| Backgrounds:Postoperative stroke usually occurs within 30 days after operation,and the most common type of which is the ischemic stroke.Although the incidence of postoperative stroke is low,the disability rate and fatality rate of which are high,as one of the severe postoperative complications.Risk factors of postoperative ischmic stroke have been widely reported in fields of cardiac surgery and vascular surgery but not in the fields of non-cardiac and non-vascular surgery.And there are great differences in terms of incidence and risk factors of postoperative ischmic stroke among relative studies of non-cardiac and non-vascular surgery.The potential influence factors include different study population,types and methods of operation,anesthesia methods and research design,and so on,indicating the necessity of studies in specific population with some kind of surgery.Orthopedic diseases are common and its main treatment is operation.There is also a risk of ischmic stroke after orthopedic surgery.At present,the studies of postoperative ischmic stroke for orthopedic surgery is rare,and most relative data are from subgroup results of studies mixed with other surgeries.For example,some studies that involved different operations such as general operation,gynecologic operation,urology operation and orthopedic operation had conducted subgroup analyses about the risk factors of postoperative ischmic stroke in orthopedic operation.However,these studies may neglect the heterogeneity among different surgery types in their study design such as inclusion criteria,exclusion criteria and selection of research factors,and therefore their results may be bias.Besides,the types and locations of orthopedic surgery may also impact the risk of postoperative ischmic stroke.For example,orthopedic surgery of upper limb that did not impact walk with short bed time and fast recover,may decrease the influence of risk factors of ischmic stroke.In contrast,orthopedic surgery of low limb may be more vulnerable to the influence of the same risk factors of ischmic stroke.Hip or knee arthroplasty uses artificial joints to replace the diseased ones in order to reconstruct the normal function,which is a mature reliable treatment approach mainly for middle-aged and elderly people with relative indications.As our country has becoming an aging society,the development rate of hip or knee arthroplasty is also increased correspondingly.Because that the relative patients usually have comorbidities such as hypertension,diabetes and coronary heart disease,the risk of postoperative ischmic stroke may be increased.However,there is a lack of such studies.On the other hand,general clinical information such as preoperative or postoperative blood pressure,medical history,operation pattern and time,anaesthesia pattern and time were usually analyzed in previous studies of postoperative ischmic stroke,but results based on the whole blood cell count and blood biochemistry test were rare.However,some results from these tests are associated with the risk of ischmic stroke,and the relationship between the results of these tests and postoperative ischmic stroke is still unclear.In addition,although the mortality of postoperative ischmic stroke is high,the prognosis of ischmic stroke such as in-hospital mortality and long-term survival after hip or knee arthroplasty remains elusive.Objective:This study was to investigate the incidence,risk factors and prognosis of postoperative ischemic stroke in middle-aged and elderly patients with hip and knee arthroplasty by retrospective analyses of clinical data.Methods:From January 2010 to June 2017,2475 middle-aged and elderly patients undergoing total hip arthroplasty or knee arthroplasty were enrolled in this study.Inclusion criteria:1)patients aged more than or equal to 45 years;2)patients received total hip arthroplasty or knee arthroplasty;3)patients with complete clinical data.Exclusion criteria:1)patients aged less than 45 years;2)patients received operation other than total hip arthroplasty or knee arthroplasty;3)patients with abnormal intracranial signal diagnosed by CT or MRI as brain abscess,brain tumor,radiation induced encephalopathy,encephalitis and so on.4)patients with transient ischemic attack after operation and without ischemic stroke lesions in MRI images;5)patients with a failure of clinical evaluation because of incomplete clinical data.Data were collected,including preoperative general information:patient gender,age,height,weight,body mass index（BMI）,systolic blood pressure（BSP）,diastolic blood pressure（BDP）,American Society of Anesthesiologists（ASA）classification,previous disease history（hypertension,diabetes,coronary heart disease,stroke and arrhythmia）,and smoking and drinking history;2)preoperative results of complete blood cell count:the red blood cell counts（RBC）,Red blood cell distribution width（RDW）,hematocrit（Hct）,white blood cell counts（WBCC）,platelet counts（PLT）,and hemoglobin（Hb）;3)preoperative results of blood biochemistry test:the levels of albumin（Alb）,serum creatinine（Scr）,uric acid（UA）,plasma sodium,fasting plasma glucose,total cholesterol（TC）,triglyceride（TG）,high destiny lipid-cholesterol（HDL-C）and low destiny lipid-cholesterol（LDL-C）;4)surgery-related data:surgery types,anesthesia,duration of anesthesia,duration of surgery,and the occurrence of intraoperative hypotension;5)the occurrence of ischmic stroke within 30 days after operation;6)in-hospital mortality and long-term survival after out of hospital（telephone follow-up）for patients with postoperative ischmic stroke;7)the risk analyses for in-hospital mortality based on factors including cause of death,other common complications after arthroplasty（deep venous thrombosis of the lower extremities,local hematoma,nerve injury and fracture）,and comorbidities such as hypertension,diabetes,coronary heart disease and arrhythmia.The diagnostic criteria of ischmic stroke was according to the guideline to diagnosis and treatment of acute ischemic stroke in China by the study group of cerebrovascular disease for neurology in Chinese Medical Association:1)acute onset;2)neurological deficits due to focal cerebral ischemia（weakness or numb of face or limb on one side,language disability,and so on）or multiple neurologic deficits in minority;3)The unlimited duration time of related symptoms and signs when corresponding infarct lesions of brain confirmed by CT or MRI or a duration time more than 24 hours for related symptoms and signs without corresponding infarct lesions in brain CT or MRI images;4)exclusion of other diseases;5)the exclusion of cerebral hemorrhage by CT or MRI.According to whether the stroke occurred or not,the patients were divided into the test group and the control group.SPSS 22.0 was used for statistical analyses.Quantitative data with and without normal distribution were analyzed by variance test and non-parametric test respectively.The enumeration data were analyzed by Chi-square test.Non-conditional multivariate logistic regression were used to analysis the risk factors of postoperative stroke and the hazard ratio（HR）and its 95%confidence intervals（CIs）were calculated.The Kaplan-Meier method was used for survival analyses,and 1-and 4-year cumulative survival rate and their 95%CIs were calculated.A value of P<0.05（two sided）was regarded as statistically significant.Results:1.clinical characteristics of the test groupPostoperative ischmic stroke occurred in 25 patients（1.01%）in this study.Among them,22 events（88.00%）occurred within 1 week after operation and the other 3 events（12.00%）occurred after 1 week after operation.There were 13 males（52.00%）and 12 females（48.00%）,with a mean age of 69.65±6.84 years,a mean height of 166.86±8.12cm,a mean preoperative weight of 68.49±8.27kg,a mean preoperative BMI of 24.76±1.76kg/m2,a mean preoperative SBP of 142.71±7.46mmHg,a mean preoperative DBP of95.76±7.12mmHg.The number of subjects with preoperative ASA classification 1 and 2 were 7（28.00%）and 18（72.00%）respectively,with a history of hypertension,diabetes,coronary heart disease,arrhythmia,stroke,smoking and drinking were 13（52.00%）,5（20.00%）,3（12.00%）,6（24.00%）,3（12.00%）,10（40.00%）,7（28.00%）,respectively.For preoperative results of the complete blood cell count,the mean RBC,RDW,WBCC,PLT counts,Hb and Hct were（4.79±0.81）×1012/L,14.19±0.78%,（8.61±1.67）×109/L,（217.53±34.86）×109/L,131.48±35.46g/L and 0.42±0.09,respectively.For preoperative results of blood biochemistry test,the mean Alb,Scr,UA,plasma sodium,fasting plasma glucose,TC,TG,HDL-C and LDL-C were42.87±8.76g/L,44.62±8.49μmol/L,262.49±38.47μmol/L,138.71±3.26mmol/L,6.46±1.23mmol/L,5.06±1.13mmol/L,1.33±0.34mmol/L,1.19±0.35mmol/L and 3.61±0.49mmol/L,respectively.For surgery-related factors,the number of subjects with hip arthroplasty,knee arthroplasty,persistent epidural anesthesia and umbar-epidural-combined anesthesia were 10（40.00%）,15（60.00%）,13（52.00%）and 12（48.00%）,respectively.The mean duration time for anesthesia and operation were112.51±15.37min and 167.48±27.15min respectively.There were 2（8.00%）cases of intraoperative hypotension.2.clinical characteristics of the control groupIn a total of 2450 controls,there were 1373 males（56.04%）and 1077females（43.96%）,with a mean age of 64.48±8.37 years,a mean height of167.47±7.62cm,a mean preoperative weight of 67.74±8.59kg,a mean preoperative BMI of 24.36±1.57kg/m2,a mean preoperative SBP of136.42±8.41mmHg,a mean preoperative DBP of 91.44±6.84mmHg.The number of subjects with preoperative ASA classification 1 and 2 were 1229（50.16%）and 1221（49.84%）respectively,with a history of hypertension,diabetes,coronary heart disease,arrhythmia,stroke,smoking and drinking were647（26.41%）,116（4.73%）,217（8.86%）,144（5.88%）,98（4.00%）,515（21.02%）,441（18.00%）,respectively.For preoperative results of the complete blood cell count,the mean RBC,RDW,WBCC,PLT counts,Hb and Hct were（4.86±0.85）×1012/L,12.28±0.51%,（8.82±1.75）×109/L,（196.47±28.46）×109/L,136.82±31.71g/L and 0.39±0.11,respectively.For preoperative results of blood biochemistry test,the mean Alb,Scr,UA,plasma sodium,fasting plasma glucose,TC,TG,HDL-C and LDL-C were41.34±8.01g/L,41.63±9.35μmol/L,267.28±35.47μmol/L,139.47±3.12mmol/L,5.27±1.17mmol/L,4.84±1.06mmol/L,1.26±0.37mmol/L,1.14±0.31mmol/L and 2.76±0.36mmol/L,respectively.For surgery-related factors,the number of subjects with hip arthroplasty,knee arthroplasty,persistent epidural anesthesia and umbar-epidural-combined anesthesia were 1127（46.00%）,1323（54.00%）,1331（54.33%）and 1119（45.67%）,respectively.The mean duration time for anesthesia and operation were 107.36±11.36min and 164.62±26.41min respectively.There were 122（4.98%）cases of intraoperative hypotension.3.comparisons of clinical characteristics between the test and control groupsThere were statistically significant differences between the test and control groups in following aspects（P<0.05）:the mean age（69.65±6.84 vs 64.48±8.37years）,the mean preoperative SBP（142.71±7.46 vs 136.42±8.41mmHg）and DBP（95.76±7.12 vs 91.44±6.84mmHg）,the subjects number of preoperative ASA classification 2（72 vs 49.84%）,the proportions of subjects with a history of hypertension,diabetes,arrhythmia,stroke and smoking（52.00 vs 26.41%,20.00 vs 4.73%,24.00 vs 5.88%,12.00 vs 4.00%and 40.00 vs 21.02%,respectively）,the mean preoperative RDW,fasting plasma glucose and LDL-C level（14.19±0.78 vs 12.28±0.51%,6.46±1.23 vs 5.27±1.17mmol/L and3.61±0.49 vs 2.76±0.36mmol/L）.4.multivariate analysis for risk factors of postoperative ischmic strokeCharacteristics that were significantly different between the test and control groups（age,preoperative SBP,DBP and ASA classification,a history of hypertension,diabetes,arrhythmia,stroke and smoking,the level of preoperative RDW,fasting plasma glucose and LDL-C）were selected for non-conditional multivariate logistic regression.The results show that the advanced age,hypertension and diabetes history,preoperative RDW and LDL-C level were the independent risk factors of postoperative ischmic stroke in middle-aged and elderly subjects with hip and knee arthroplasty（P<0.05）,but the preoperative SBP,DBP and ASA classification,a history of arrhythmia,stroke and smoking,and the level of preoperative fasting plasma glucose were not（P>0.05）.5.the prognosis of postoperative ischmic strokeThere were 3（12.0%）and 5（0.20%）in-hospital deaths in subjects with and without postoperative ischmic stroke,the difference was significant（P<0.001）.The cause of death in the controls included pulmonary infection（1subject）,sepsis（1）,miocardial infarction（2）and congestive left heart failure（1）.The risk analyses for in-hospital mortality based on factors including causes of death,other common complications after arthroplasty（deep venous thrombosis of the lower extremities,local hematoma,nerve injury and fracture）,and comorbidities such as hypertension,diabetes,coronary heart disease and arrhythmia.The results show that the postoperative ischmic stroke was the independent risk factors of in-hospital mortality after total hip or knee arthroplasty in middle-aged and elderly patients,the OR was 31.22（21.45-45.31;P<0.001）.Other independent risk factors of in-hospital mortality included sepsis,miocardial infarction and congestive left heart failure,the OR were 25.219（12.62738.810;P<0.001）,79.910（21.889201.175;P<0.001）and 68.186（16.257177.601;P<0.001）。The middle follow-up time was 49months for subjects with postoperative ischmic stroke after out of hospital,and the 1-and 4-years cumulative survival rate of these subjects were 77.27%（53.74-89.85）and 50.00%（28.18-68.43）。Conclusion:1.the postoperative ischemic stroke has a low incidence but a high mortality and was an independent risk factor of in-hospital mortality in middle-aged and elderly patients with hip and knee arthroplasty.2.the independent risk factors of postoperative ischemic stroke in this population included the advanced age,hypertension and diabetes history,preoperative RDW and LDL-C level.Patients with these risk factors are needed to be observed and cared more closely after arthroplasty. |
PDF Full Text Request