Postoperative cognitive dysfunction (POCD) is one of the common complications of cancer patients after operation with a 8.9%-46.1% incidence, which severely affecting patients' postoperative recovery, increasing the medical cost, affecting the social function of patients, reducing the quality of life and increasing the mortality.

Surgical trauma and perioperative pain can induce systematic inflammatory response and release systematic inflammatory mediators, which can enter the central nervous system (CNS) and lead to CNS inflammatory. In order to prevent the development of POCD among elder patients, the discovery of effective interventions reducing perioperative pain and inflammatory response is important.

Transcutaneous Electrical Acupoint Stimulation (TEAS) is a non-invasive alternative to needle-based electro-acupuncture (EA). It combines the acupuncture and transcutaneous electrical nerve stimulation (TENS) by pasting the electrode piece on the acupoint instead of sticking the needles on the skin. TEAS can trigger the release of endogenous neurotransmitters, releasing endogenous analgesic substances, such as endorphins. TEAS also can reduce the intraoperative anesthetic consumption, postoperative pain score, postoperative nausea and vomiting (PONV), and improve the postoperative recovery of patients. Recently, TEAS was found to improve the cognitive function of geriatric patients with silent lacunar infarction. However, the current TEAS mainly focus on intraoperative. The effect of perioperative TEAS on POCD is not clear.

Here, the effect of TEAS on POCD in geriatric adults undergoing radical resection of gastrointestinal tumors under general anesthesia was investigated to determine whether TEAS can decrease perioperative pain or inflammatory response to prevent the occurrence of POCD and to find out the relationship among perioperative TEAS, inflammatory response, postoperative pain, and POCD preliminarily.

This study aims to evaluate the effect of perioperative transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive dysfunction (POCD) in elderly patients who were diagnosed with gastrointestinal tumor and received radical resection of gastrointestinal tumors under general anesthesia and to determine the relationship among perioperative TEAS, inflammatory response, postoperative pain, and POCD preliminarily.

Inclusion Criteria:

1. Patients aged 60 years or older;
2. Patients were diagnosed with gastrointestinal tumor and received radical; resection of gastrointestinal tumors under general anesthesia in Subei people's hospital of Jiangsu province;
3. The patients understood the research content and signed the informed consent form;
4. American Society of Anesthesiology (ASA) score I-III;
5. No frailty before operation;
6. D-dimer was normal before the operation

Exclusion Criteria:

1. Patients with cognitive dysfunction before the operation or patients with previous history of cognitive dysfunction, dementia and delirium;
2. Patients with a history of severe depression, schizophrenia and other mental and nervous system diseases or taking antipsychotic or antidepressant drugs in the past;
3. Patients with severe hearing or visual impairment due to eye or ear diseases without assistive tools;
4. Patients who are unable to communicate or have difficulty communicating;
5. According to the definition of "China chronic disease and its risk factors monitoring report (2010)" (male average daily pure alcohol intake ≥ 61g, female average daily pure alcohol intake ≥ 41g, alcohol volume (g) = alcohol consumption (ML) × alcohol content% × 0.8);
6. Patients who were hospitalized for three months or more before surgery or who had received surgical treatment within three months;
7. Patients who can't take care of themselves or are physically disabled and unable to carry out nerve function test;
8. Patients with severe heart, liver and renal failure;
9. Patients with hypoxemia (blood oxygen saturation < 94%) more than 10 minutes during operation;
10. Patients admitted to ICU after operation;
11. Patients who quit or died due to noncooperation or sudden situation;
12. Patients who already participate in other clinical studies which may influence this study;
13. Patient who underwent emergency surgery;
14. Patient had a history of recent or conventional acupuncture treatment.

Underlie results in a publication

starting in October 2020

Study which was used to do meta analyse

Patient don't konw which group they are in because we all told them that they will feel nothing during the intervention.

The outcomes assessor just to evaluate indicators, they don't know the specific content of the patient's experiment