Clinical Study Of Correlation Between Plasma S100β、NFL And α-syn And Postoperative Cognitive Dysfunction In Elderly Patients Undergoing Gastrointestinal Tumor Surgery

Objective:To evaluate the correlation between plasma levels of S100β,neurofilament light chain（NFL）andα-synuclein（α-syn）and postoperative cognitive dysfunction（POCD）in elderly patients undergoing gastrointestinal tumor surgery,and to analyze the incidence and risk factors of POCD.Methods:112 patients aged 65 and over who underwent elective surgery for gastrointestinal tumors were initially enrolled for this study,and finally 84 patients were completed.The cognitive function of all patients was evaluated 1 day before operation and 7 days after operation.The items included Mini mental state examination（MMSE）and Montreal Cognition scale（Mo CA）.One standard deviation method was used to judge the occurrence of POCD.The patients were divided into cognitive impairment group（POCD group）and cognitive normal group（NPOCD group）according to the results of postoperative cognitive function test.Central venous blood 3m L was collected before operation（T₀）,24 hours（T₁）and 72 hours（T₂）after operation,and the contents of S100β,NFL andα-syn in plasma were determined by enzyme linked immunosorbent assay（ELISA）.The differences of three blood biomarkers between POCD group and NPOCD group were analyzed,and the correlation between S100β,NFL andα-syn and POCD and its value in predicting POCD was evaluated.The general baseline data of the patients were collected,the intraoperative anesthetic dosage,bleeding volume,infusion volume and operation duration were recorded,and the postoperative adverse events and complications were recorded to screen out the risk factors of POCD in elderly patients undergoing gastrointestinal tumor surgery.Results:A total of 84 of 112 patients completed 2 cognitive function tests and 3 blood samples collected in this study.1.A total of 22 elderly patients with gastrointestinal tumors developed POCD on the 7th day after operation,with an incidence of 26.19%.2.Univariate analysis showed that age and blood loss were significantly different between the POCD group and the NPOCD group（P<0.05）,and binary logistic regression shown that the risk factor of early POCD in elderly patients undergoing gastrointestinal tumor surgery was age（OR=1.271,95%CI 1.063～1.518,P<0.05）.3.The level of plasma S100β、NFL andα-syn in POCD group and NPOCD group at T₁and T₂ were significantly higher than those at T₀,and the three plasma biomarkers reached the peak level at T₁.4.The plasma levels of S100βand NFL at T₁time point were positively correlated with the decrease of Mo CA score in elderly patients with gastrointestinal tumor（P<0.05）,but there was no significant correlation between plasmaα-syn level and the decrease of MMSE score and Mo CA score at three times point（P>0.05）.5.The area under the curve（AUC）of plasma S100βat T₁ time point for predicting the occurrence of POCD in elderly patients undergoing gastrointestinal surgery was 0.71（95%CI 0.578 to 0.841,P<0.05）,the sensitivity was 59.1%,and the specificity was 79%.The level of plasma NFL at T₁ time point was used to predict the occurrence of POCD with an AUC of 0.718（95%CI 0.595-0.840,P<0.05）,a sensitivity of 81.8%,and the specificity of 54.8%.Both S100βand NFL have the value of predicting POCD,and the accuracy is moderate（AUC>0.7）The value of the combination of S100βand NFL was higher,the AUC was 0.792（95%CI 0.675 to0.909,P<0.05）,the sensitivity is 77.3%,and the specificity is 79%.The level of plasmaα-syn at T₁ time point has no significant value in predicting the occurrence of POCD.The AUC was 0.559（95%CI 0.408-0.709,P>0.05）,the sensitivity was27.3%,and the specificity was 91.9%.Conclusion:1.In this study,the incidence of POCD in elderly patients undergoing gastrointestinal tumor surgery was 26.19%within 7 days after operation,and age was a risk factor for POCD.2.The levels of plasma S100βand NFL 24 hours after operation in elderly patients with gastrointestinal tumors were related to the changes of postoperative cognitive function.S100βand NFL could be used to predict the occurrence of POCD.The combination of S100βand NFL could be used to predict POCD more accurately,whileα-syn could not be used to predict POCD.