Effects Of Protective Lung Ventilation On Cerebral Oxygen Metalbolism And Postoperative Delirium In Elderly Patients Undergoing Laparoscopic Surgery

Objective With the improvement of laparoscopic techniques,the development of instruments,the perioperative anesthesia management and the continuous improvement of general support,laparoscopic surgery has been greatly promoted in clinical practice.The pathophysiology of the elderly and young people are different.As the elderly often have a variety of underlying diseases,they can afford anesthesia and surgery to be weaker,the incidence of cerebral ischemia and hypoxia is higher during perioperative period.They can have immediate or long term complications,such as postoperative delirium(POD).During laparoscopic surgery,CO2 pneumoperitoneum has a greater impact on elderly patients with poor reserve capacity.It will change the body circulation,breathing and internal environment.In this study,elderly patients took lung protective ventilation strategy and intravenous anesthesia undergoing laparoscopic surgery,monitored cerebral oxygen saturation all the time and collected blood samples for brain oxygen detection in some time.The aim of this study is to investigate effects of protective lung ventilation on cerebral oxygen metalbolism and postoperative delirium in laparoscopy in elderly patients.Methods Choose sixty patients of ASA ?or?,aged 65-80 yr,BMI 18~24kg/m2,undergoing elective laparoscopy lower abdominal surgery under general anesthesia.They were randomly divided into 2 groups.One group named protective lung ventilation group(group P),the other group named routine ventilation group(group N).Each group made up of 30 patients.In group P,VT=6-8ml/kg,RR=12bpm,I:E=1:2,PEEP=5cm H2 O and interval of 15 min for regular alveolar anaplasty in surgery,while in group N,VT=10-12ml/kg,RR=12bpm,I:E=1:2.Blood samples were taken from the radial artery and jugular bulb for blood gas analyses at 10 min(after tracheal intubation),50 and 100 min(after CO2 entered the abdominal cavity)and 10 min(after CO2 out of the abdominal cavity)(T0-3).Pa O2,Pa CO2 and Sjv O2 were calculated at the same time.Cerebral oxygen saturation(r SO2)was monitored all the time.Postoperative delirium was assessed by CAM-CR at 1d,2d and 3d after operation.Results There were no difference between two group patients in terms of age,gender composition,BMI,ASA classification,educational level composition,Hb,pneumoperitoneum time and operation time.Compared with group N,Pa CO2,Sjv O2 and r SO2 were significantly increased,and Pa O2 were significantly decreased at T1-3,the incidence of postoperative delirium decreased after operation(P<0.05).Compared with the baseline value at T0,Pa O2,Pa C02,Sjv O2 and r SO2 were significantly increased.Conclusions In surgery lung protective ventilation strategy is through a small tidal volume ventilation,improve PEEP reach 5cm H2 O and intermittent pulmonary recurrent.Protective lung ventilation can reduce cerebral oxygen metabolism,improve the monitoring value of local cerebral oxygen saturation,improve brain tissue oxygenation during laporoscopic surgery and reduce postoperative delirium and improve postoperative satisfaction in the elderly patients.