medical records from 413 patients undergoing knee or hip arthroplasty were selected from August 2020 to October 2023 at Qingdao Municipal Hospital using a nested case-control design based on the PNDABLE study cohort. The patients were divided into POD group ( n=77) and non-POD group ( n=336) according to whether POD occurred. Univariate analysis was used to analyze the influencing factors. Logistic regression was used to identify the risk factors for POD. The significance of mediation effect was tested. The receiver operating characteristic curve was drawn to evaluate the accuracy of risk factors in predicting POD. Results:There were significant differences in age, education time, ratio of diabetes history, Memorial Delirium Assessment Scale score, total bilirubin concentration, direct bilirubin concentration, indirect bilirubin concentration, Aβ 42 concentration, p-tau concentration, t-tau concentration, Aβ 42/p-tau ratio and Aβ 42/t-tau ratio between POD group and non-POD group ( P<0.05). The results of logistic regression analysis showed that preoperative serum total bilirubin, direct bilirubin and indirect bilirubin were risk factors for POD ( P<0.05). The results of mediation effects showed that the concentration of total tau protein in CSF partly mediated the relationship between high serum total bilirubin, direct bilirubin and indirect bilirubin concentrations and POD. The area under the receiver operating characteristic curve of total bilirubin, direct bilirubin and indirect bilirubin combined with CSF biomarker concentrations in predicting POD was 0.83 ( P<0.001). Conclusions:Preoperative elevated concentrations of total bilirubin, direct bilirubin and indirect bilirubin are risk factors for POD in the patients undergoing knee or hip replacement. CSF t-tau concentration has a partly mediating role in the association between serum total bilirubin, direct bilirubin and indirect bilirubin concentrations and the development of POD.