The Influence Of Edaravone For Heart Surgery Patients In Postoperative Cognitive Function

BackgroundPostoperative cognitive dysfunction (POCD) refers to a functional decrease in cognition, personality and social activities after anesthesia and surgery with clinical manifestations of dysfunction in memory, attention, orientation, language, thinking as well as social behavior. POCD not only make the delay of postoperative rehabilitation and increase costs of health care, but also have other complications associated with treatment and recovery. So researches the prevention of POCD have important clinical benefit.The mechanism of POCD is still unclear:there is no effective prevention measure too. It is affected by a lot of factors, mainly including:the elderly, heart surgery, diabetes, cerebrovascular disease, postoperative infection and the lower education degree. The incidence of POCD is far higher in cardiac surgery patients. At short-term (two weeks) after surgery, the rates of cognitive dysfunction as high as26%～61%, and long-term (one month) the incidence also has5%～31%.At present, the clinical diagnosis of POCD is mainly by neuropsychological test. Specificity of other examination is poor and can not be used for POCD diagnosis. However, how to carry out neuropsychological test is disagreement. In China, we mostly used some simple cognitive assessment scale; the disadvantage is the project contents are too simple, and not enough to reflect the cognitive status of patients. So the results are debatable. In foreign, the diagnosis of POCD is requiring more meticulous and often chooses many scales. This method is more meticulous and overall evaluation cognitive functions. But the defect is the process of assessment complex, and the time-consuming too long. Patients, especially one week after operation, whether can finish the whole assessment process is suspect due to the weak body. And. with the increase of assessment scale, sensitivity of checkout POCD is increasing, but the first kind of error is increasing obviously too. Therefore, the reliability of this method is also questionable.Loewenstein occupational therapy cognition assessment battery (LOTCA) is not only for comprehensive evaluation of patients with cognitive function, but also design simple. Time consuming is about30minute. It seems to be the ideal assessment scale of POCD. But there is no clinical application at present:its validity will require further validation.ObjectiveTo investigate the clinical efficiency of LOTCA (Simplified Chinese Version, the2nd Edition) on the evaluation of POCD in patients went through cardiac valve replacement. In addition, a correlation analysis with LOTCA and MMSE was performed. So we judge whether LOTCA can use for clinical neuropsychological test for POCD. This study provides an appropriate assessment tools for the evaluation of POCD.MethodsThirty patients with no mental disorder and/or organ dysfunction went through cardiac valve replacement were included in this study. MMSE and LOTCA were performed1d before the surgery and7d after the surgery. The MMSE testing score, LOTCA testing score and its corresponding subprojects including orientation, visual and spatial perception, executive functions, visual motor organization, thinking and attention were determined, respectively. A comparative study was performed between the testing scores obtained on the7d after surgery and1d before the surgery. For the LOTCA analysis, hypofunction was designated in the presence of a decrease of one or more standard deviation. POCD was designated provided that≥2items showed decrease. For the MMSE analysis, patients were diagnosed with POCD provided that a decrease of standard deviation≤1. SPSS11.0Software was used for the statistical analysis. A Student's t test was used for the inter-group comparison. Chi square test was used for the numeration data. Spearman rank correlation analysis was performed for the correlation among all the indices. P<0.05demonstrated significant statistical difference.Results1. Among the30patients,13(43.3%) were diagnosed with POCD with MMSE while17(56.7%) were diagnosed with POCD with LOTCA. No statistical difference was noted (χ2=1.067, P=0.302).2. A strong correlation was detected between the test scores of MMSE and LOTCA (y=0.711, P<0.01). In addition, the correlation among MMSE, LOTCA and its corresponding subprojects were also investigated.3. Significant decrease of the test scores of MMSE, LOTCA. Four of its seven aspects including executive functions, visual motor organization, thinking and attention was noted on the7d after surgery compared with these obtained Id before the surgery (P<0.05).4. Compared with the scores obtained1d before the surgery, significant difference was noted between the MMSE testing time on the7d after surgery (12.27±5.137min vs9.902±3.619min, P<0.05). For the LOTCA analysis, significant difference was noted between the testing time on the7d after surgery compared with those obtained1d before the surgery (36.27±11.26min vs28.25±8.778min, P<0.01).Conclusion1. This study suggested that LOTCA applicable for POCD diagnosis and evaluation. Compared with other methods, LOTCA not only effective assessed the cognitive function in patients, but also the assessment provided a concise process. LOTCA was a more ideal neuropsychological assessment method.2. For the seven subjects during LOTCA. the major functional decrease was noted in Motor Praxis, Visuomotor Organization, Thinking Operations, Attention and Concentration on7d after surgery compared with those obtained on Id before surgery. It seemed to indicate the more complex abstracts of cognitive function maybe greater decline.3. The testing time on the7d after surgery was significantly longer than1d before the surgery maybe related to the weak of patients.4. The time of assessment with LOTCA is still longer than MMSE; some patients should complete assessment in twice because of weak. But compared with using multiple scale in foreign, the time of assessment with LOTCA is still acceptable. BackgroundPOCD in heart surgery patients was happening at higher risk. However, we still didn't know the reason of it. We always think that cardiopulmonary bypass (CPB) process was playing an important role. However, further research didn't support this view. Recent studies suggested that POCD maybe caused by systemic inflammatory response syndrome and unbalance of brain temperature in rewarming process during CPB. But there were many opposite views too. The reason of it remained to be further research.POCD not only delayed postoperative rehabilitation and increased the costs of health care, but also had other complications associated with treatment and recovery. So the researches of prevented POCD have important clinical benefits.While there were many researches tried to look for a way to decrease the risk of POCD in heart surgery patients, but we still didn't find effective ways to solve the problem. Edaravone is a kind of oxygen free radical scavenger, mainly used on the patients of nervous system disease. A large number of researches indicated that edaravone could significantly improve cognitive function in cerebrovascular disease and brain injury patients. Therefore, this study hopes to research whether edaravone can improve postoperative cognitive function and reduce the incidence of POCD in heart surgery patients.ObjectiveResearched the influence of postoperative cognitive function by edaravone for heart surgery patients, and discussed whether it can improve postoperative cognitive function and reduce the incidence of POCD in heart surgery patients. MethodsSixty patients scheduled for elective heart valve replacement were recruited to participate in this clinical trial from March2011to Augest2011,randomly divided into two groups, namely Edaravone Group(E Group) and Control Group (C Group), each group had30patients. According to the principle of double blind, the grouping process was by a specially-assigned person, the test drugs prepared by the specially-assigned person too. In E Group, edaravone (1.0mg·kg-1) diluted into100ml with normal saline, and otherwise normal saline100ml used for patients in C Group. Researcher pumped50ml test drug in30minutes after the induction of anaesthesia and the begining of CPB respectively. All of patients were collected3ml radial artery blood at Before induction (T1). End of surgery (T2),1hour after surgery (T3),6hours after surgery (T4) and24hours after surgery (T5). The blood samples stored in the refrigerator at-20℃. the serum content of1L-6, TNF-α, Aβ1-40was detected by immune sandwich double antibody elisa method.All of patients were tested with LOTCA in1day preoperation.7days postoperation and3months postoperation. and record the corresponding results. Recorded total score of LOTCA and scores of seven subprojects (Orientation, Visual Perception, Spatial Perception, Motor Praxis, Visuomotor Organization, Thinking Operations and attention and concentration) of all patients in every times. Calculated standard deviation of the1day preoperation of LOTCA total score and seven subprojects scores, the scores of7days or3months postoperation reduced equal or than one standard deviation were diagnosed impairment in this time period, and two or more impairment were diagnosed POCD.SPSS11.0was use to statistical analysis. Measurement date compared with t-test and count date compared with chi-square test (Fisher's exact test). Statistical significance was set at P<0.05.Results1. No significant difference was noted of the patients' general situation between two groups. 2. Compare with diagnostic rate of POCD:At7days postoperation, one patient died in C group and two patients were lost in E group (29vs28), the diagnostic rate of POCD was no significant difference between two groups (13vs11, P=0.601). At3months postoperation,2patients lost once more(refused testing) in C group and3patients lost once more (one died and two refused testing) in E group (27vs25), the diagnostic rate of POCD was no significant difference between two groups (6vs5, P=0.732)3. Compared the contents of IL-6, TNF-α, Aβ1-40in serum:The contents of IL-6and TNF-a were no significant differences at T1and T2between two groups. But at T3. T4and T5, E group were lower than C group, the differences between two groups had statistically significant. The contents of Aβ1-40were no significant differences between two groups at T1, T2, T3,T4and T5.Conclusion1. Edaravone used intraoperative can not improve the postoperation cognitive function in cardiac valvular surgery patients.2. The contents of Aβ1-40were no significant differences between two groups also showed that edaravone was no obvious effect in improving the postoperation cognitive function in cardiac valvular surgery patients.3. Edaravone used intraoperative can reduce the serum levels of inflammatory factors. it can reduce the postoperative systemic inflammatory response syndrome. But the reduction of systemic inflammatory response syndrome did not improve the cognitive function after surgery. It showed that mechanism of POCD was very complex. Inflammatory factors were not indicators to assess cognitive status of patients.