Perioperative management
PONV
The electrocardiogram (ECG), pulse oxygen saturation, and bispectral index (BIS) were monitored once the patient entered the operating room. Depending on the patient’s condition, invasive or noninvasive arterial blood pressure monitoring was performed. Intravenous (IV) sufentanil (0.3 µg/kg), etomidate (0.2–0.3 mg/kg), and atracurium (0.6 mg/kg) were used to induce general anesthesia. Following intubation, sevoflurane (1.5-3%) was inhaled to maintain BIS values between 40 and 60. Intermittent atracurium injections kept muscles relaxed, and the continuous infusion volume of remifentanil (0.1–0.2 µg/(kg·min)) was adjusted to maintain the heart rate (HR) and the mean arterial blood pressure (MAP) within 80–120% of baseline. When the MAP was less than 80% of the baseline value, IV ephedrine or IV phenylephrine was administered, and IV atropine was administered when the HR was less than 40 bpm. IV 5 mg dexamethasone were administered for PONV prevention. Flurbiprofen (100 mg) was injected intravenously 30 min before the end of the operation to ensure postoperative analgesia was achieved. When the patient was awake and the tidal volume was sufficient, the tracheal tube was removed. The anesthesiologist then transferred the patient to the postanesthesia care unit (PACU).