Postoperative cognitive dysfunction (POCD)is a common well disorder of the central nervous system after surgery, mainly manifested by impaired memory, spirit, language ability or other aspects of brain function. POCD, which often occurs in elderly patients over 65 years, The recent phase is recommended to be changed to perioperative neurocognitive impairment ( PND), The PND is used to describe the cognitive function changes that occur before and within 1 year after surgery, Based on the time of disease onset, It can be divided into neurocognitive impairment existing before surgery, postoperative delusion (POD) occurring hours to days after surgery, neurocognitive recovery delay (DNR) within 30 days after surgery, and postoperative neurocognitive impairment occurring weeks to months after surgery (POND). With the acceleration of the aging process of Chinese social population, the frequency of surgical treatment for elderly inpatients has also increased, and the elderly patients have postoperative sleep disorders, and POCD is relatively common. Surgical patients after surgical trauma, the body inflammation, sympathetic excitation and endocrine disorders, make postoperative sleep structure or pattern change, often lead to postoperative sleep disorders (PSD) , the main performance for patients with postoperative complaint difficult to enter and maintain sleep, frequent nightmares, total sleep quantity and quality reduction, etc. PSD is not only the most common manifestation of postoperative brain dysfunction, but also an important risk factor for inducing postoperative fatigue, postoperative hyperalgesia, metabolic dysfunction, and cardiovascular and cerebrovascular diseases. Moreover, it is considered to promote the development of postoperative delusion. At present, the common mode of general anesthesia is still mainly opioids, and opioids are an important part of general anesthesia and perioperative analgesia. Perioperative use of opioids is not only associated with adverse effects such as postoperative nausea and vomiting, excessive sedation, and ileus, but also leads to the occurrence of postoperative hypoxemia, hyperalgesia and postoperative chronic pain, and cognitive impairment. Therefore, the Association of Accelerated Rehabilitation Surgery indicates that the use of a multimodal analgesic regimen during the perioperative period reduces pain and reduces opioid-related adverse effects, and that opioid-free anesthesia ( OFA) is used in clinical work. At present, most clinical studies of OFA focus on adults aged 18-65 or 18 years old, and few studies focus OFA solely on the elderly population to observe its application effect. Therefore, it is necessary to conduct clinical studies to observe postoperative recovery in elderly patients with different types of anesthetics, investigate the incidence and severity of POCD, and determine the efficacy and safety of each anesthetic agent.
