The incidence and risk factors of postoperative delirium in patients undergoing total knee arthroplasty / 临床麻醉学杂志

ABSTRACT

Objective To explore the incidence and risk factors for postoperative delirium patients over 60 years undergoing total knee arthroplasty.Methods Three hundred and sixty-nine patients (73 males,296 females,aged over 60 years,ASA Ⅰ or Ⅱ) undergoing unilateral total knee arthroplasty were chosen.Before induction of anesthesia,femoral nerve block by nerve stimulator was performed for all patients,25 ml of 0.4% ropivacaine was injected to the continuous femoral nerve catheter for postoperative analgesia,all patients received intravenous-inhalation anesthesia during the operative.The confusion assessment method-intensive care unit (CAM-ICU) was used twice a day to evaluate whether the postoperative delirium had happened for patients within 3 days after operation,and record the case of complication besides postoperative delirium.To analysis the perioperative indicators depend on whether the postoperative delirium had happened for patients,then to screen out the probable risk factors for postoperative delirium,which include the kind of intravenous anesthesia drugs during operation,gender,age group,level of education;preoperative hypertension,coronary heart disease,arrhythmia,stroke,respiratory disease,diabetes,abnormal renal function and the ASA grade;the bleeding and blood transfusion volume during operative and the total amount of blood transfusion;degree of postoperative pain and whether used pethidine after operative.Put all observed factors to be analyzed by the Logistic regression model.Results Sixty-two patients (16.8%) had delirium within 3 days after operation.The results of multi-factor Logistic regression analysis indicates that the patients` increasing age (OR=2.116,P=0.035),low level of education (OR=0.091,P<0.001),preoperative chronic obstructive pulmonary diseases (COPD) (OR=12.500,P=0.002),high ASA grade (OR=22.333,P=0.005),increasing total amount of blood transfusion (OR=4.500,P<0.001) and postoperative used pethidine(OR=22.372,P=0.001) were the independent risk factors for postoperative delirium.Conclusion The patients` age,level of education,preoperative COPD,high ASA grade,increasing total amount of blood transfusion and postoperative used pethidine are the independent risk factors for postoperative delirium.