The Relationship Between RSO₂ And Postoperative Delirium Undergoing Laparoscopic Rectal Cancer Surgery In Elderly Patients

Ojective:Postoperative delirium（POD）is an acute change of consciousness,characterized by anxiety personality changes and memory impaired,acute brain dysfunction syndrome that occurs frequently in the elderly patient,usually occurred in 1-3 days after surgery.The purpose of this study was to identify the change of rSO₂ and serum S100A8,S100A9 and S100A12changes in elderly patients during operation,to explore the relationship between rSO₂,serum S100A8（calgranulin A）,S100A9（calgranulin B）,S100A12（calgranulin C）and postoperative delirium in the elderly patients with laparoscopic colorectal cancer surgery,to get new indicator to predict the occurrence of POD and early prevent POD.Methods:85 elderly patients undergoing laparoscopic radical resection of rectal cancer under general anesthesia wereselected.Patientgeneralcharacteristics（age,gender,height,weight,ASAclassificationandpreoperative examination report）were recorded before operation.One day before the operation,the awareness and cognitive status of thepatients were evaluated by Minimum Mental State Examination（MMSE）.Standard general anesthesia was induced with intravenous fentanyl,propofol,cis-anquamonium.tracheal intubation was performed.Mechanical ventilation was adjusted to maintain an end-tidal CO₂ partial pressure(P_ETCO₂)ranging between 32 and 37 mmHg.General anesthesia was maintained with sevoflurane.Non-invasive blood pressure（BP）,blood oxygen saturation（SpO₂）,electrocardiogram（ECG）,heart rate（HR）,eeg bispectral index（BIS）and cerebral oxygen saturation（rSO₂）were monitored.The mean arterial pressure（MAP）,P_ETCO₂,ECG,BIS and rSO₂ during 10 min after endotracheal intubation（T1）,15 min after the pneumoperitoneum（T2）,pneumoperitoneum+head low 1 h（T3）,pneumoperitoneum+head low2 h（T4）,at the end of pneumoperitoneum（T5）and in horizon position at 10 min after deflation（T6）were recorded.Intraoperative pneumoperitoneum time,head low time,operation time,blood loss,transfusion amount,time ofwake up（from drug withdrawal to the time of open eye）and extubation time（from drug withdrawal to extubation）.At 5min before induction of anesthesia（TS1）,immediately after extubation（TS2）,24h after surgery（TS3）,peripheral blood samples were taken,the serum S100A8,S100A9 and S100A12 concentration were measured by enzyme combined adsorption method.pain score（Price-Henry）was recorded on theday 1,day 2 and day 3 after surgery pain score,The Confusion Assessment Method for the Intensive Care Unit（CAM-ICU）was used to assess the occurrence of POD in all patients.According to the result of CAM-ICU,patients were divided into delirium group（group D）and non-delirium group（N group）.rSO₂ values beyond the normal range（the normal range of rSO₂ is 60%⁹0%,and the absolute value of rSO₂is greater than 90%or less than 60%,above or below 20%of the base value）were recorded.The relationship between rSO₂,serum S100A8,S100A9,S100A12 and POD was discussed.Result:1.Among the 85patients with laparoscopic radical resection of rectal cancer,15 patients developed POD after the operation,the incidence was 17.6%.2.Compared with the general characteristics of the two groups of patients preoperative and intraoperative period,there were no significant difference between D group and N group in the gender,weight,height,ASAgrade,hemoglobin,serumalbumin,operationtime,pneumoperitoneum time,head low,awake time,extubation time,infusion and blood loss（P>0.05）.In the D group,age was significantly older than that of N group,and the difference was statistically significant（P<0.05）.3.MAP,P_ETCO₂ was increased significantly at T2,T3,T4,T5,T6compared with that at T1 in both groups,the difference was statistically significant（P<0.05）.In the D group,P_ETCO₂ was increased at T5 and T6 than that of the N group,and the difference was statistically significant（P<0.05）.4.rSO₂ was increased significantly at T2,T3,T4,T5 compared with that atT1in both groups,the difference was statistically significant（P<0.05）.In the D group,rSO₂ was increased at T5 than that of the N group,and the difference was statistically significant（P<0.05）.There were significant difference in the maximum value,relative increase value and maximum increase value of rSO₂,the case of rSO₂ over 90%between the two groups（P<0.05）.5.Serum S100A8,S100A9andS100A12concentrationwereincreased significantly immediately after extubation（TS2）,24 h after surgery（TS3）compared with that at 5min before induction of anesthesia（TS1）in both groups,the difference was statistically significant（P<0.05）.In the D group,Serum S100A8,S100A12 concentration were increased significantly immediately after extubation（TS2）,24 h after surgery（TS3）than that of N group,and the difference was statistically significant（P<0.05）.The Serum S100A9 concentration at 24 h after surgery（TS3）in D group was increased than that of the N group,and the difference was statistically significant（P<0.05）.6.BIS was declined significantlyat15minafterthepneumoperitoneum（T2）,pneumoperitoneum+head low 1 h（T3）,pneumoperitoneum+head low2 h（T4）,at the end of pneumoperitoneum（T5）,inceased in horizon position at 10 min after deflation（T6）compared with that at 10 min after endotracheal intubation（T1）in both groups,the difference was statistically significant（P<0.05）.Pain score reduced significantly on the day 2 after the operation,the day 3 after the operation compared with that on the day 1 after the operation in both groups,the difference was statistically significant（P<0.05）.Pain score reduced significantly on the day 3 after the operation compared with that on the day 2 after the operation in both groups,the difference was statistically significant（P<0.05）.Conclusion:1.Carbon dioxide pneumoperitoneum for long time and Trendelenburg position with head low at 15 degrees,rSO₂ values,S100A8,S100A9 and S100A12 in serum in elderly patients undergoing laparoscopicrectalcancersurgeryincreasesignificantly,and up-regulation of.2.Age,rSO₂ value,intraoperative and postoperative24h serum inflammatory factor S100A8,S100A9,S100A12 protein concentration correlated with the occurrence of POD in elderly patients undergoing laparoscopic rectal cancer surgery.3.For laparoscopic colorectal cancer surgery in elderly patients with general anesthesia,using the rSO₂ monitoring technology may provide an accurate and individualized anesthesia management basis for anesthesiologists to reduce the occurrence of POD.