Anesthesia methods
breast cancer
MUSCLE RELAXATION, BREAST CANCER
All breast cancer patients were intubated with general anesthesia, routinely abstained from drinking for 6 h and from eating for 8 h before surgery. One vein was opened after the patient was admitted to the room. Before the start of the surgery, all patients were intravenously injected with 0.07 mg/kg midazolam, 0.2 mg/kg etomidate, 0.5 µg/kg sufentanil and 0.7 mg/kg rocuronium. After entering anesthesia, patients were maintained by sedation with 4–10 mg/(kg•h) propofol + 1% sevoflurane, analgesia with 0.05–0.25 µg/(kg•min) remifentanil, muscle relaxation with 0.3–0.6 mg/kg rocuronium maintenance, and muscle relaxants were stopped 35 min before the end of surgery. The target-controlled concentration of propofol, remifentanil and rocuronium was adjusted at any time during the operation according to the patient’s body movement response, the change of heart rhythm, and blood pressure until the end of the operation. Propofol and remifentanil were stopped at the end of the operation in all four groups, and 20 µg/kg neostigmine and 10 µg/kg atropine were administered to antagonize the residual effect of muscle relaxants. All patients were given 3 mg granisetron IV at the end of surgery and appropriate intraoperative fluid rehydration according to the situation, and the tracheal tube was removed after the patients had the conditions for extubation at the end of surgery.