| Objective:To investigate the relationship between preoperative subjective cognitive decline and postoperative delirium in patients underwent total hip replacement under spinal epidural anesthesia.Methods:A total of 1471 patients,regardless of sex,age 40～90 years,ASA grade I or II,preoperative Mini Mental State Examination（MMSE）scale score>23,and Montreal Cognitive Assessment（Mo CA）scale score>26,underwent total hip replacement under spinal epidural anesthesia from June 2020 to May 2022 were selected.MMSE and Mo CA scales were used to assess the preoperative cognitive function of patients on the day before operation,Subjective Cognitive Decline Scale（SCDS）was used to evaluate whether they had SCD at the same time,all patients were divided into SCD group or non SCD（NSCD）group according to the assessment results.On the operation day,the patient received spinal epidural anesthesia.After successful puncture,2ml of cerebrospinal fluid（CSF）was extracted and stored properly.Subsequently,the concentrations of CSF of Amyloid protein40(Aβ40)、Aβ42、total tau protein（t-tau）and phosphorylated tau protein（p-tau）were determined by enzyme linked immunosorbent assay（ELISA）.The incidence and severity of POD were evaluated with the Confusion Assessment Method（CAM）and Memory Delirium Assessment Scale（MDAS）during PACU and 1-7 days after operation（or before discharge）from 10 a.m.to 12 p.m.and from 6 p.m.to 8 p.m.every day.Results:1148 patients were finally were involved in the result analysis.The preoperative SCDS evaluation results showed that 409 patients had SCD,the overall proportion of SCD patients was 35.6%（n=409/1148）,and the remaining 739 patients were in a cognitively normal（CN）state.The diagnostic results of CAM scale after surgery showed that the overall incidence of POD was 19.6%（n=225/1148）.120 patients in the SCD group had POD after surgery,and the incidence of POD was 29.3%（n=120/409）,while 105 patients in the Non SCD group had POD,and the incidence of POD was only14.2%（n=105/739）.According to the detection results of biomarkers in CSF samples of two groups of patients before surgery,compared with the Non SCD group,the concentration of Aβ42,the ratios of Aβ40/t-tau、Aβ42/t-tau and Aβ42/p-tau in CSF samples of patients in SCD group were lower,while the concentrations of t-tau and p-tau,the ratios of Aβ40/Aβ42 was higher（p<0.05）.The results of single factor regression analysis to explore the influencing factors of POD showed that preoperative SCD（OR=2.507,95%CI:1.864～3.373,p<0.001）,the increased concentrations of t-tau（OR=1.004,95%CI:1.003～1.005,p<0.001）and p-tau（OR=1.045,95%CI:1.037～1.054,p<0.001）in CSF were the risk factors for POD,while the increased concentration of Aβ42（OR=0.998,95%CI:0.997～0.999,p<0.001）in CSF was the protective factors for POD;Based on univariate regression analysis,after correction of age,whether or not the merger with hypertension,diabetes and coronary heart disease,preoperative MMSE,Mo CA,PSQI score,operation time,anesthesia time,NRS score 24 hours after operation and other confounding factors,the results showed that preoperative SCD（OR=1.467,95%CI:1.015～2.120,p=0.042）and increased concentrations of p-tau（OR=1.046,95%CI:1.028～1.063,p<0.001）in CSF were still risk factors for POD.At the same time,we further included gender,ASA classification,height,weight,drinking history,smoking history,education level,infusion volume,bleeding volume,urine volume and other covariates for sensitivity analysis,which was consistent with the results of multivariate regression analysis[SCD（OR=1.457,95%CI:1.004～2.116,p=0.048）,p-tau（OR=1.044,95%CI:1.027～1.062,p<0.001）].According to the results of regression analysis,specific CSF biomarkers were selected as intermediary variables for intermediary effect analysis.The results showed that the occurrence of POD caused by SCD was partially mediated by p-tau,of which the proportion of intermediary effect was about 31.25%(p-tau,IE=4.279×10-2,p<0.001).Conclusion:Preoperative SCD is a risk factor for POD in patients undergoing total hip arthroplasty,and the increase of p-tau concentration in CSF of SCD patients may predict the occurrence of POD in patients undergoing total hip arthroplasty. |
