Standard general anesthesia management
postoperative nausea and vomiting
MUSCLE RELAXATION, POSITIVE
All patients received a standardized general anesthetic technique. Anesthesia was induced with IV midazolam 0.03 mg/kg, propofol 1.5–2 mg/kg and sufentanil 0.2 μg/kg. Rocuronium 0.6 mg/kg was given to facilitate supreme laryngeal mask insertion. Maintenance of anesthesia was performed with continuous infusion of propofol, target-controlled infusion of remifentanil 2–3 ng/ml, and an intermittent supplemental sufentanil bolus of 0.1 μg/kg, titrated to keep mean blood pressure within 20% of the baseline values, and bispectral index (BIS) values between 40 and 60. Positive pressure ventilation was controlled to maintain an end-tidal carbon dioxide partial pressure between 35 and 55 mmHg. All patients received tropisetron 5 mg IV 30 min before the end of surgery for postoperative nausea and vomiting prophylaxis. At the end of surgery, muscle relaxation was reversed with neostigmine and atropine. Patients were extubated and transferred to the post-anesthesia care unit (PACU) for observation.