Analysis Of Risk Factors In Orthopedic Perioperative Acute Ischemic Stroke

Objective: Perioperative acute ischemic stroke(PAIS) is a relatively rare but devastating complication of general surgery, but few data are available in orthopedic surgery. The aim of this study was to investigates the risk factors of PAIS in the orthopedic surgery patients.Methods: Retrieved the original medical records of patients undergoing orthopedic surgery and who with the diagnosis of ischemic stroke at the Third Affiliated Hospital of Hebei Medical University between December 2004 and December 2014 by searching the computerized database of hospital. We identified 223 patients with PAIS as PAIS group, and selected 230 control patients undergoing similar procedures at the same time but without a recorded acute ischemic stroke as the control group. All patients of the PAIS group were classified into subtypes: Large-artery atherosclerosis(LAA), Small-artery disease(SAD), Cardio embolism(CE) and Stroke of other undetermined etiology(SOE) using the TOAST classification system. Inclusion criteria:①, Older than 18 years old;② Acute onset of new focal neurologic deficit of cerebral origin persisting than 24 h and confirmed by cranial CT or MRI;③ Diagnosis in line with the diagnostic criteria revised by the fourth national cerebrovascular disease conference. Exclusion criteria: ① Diagnosis not confirmed by neurological consultation or no radiological report. The patient date were collected from medical records included patient age, sex, medical history of hypertension, diabetes, cerebrovascular disease, heart disease, atrial fibrillation and kidney disease, preoperative and perioperative usage of antithrombotic drugs, preoperative blood pressure, electrocardiography, type of anesthesia, intraoperative blood pressure change, the timing of stroke onset and neuroimaging report. Data were analyzed using SPSS13.0.Differences in patient characteristics between the cases and controls, and in patients with the different stroke subtypes were compared using the chi-square test. Multiple comparison using chi-square segmentation method; Multivariate logistic regression was performed to identify independent predictors of PAIS or the stroke subtype. P<0.05 were considered significant for all analyses.Results:1 Demographic data of patients with PAIS.A total of 230 cases of orthopedic patients with PAIS ware identified during the study period. Excluded were 7 patients who no cranial CT or MRI records, leaving 223 patients for the current analysis. Among 223 PAIS patients, 127(57.0%) patients were male, 96(43.0%) patients were female, 67(30.0%) patients with the aged ≤65 years old, 156(70.0%) patients aged >65 years old. 130(58.3%) with hypertension, diabetes in 77 cases(34.5%),history of cerebrovascular disease in 54 cases(24.2%),heart disease in 110 cases(49.3%), kidney disease in 26 cases(11.7%).Preoperative atrial fibrillation in 43 cases(19.3%), general anesthesia in 119 cases(53.4%), local anesthesia in 104 cases(46.6%), intraoperative hypotension in 157 cases(70.4%). Onset time of PAIS: occurred within 24 hours postoperation had 59 cases(26.5%),24 hours to 48 hours had 63 cases(28.3%), 48 hours to 1 week had 57 cases(25.6%), more than 1 week had 44 cases(19.7%).According to the TOAST classification system large-artery atherosclerosis in 105 cases(47.1%), small-artery occlusion in 41 cases(18.4%), cardio embolism in 51 cases(22.9%) and stroke of other undetermined etiology in 26 cases(11.7).2 Demographic data of patients in the control groupAmong 230 patients, 126(51.7%) patients were male, 104(48.3%) were female, 205(89.1%) patients with the aged ≤65 years old, 25(10.9%) patients aged >65 years old. 106(46.1%) with hypertension, diabetes in 64 cases(27.8%), history of cerebrovascular disease in 22 cases(9.6%),heart disease in 69 cases(30.0%), kidney disease in 21 cases(9.1%).Preoperative patients with atrial fibrillation in 17 cases(7.4%), general anesthesia in 127 cases(55.2%), local anesthesia in 104 cases(44.8%), intraoperative hypotension in 64 cases(27.8%).3 Comparison between PAIS groups and control groupsCompared to patients of control group, those with PAIS were older and more often had hypertension,history of cerebrovascular disease, heart disease, atrial fibrillation and intraoperative hypotension(P<0.05).There was no difference in gender, history of diabetes, kidney disease and type of anesthesia between patients and controls(P>0.05).4 Comparison of the patients with different stroke subtypesThe SOE group was not included in the statistical analysis because of the small number of cases. Comparison among the three stroke subtypes revealed that hypertension, history of heart disease, atrial fibrillation, intraoperative hypotension were statistically different(P<0.05). No statistical difference was found in other indicators in each group(P>0.05). The LAA group had the highest percentage of intraoperative hypotension, it was 84.5%.The SAD group had the highest percentage of hypertension(75.6%).The percentage of atrial fibrillation was the highest in the CE group, it was 84.3%.Logistic regression analysis showed intraoperative hypotension was independent predictor of LAA, hypertension was independent predictor of SAD.5 Analysis of predictors of PAISMultivariate logistic regression analysis showed age old than 65 years old(OR 21.5,95% CI 11.95-38.89), history of cerebrovascular disease OR 2.65,95% CI 1.29-5.41), heart disease(OR 2.43,95% CI 1.41-4.18), atrial fibrillation(OR 4.17,95% CI 1.86-9.35), and intraoperative hypotension(OR 5.76,95% CI 3.38-9.83) were independent predictors of orthopedic perioperative acute ischemic stroke.Conclusions:1 Orthopedic perioperative ischemic stroke most commonly occur in patients with age over 65 years old, previous history of hypertension, cerebrovascular disease, heart disease and atrial fibrillation.2 perioperative ischemic stroke in the orthopedic surgery patients predominantly occurred within 48 h postoperation and 80% within one week.3 The most common type of orthopedic perioperative ischemic stroke was LAA, followed by SAD and CE. Intraoperative hypotension was the independent risk factor of LAA.4 Age over 65 years old, atrial fibrillation, preoperative history of cerebrovascular disease, heart disease and intraoperative hypotension were the risk factors for perioperative ischemic stroke in patients undergoing orthopedic surgery.