The Relationship Between Postoperative Cognitive Dysfunction And Cerebral Oxygen Saturation:a Meta Analysis

ObjectivePostoperative cognitive dysfunction(POCD)is a common postoperative complication of a series of changes in behavioral and neurocognitive status in patients weeks or even months after surgery.The occurrence of POCD puts the patient at risk of losing his or her job and independent life,and the quality of life is also significantly reduced.A number of studies have demonstrated the relationship between POCD and intraoperative cerebral oxygen saturation(rSO2).While the quality of research varies,and the findings are mixed and confusing.Therefore,it is necessary to carry out a meta-analysis of the current research results,to study the relationship between POCD and intraoperative cerebral oxygen saturation changes,and to analyze the significance of intraoperative cerebral oxygen saturation monitoring for clinical prevention and treatment of POCD.MethodsA total of four commonly used English databases were searched by computer,including Embase,Web of Science,Pubmed(Medline)and Cochrane Library.The search time was up to February 6,2018.The search requirement was to search as many relevant documents as possible and to search relevant documents in the literature in addition to those retrieved from the database.The inclusion criteria for this study were:(1)The study subject must be adults(2)The test group and the control component group should be clear(3)The test group diagnosis method should be explained(4)The experimental data outcomes can use a binary or continuous variable,but it needs to be able to provide enough data for data analysis.Literature exclusion criteria:(1)Non-english literature(2)literatures that can not provide specific data such as review,letter,case reports,s,etc.(3)Literature data is incomplete,literature data is repeated(4)Document design has serious defects no control group experiment was established and the diagnostic criteria of the experimental group were not clearly defined.Newcastle-Ottawa Scale was used to evaluate the quality of all documents.The RevMan5.2 software was used to calculate the standardized mean difference(SMD)and its 95%confidence interval to evaluate the relationship between postoperative cognitive dysfunction and intraoperative cerebral oxygen saturation changes.Sensitivity analysis and subgroup analysis were used to determine the difference between studies.ResultsA total of 267 articles were retrieved in the four databases.A total of 594 patients in 7 literatures were included in this meta analysis.Heterogeneity test outcome is 12-55%calculated by software,suggesting heterogeneity exsists,using a random effects model to calculate the total effect.The SMD is-0.55,95%CI:[-0.86,-0.25],P=0.0004,suggesting that the average value of intraoperative cerebral oxygen saturation in patients with POCD was less than those without POCD,and the results were statistically significant.Sensitivity analysis was used to determine the source of heterogeneity.In the sensitivity analysis,following the study of Seong Wook Hong,heterogeneity test outcome is I2 28%<50%,means the heterogeneity was significantly reduced.In this study,subgroup analyses were performed according to age and type of surgery.Only Seong Wook Hong's study was on heart valve surgery,and only Seong Wook Hong's study was on young patients.In the subgroup analysis of elderly patients,abdominal surgery,and orthopedic surgery,the average intraoperative cerebral oxygen saturation in patients with POCD was significantly lower than those without POCD(p<0.05).ConclusionPostoperative cognitive impairment is a common complication after general anesthesia.This meta-analysis included a total of 7 articles to assess the relationship between POCD and intraoperative rSO2 changes.The results showed that postoperative cognitive dysfunction was associated with a decrease in intraoperative cerebral oxygen saturation,and the average rSO2 value in patients with POCD was less than those without POCD.This study provides a new theoretical basis for the stabilization of cerebral oxygen saturation in the prevention and treatment of postoperative cognitive dysfunction.