After sufficient oxygenation and nitrogen removal, the two groups received the same scheme of intravenous inhalation combined with endotracheal intubation general anesthesia: propofol 50–80 μg·kg-1·min-1 and remifentanil 0.05–0.15 μg·kg-1·min-1 intravenous pumping, and sevoflurane 1–2% inhalation maintenance. According to the administration time and muscle relaxation in the operation area, 0.1 mg/kg atracurium CIS sulfonate and 5 μg sufentanil were added intermittently to maintain a bispectral index (BIS) value of 45–60, and the fluctuations of blood pressure (BP) and heart rate (HR) were within 20% of the baseline value. Both groups were given 5 mg of tropisetron intravenously after the operation. After surgery, the participants were transferred to the post-anesthesia care unit (PACU), where they achieved complete anesthesia recovery before transfer to the surgical ward.
Collectible 200 mg was given orally every 12 h. After tracheal extubation, PCIA was administered 48 h after surgery. The PCIA formulae were sufentanil 100 μg and tropisetron 10 mg, diluted to 100 mL with 0.9% normal saline; the background dose was 1 mL/h, the controlled additional dose (PCA) was 2 mL, and the locking time was 10 min. In addition, parecoxib sodium 40 mg was injected intravenously into patients with a numeric rating scale (NRS) score of ≥5. Patients who developed undesirable opioid side effects (nausea and vomiting) were given tropisetron 5 mg intravenously every 6 h.