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
