Effects Of Different Anesthetics On Postoperative Delirium In Elderly Patients Undergoing Laparoscopic Surgery

Objective : To investigate the effects of dexmedetomidine,midazolam and lidocaine on postoperative delirium in elderly patients undergoing laparoscopic radical resection of colorectal cancer.Methods: To select 80 patients aged 65~80 undergoing laparoscopic radical resection of colorectal cancer between December 2016 and December 2017 in the People's Hospital of Liaoning Province,the American Society of Anesthesiologits(ASA)class I~II,duration of surgery for 3~5 hours.All patients were randomly divided into four groups according to the random number table method.The four groups were dexmedetomidine group(group D),midazolam group(group M),lidocaine group(group L),and normal saline group(group C),20 cases in each group.Before anesthesia induction,the patients in group D received infusion of dexmedetomidine 0.5?g/kg,the patients in group M received infusion of midazolam 0.5mg/kg,the patients in group L received infusion of lidocaine 1mg/kg and the patients in group C received equal volume normal saline,the infusion time were all 10 min.All cases had been choosen inhalation and intravenous general anesthesia,and received propofol,fentanyl and vecuronium for induction,after that trachea intubation was performed.Maintenance of anesthesia: sevoflurane continuously inhaled combined with propofol,remifentanil continuous pump injection.The BIS value was maintained between 40 and 60 during surgery to ensure surgical safety and prevention of intraoperative awareness.During perioperative period,the patient's heart rate(HR)and blood pressure(BP)were stable,and the fluctuation range was less than 20% of the base value.All of patients use PCIA for postoperative analgesia.MAP and HR were recorded during surgery.Bleeding volume in surgery,time of operation,anesthesia time,extubation time,anesthetics dosage and postoperative VAS score were recorded in seven time points.The seven time points were T0(patients were admitted for 5 min),T1(before induction after intubation),T2(1 min after intubation),T3(before surgical incision),T4(1 min after incision),and T5(surgery 1 hour),T6(at the end of surgery).Cognitive function of all the patients was evaluated by Mini Mental State Examination(MMSE)1 day before operation and 1 day,3 day and 5 day postoperative.Results: The final number of completed trials was 78 cases,20 cases in group C,19 cases in group M,20 cases in group D,and 19 cases in group L.1.There was no significant difference among the age,sex,BMI,ASA physical status,years of education and MMSE score(P>0.05).2.There was no significant difference among bleeding volume,surgery time,anesthesia time,extubation time,anesthetics dosage and postoperative VAS score(P>0.05).3.MMSE score significantly decreased postoperatively in group C,MMSE score also decreased in group M,the difference was statistically significant(P<0.05).There was no significant difference about MMSE score in group D and L(P>0.05).4.There was no significant difference about MAP and HR among 4 groups at the point of T0(P>0.05).There was significant difference between T1-6 and T0 in four groups(P<0.05).At the same time,it was found that the fluctuateon of MAP and HR at different time points of group C was large,and the difference was statistically significant(P<0.05).In the group D,group M and group L,the fluctuation of MAP and HR at different time points was small,and the difference was not significant(P>0.05).5.Compared with group C,the morbidity of POD in group D and L was lower the day after surgery,and the difference was statistically significant(P<0.05).The morbidity of POD in group M was also lower than group C the first day after surgery.But the difference was not significant(P>0.05).The third day postoperative,there was no significant difference about the morbidity of POD in four groups(P>0.05).The fifth day postoperative,there was no significant difference about the morbidity of POD in four groups(P>0.05).Conclusion: The application of dexmedetomidine and lidocaine could reduce the morbidity of POD in elderly patients after laparoscopic radical resection of colorectal cancer.The application of midazolam made no significant effect on the morbidity of POD.