Mild Cognitive Impairment In Geriatric Patients Before Thoracic Surgery And Its Effects On Postoperative Outcomes

Part Ⅰ: Research progress of perioperative neurocognitive disorders in elderly patientsElderly patients have a higher incidence of preoperative cognitive impairment,which is associated with an increased risk of postoperative delirium and cognitive dysfunction,leading to longer hospital stays,increased medical costs,reduced quality of life,and increased patient prevalence and mortality.Therefore,it has become an important topic of perioperative medicine to pay more attention to the preoperative cognitive impairment of elderly patients.In order to improve people’s attention to the perioperative neurocognitive disorders in elderly patients,and to analyze the potential predictors,this study will review the previous literature from the aspects of neuropsychological test,cerebral oxygen saturation monitoring,neuronal damage markers detection,imaging and EEG examination,so that we can carry out risk stratification for high-risk patients and take effective interventions.Part Ⅱ: Efficacy of preoperative cerebral state index predicting cognitive function in elderly patientsObjective: To observe the incidence of preoperative cognitive impairment of elderly patients and explore whether the cerebral state index(CSI)based on EEG could be used for cognitive function.Methods: A total of 105 patients undergoing elective thoracic surgery,54 males and51 females,aged 65-80 years,BMI 18-30 kg/m2,ASA physical status I-III,were involved in the study.Brain function assessment and Chinese modified version of Montreal cognitive function(MoCA)tests were performed before surgery.According to MoCA test,the patients were divided into normal group(MoCA≥26 scores,group N)and abnormal group(MoCA<26 scores,group AN).Regarding the results of MoCA scale tests as the gold standard,logistic regression equations were established based on CSI(brain chaos,internal concentration,brain introversion,memory processing,reaction speed)in elderly patients.The cognitive index was calculated.Receiver operating characteristic(ROC)curve and area under the curve(AUC)was used to evaluate CSI to differentiate the cut-off points and efficacy of CI for predicting the cognitive impairment.Results: The incidence of cognitive impairment in elderly patients before thoracic surgery was 47.6%(50/105).A model based on cognitive index could diagnose preoperative cognitive impairment in elderly patients.(AUC=0.699,95% CI,0.563-0.835,P=0.007),with a sensitivity of 66.7% and a specificity of 69.2%.Conclusion: The prevalence of undiagnosed probably mild cognitive impairment among elderly patients scheduled for thoracic surgery was higher(49%).Preoperative cerebral state index based on EEG extraction could predict cognitive function impairment and provide a new choice for preoperative cognitive function assessment.Part Ⅲ : Impact of mild cognitive impairment on postoperative clinical outcomes in geriatric patients during thoracic surgery Background: The prevalence of undiagnosed mild cognitive impairment(MCI)in elderly patients scheduled for thoracic surgery and its association with adverse clinical outcomes is still unproven.Methods: We enrolled 170 patients 65 year of age or older who were scheduled for thoracic surgery.82 males and 88 females with ASA grade II-III.All the elderly patients were performed with Chinese modified version of MoCA preoperatively.According to the results,they were divided into normal group(MoCA≥26 scores,group N)and abnormal group(MoCA<26 scores,group AN).Outcomes included the incidence of POD(primary outcome),postoperative pulmonary complications(atelectasis,pulmonary infection,respiratory failure),cardiovascular complications(new arrhythmia,myocardial infarction and acute cerebral infarction),other complications(blood transfusion,chylothorax),ICU stay and the hospital length of stay(secondary outcomes).Data were analyzed using univariate and multivariate analyses.Results: The incidence of MCI before thoracic surgery in elderly patients was49.4%(76/154).Compared with group N,MCI could increase the incidence of POD(14.1% vs 30.3%,P=0.016)and median LOS(4 vs 5d,P=0.016).However,the differences in pulmonary complications,cardiovascular and other complications,ICU stay were not significant.Multivariable logistic regression analysis showed that preoperative MCI was associated with higher rate of POD(OR=2.573,95%CI=1.092 to 6.060,P=0.031).Besides,compared with the elderly patients without postoperative delirium,postoperative delirium could increase the risk of postoperative pulmonary complications(17.5% vs 35.3%,P=0.026),and increase the median length of hospital stay(4 vs 5d,P < 0.001).Conclusion: Mild cognitive impairment was associated with higher rate of POD and prolonged the hospital length of stay,while it was not possible to conclude that it was related to the incidence of pulmonary complications,cardiovascular and other complications after thoracic surgery.Moreover,postoperative delirium could increase the risk of postoperative pulmonary complications and prolong the length of hospital stay.Therefore,we should pay more attention to the preoperative cognitive function evaluation of the elderly patients,and provide more nursing for the rehabilitation of the high-risk group during the perioperative period.Part 4 Impact of paravertebral blockade use in geriatric patients undergoing thoracic surgery on postoperative adverse outcomes Background: While it is known that thoracic paravertebral blockade(TPVB)could reduce pain undergoing thoracic surgery,it has not been confirmed whether this reduction in pain reduces pulmonary complications in an elderly population Methods: We performed a monocentric retrospective analysis for prospectively collected 65 years or older patients receiving thoracic surgery with or without intraoperative TPVB between November 7,2018 and April1,2019,at Shanghai Chest Hospital.Chest wall resection,bilateral lung resection,conversion to thoracotomy and ipsilateral reoperation were excluded.A total of 154 elderly patients with lung operations were included in the final analysis,34 of whom received general anesthesia combined with TPVB(GA-TPVB).The primary outcome was the incidence of postoperative pulmonary complications(PPCs).The secondary outcomes were the incidence of cardiovascular and other complications,required analgesia in post anesthesia care unit(PACU),patient controlled analgesia(PCA)pressing frequency in 24 h,ICU stay and the hospital length of stay(LOS).Results: The incidence of PPCs undergoing thoracic surgery was about 21.4%(33/154).Compared with GA,GA-TPVB could reduce the incidence of PPCs(25%vs 9%,P=0.042),mostly reduce postoperative atelectasis(19% vs 3%,P=0.021).TPVB could reduce the rate of required analgesia in PACU,PCA pressing frequency in 24 h and chest tube duration.However,there were no significant differences on the rate of cardiovascular and other complications,ICU stay and LOS between the two groups(P>0.05).Multivariable logistic regression analysis identified preoperative DLCO% ≥92%(OR =0.293,P=0.006),duration of surgery <75 min(OR =0.278,P=0.008)and GA-TPVB(OR =0.270,P=0.048)was associated with fewer PPCs.Conclusion: Our study shows that general anesthesia combined with TPVB may reduce PPCs by reducing postoperative pain in geriatric patients undergoing thoracic surgery compared with general anesthesia alone.