Study On The Relationship Between Postoperative Pain And Postoperative Delirium In Elderly Patients After Laparotomy

Objective:1.Research the incidence of postoperative delirium in elderly patients after laparotomy;2.To explore the effect of postoperative pain,pain category and pain relief time on postoperative delirium in elderly patients after laparotomy.Methods: A total of 180 elderly patients who underwent elective laparotomy in hepatobiliary surgery from January 2018 to January 2019 were collected.Obtain the consent of the patient and his family,sign the informed consent form upon admission.Patients with pre-operative delirium,cognitive impairment and depression were assessed and excluded by Self-rating Depression Scale(SDS),Mini-Mental State Examination(MMSE),and the Confusion Assessment Method(CAM).Patients who met the inclusion criteria were taught to self-report pain scores using the Numerical Rating Scale(NRS)at admission and 1 day before surgery,collect general information of patients.Self-RatingAnxiety Scale(SAS)was used to assess whether patients had anxiety before surgery.The patients were evaluated for pain and delirium at2,6,10 h,9:00am,17:00pm and 21:00pm from 1 to 5 days after surgery.The patient's anesthesia grade,operation site,operation grade,operation time and the value of C-reactive protein on the first day after surgery were collected by consulting the anesthesia record,operation record and examination report.The data included in the case were sorted out,used SPSS17.0 software forstatistical analysis,the counting data in statistical analysis are expressed in frequency and percentage,Pearson/Fisher chi-square test or Fisher exact probability method was used for comparison between groups;The mean standard deviation was used to describe the measurement data conforming to normal distribution,the t test of independent samples was used to compare between groups,the median and quartile were used to describe the non-normal distribution data,and the rank sum test was used to compare between groups.In order to evaluate the effect of pain,pian type,duration of pain relief on delirium,Principal Component Analysis was used to reduce the dimension of pain score,and the first principal component was extracted.The first principal component was substituted into the multi-factor Logistic regression Model to evaluate the effect of pain on delirium.Results: Delirium was found in 19 out of 180 elderly patients after laparotomy,the incidence rate was10.6%.The results of univariate analysis showed that the age(P<0.001),marital status(P =0.014),sleep time(P<0.001),anesthesia grade(P<0.001),one day after operation(P<0.001)were significantly different between delirium and non-delirium patients.Pain scores were compared between the delirium group and the non-delirium group,the results showed that there were significant differences in resting pain score(P<0.05)from 2 hours to 3 days,active pain score(P<0.05)from 6 hours to 1 day,and 3 days.The first principal component was extracted by Principal Component Analysis and replaced by multiple logistic regression model.After controlling for theinfluence of confounding factors,the results showed that the influence of pain on delirium was statistically significant Postoperative pain is an independent risk factor for delirium in elderly patients.The higher the degree of pain,the higher the risk of delirium.In the analysis of the effect in pain on delirium,the relationship between rest pain and the risk of delirium was stronger.The higher the score of rest pain,the higher the risk of delirium(OR=2.876,95%CI:1.363~6.067).In the analysis of the influence of pain relief time on the risk of delirium,it was concluded that the rest pain relief time was the influence factor of delirium.The longer the resting pain is relieved,the higher the risk of delirium.Conclusion:Postoperative delirium is a common complication after open surgery in the elderly,which seriously affects the postoperative outcome of the patients.According to the observational study of 180 elderly patients,pain is an important risk factor for delirium.The higher the degree of pain,the higher the risk of delirium.There was a stronger association between resting pain and the risk of delirium.The higher the resting pain score,the greater the risk of delirium.The longer the resting pain lasts,the higher the risk of delirium.Therefore,pain management should be done as soon as possible after open surgery in elderly patients to prevent delirium.