The Effect Of Dexmedetomidine On Postoperative Cognitive Function In Elderly Patients After Laparoscopic Colorectal Cancer Resection

Postoperative cognitive dysfunction,as a kind of mild neurocognitive impairment after anesthesia.It is characterized by nerve damage.Compared with preoperative cognitive impairment,patients’memory,concentration and information processing ability are more difficult.Symptoms include mild memory loss,even inability to information received by the brain,or seriously affects the quality of life of patients（especially elderly patients）.The purpose of this study is to observe the effect of dexmedetomidine on postoperative inflammatory factors in elderly patients undergoing laparoscopic colon cancer resection,so as to determine the effect of dexmedetomidine on postoperative cognitive function.From January 2019 to February 2020,60 elderly patients who undergoing laparoscopic colon cancer radical operation under general anesthesia were selected.There were 36 males and 24 females.The selected patients were divided into study group and control group according to the random number table method.Each group had 30 cases.Before anesthesia induction,the study group was given 1μg·kg^-l of dexmedetomidine for 10minutes.The patients were given 0.3μg·（kg·h）^-l before the end of the operation half an hour off.The control group was given 1μg·kg^-l of normal saline for 10 minutes before operation and 0.3μg·（kg·h）^-l before the end of the operation half an hour off.After the operation,good analgesia was maintained without long-acting sedative.After the operation,intravenous analgesia was used（formula:sufentanil 1ug/kg+normal saline to 100ml,infusion dose 2ml/h）.The VAS score of the rest was less than 3 points.HR,SBP and DBP were monitored before anesthesia induction（T₀）,1 day after anesthesia induction（T₁）and 3 days after anesthesia induction（T₂）.TNF-α,IL-1β,IL-6 and MIP-2 were measured at T₀,T₁ and T₂.The cognitive function of patients was evaluated by MMSE on T₀,T₁ and T₂ respectively.POCD was determined by Z-score method after MMSE.The results showed that:1.There was no significant difference between the two groups in the age,height,weight,gender,ASA grade,operation time,infusion volume,urine volume and incidence of postoperative adverse reactions.（P>0.05）;2.The systolic pressure,diastolic pressure and heart rate of the study group at T₁ time and T₂ time were lower than those of the control group.The difference was statistically significant（P<0.05）;3.The inflammatory factor TNF-αof the two groups at T₀ time.There was no significant difference in the values of IL-1β,IL-6 and MIP-2（P>0.05）.There was a significant difference in the values of TNF-α,IL-1β,IL-6 and MIP-2 between the two groups at T₁ time and T₂ time than those of the T₀time（P<0.05）.The values of TNF-α,IL-1β,IL-6 and MIP-2 in the study group at the time of T₁ and T₂ were lower than those in the control group（P<0.05）;4.There was no significant difference in the scores of MMSE scale between the two groups at T₀（P>0.05）.The scores of MMSE scale between the two groups at T₁ and T₂ were lower than those of the T₀.The difference was statistically significant（P<0.05）.5.The scores of MMSE at T₁ and T₂time in the study group were higher than those of the control group.The difference was statistically significant（P<0.05）.The incidence of postoperative cognitive dysfunction at T₂ time in the study group was lower than those of the control group.The difference was statistically significant（P<0.05）.The results of the analysis are as follows:Dexmedetomidine can improve the cognitive function of elderly patients after laparoscopic colorectal cancer resection.Its mechanism may be related to the decrease of TNF-α,IL-1β,IL-6 and MIP-2.