Anesthesia management
bradycardia, postoperative nausea and vomiting, hypotension
NEUROMUSCULAR BLOCKADE
All patients received routine preoperative preparation with no premedication. Standard intraoperative monitoring, including five lead electrocardiography, pulse oximetry, non-invasive blood pressure, bispectral index, and transcutaneous carbon dioxide (Sentec®, SenTec AG, Terwill, Switzerland), was applied to all patients. Pre-oxygenation was performed via a facemask using pure oxygen at a flow of 10 L/min until fractional expired oxygen ≥ 90%. Anesthesia induction consisted of intravenous target-controlled infusion of propofol at an effect-site concentration of 4 μg/ml and remifentanil at 5.0 ng/ml, and intravenous bolus of fentanyl 1 μg/kg for analgesia, succinylcholine 2 mg/kg for neuromuscular blockade. For anesthesia maintenance, the propofol target was adjusted to maintain BIS between 40 and 50, and the remifentanil target was adjusted to maintain mean arterial pressure (MAP) ranging between 80 and 120% of the preoperative MAP. Additional 0.5 mg/kg of succinylcholine was added every five minutes until the end of surgery. Intravenous ephedrine 6 mg was given to rescue hypotension (MAP < 65 mmHg), and intravenous atropine 0.5 mg was given to rescue bradycardia (heart rate, HR < 60 bpm). Palonosetron 0.25 mg and dexamethasone 5 mg were given intravenously to prevent postoperative nausea and vomiting.Patients were intubated with an ID 6 mm reinforced endotracheal tube using a video laryngoscope in the MV + ETT group. Patients were ventilated under volume-controlled ventilation mode, tidal volume of 8 ml/kg, respiratory rate of 12 bpm, the inspiration-expiration ratio of 1:2, oxygen concentration of 50%, oxygen flow of 2 L/min. Ventilator parameters were adjusted to maintain the end-tidal carbon dioxide pressure (PDuring the intraoperative period, the heart rate (HR), MAP, peripheral arterial oxygen saturation (SpO