To observe whether adjusting the level of intraoperative controlled hypotension through cerebral oxygen saturation monitoring can improve postoperative cognitive function(POCD) and reduce postoperative neurological complications, a prospective randomized controlled study method will be used in this study. 400 elderly patients undergoing shoulder arthroscopic surgery under general anesthesia combined with brachial plexus block will be selected. They will be randomly divided into control group and experimental group according to whether cerebral oxygen saturation monitoring was used during the operation. The control group maintain the target blood pressure only according to the controlled hypotension guideline, and the experimental group adjust the controlled hypotension level under the guidance of cerebral oxygen saturation monitoring. The general condition, operation, anesthesia and hospitalization related data of the patients will be recorded.
Patients undergoing elective shoulder arthroscopic surgery under general anesthesia combined with brachial plexus block;
ASA grade ≤ grade III;
Patients Can communicate normally, can cooperate and complete cognitive function test;
Patients volunteered and signed informed consent.
BMI < 18 or > 27 kg / m2;
Previous history of dementia, psychosis or other central nervous system diseases or mental diseases, such as cerebral infarction, stroke, Parkinson's disease, etc;
Patients taking sedatives or antidepressants;
Alcoholics or drug addicts;