esketamine is an optical isomer of ketamine. Compared with ketamine, esketamine has the characteristics of higher effective value, stronger receptor affinity, less adverse reactions of nervous system, and pharmacokinetics is controllable.

Domestic and foreign studies have focused on the therapeutic effect of esketamine on major depression, but less attention has been paid to perioperative depression.This study intends to explore the effect of small doses of esketamine on patients with breast cancer.Postoperative depression and pain are observed.

This study intends to explore the effect of small doses of esketamine on patients with breast cancer.WE pay attention to :

1. Safety of low-dose single intravenous injection of esketamine (1)The influence of intraoperative vital signs of patients after medication, such as blood pressure and heart rate fluctuation; (2)the duration of recovery after anesthesia; (3)postoperative adverse reactions, such as nausea and vomiting, dizziness and diplopia, respiratory depression, laryngeal spasm, delirium agitation, etc

2. Effect of single intravenous injection of low-dose ketamine on postoperative depression in patients undergoing radical mastectomy (1) 1 day before surgery, 2 days, 5 days, 30 days, 90 days after surgery Hamilton Depression Scale scores; (2) The serum leptin level 1 day before surgery, 2 days after surgery and 5 days after surgery; (3) Correlation between depression scale score and leptin level

3. Effects of low dose esketamine on acute and chronic pain in patients undergoing radical mastectomy

   • visual analogue scale scores at 6, 12 and 24 hours after surgery;

     • visual analogue scale scores at 3, 5, 30 and 90 days after surgery;

       • the number of analgesic remedies

Inclusion Criteria:

• (1) Female patients who planned to undergo unilateral modified radical mastectomy in breast surgery; (2)Years of education ≥5 years,American Society of Anesthesiologists Ⅰ-II grade; (3) All patients undergoing surgery within 1 week after diagnosis of breast cancer, and do not receive preoperative radiotherapy or chemotherapy; (4) All the patients were married and had children, and were mainly cared for by their immediate family members after surgery.

Exclusion Criteria:

• (1) Antidepressant treatment was received within the last 2 months; (2) previous personality disorder, intellectual retardation, brain injury or brain disease, combined with schizophrenia, mania and other mental diseases; (3) Preoperative patients with hyperthyroidism or hypothyroidism, severe cardiovascular disease, diabetes, severe blood deficiency, and abnormal heart, lung, liver, and kidney functions; (4) with diseases of the immune system, or use drugs that have obvious effects on the immune system; (5) Pregnancy or lactation;

female

esketamine 10ml (5mg/ml) and normal saline 10ml were respectively set as drug A or drug B.

Without the knowledge of the experimenter, the predetermined dose of drug A or B will be given to the experimenter before induction of anesthesia, with 0.05 mL /kg for each patient.

After all samples are collected, the third party will announce the grouping and medication.