Risk Factors Of Delirium In Elderly Patients After Lower Limb Surgery

Objective: Postoperative delirium,a deleterious condition,is defined as a change in mental status that is characterized by acute and fluctuating disturbance in cognitive function,such as orientation,memory,speech,and thingking.It is common in elderly persons in the hospital,it has been associated with prolonged hospitalization,risk of comorbid conditions,impaired quality of life,and mortality rate.The aetiology is multifactorial with several well-described risk factors such as increasing age and preoperative cognitive impairment.Eliciting factors include polypharmacy,withdrawal states,electrolyte imbalances,and infection.This study analyzed risk factors of delirium in elderly patients after lower limb surgery.The purpose is to provide evidence for effective prevention measures,and find prevention and treatment in patients with high-risk,do our best to reduce the incidence of delirium,and cut down the duration of postoperative delirium.Methods: This research was a prospective observational study.The inclusion period for this research began on September,2015,and was terminated on January,2016.Our hospital had a total of 265 patients(?65years)with elective lower limb surgery.Excluded were patients who had severe hepatic and renal dysfunction,serious disorder of central nervous system or were unable to provide complete relevant data.At last this study chose 203 names of elderly patients(?65years)with lower limb surgery as the research object.Recorded the patients preoperative information(age,BMI,anemia,degree of education,anamnesis,American Society of Anesthesiologists,and NYHA functional class),and carries on the MMSE score;Recorded of the indicators(anesthesia,surgical time,anesthesia time,anesthetic dosage, hypotension,hypoxemia,liquid volume,blood transfusion,etc);Patients were followed up for 1 ~ 7 days postoperatively,CAM scale to evaluate the incidence of postoperative delirium,postoperative complications(postoperative agitation,nausea and vomiting,postoperative pulmonary complications,cardiovascular complications,etc)were also recorded.Using univariate logistic regression analysis screened factors associated with postoperative delirium.The results were entered into the multivariate logistic regression analysis,screening the high risk factors for postoperative delirium.Through the Exhaustive CHAID model to determine the continuous variables of Logistic point hierarchical regression analysis,significant test level split and merge model parameters were 0.05.Results: Among 203 patients,47 cases(23.15%)were diagnosed with Postoperative delirium,of which 13 cases(27.66%)were male,and 34 cases(72.34%)were female.The univariate logistic regression analysis showed:The factors of age,BMI,education,abnormal electrocardiogram,American Society of Anesthesiologists,NYHA functional class,preoperative hypertension,preoperative albumin level,intraoperative use of midazolam,sufentanil,dezocine,sevoflurane,and postoperative nausea and vomiting were demonstrated relationship with the occurrence of postoperative delirium.These 13 factors then turned into the multivariate logistic regression analysis.The result is :Age ? 70 years old,BMI ? 19.51,preoperative hypertension,and intraoperative use of dezocine are the high risk factors of postoperative delirium.Conclusion: Age ? 70 years old,BMI ? 19.51,preoperative hypertension,and intraoperative use of dezocine are the risk factors of postoperative delirium in elderly patients with lower limb surgery.