For anesthesia maintenance, TCI-remifentanil (fixed Cp of 20 ng/ml) and TCI-propofol (variable Ce < 2.0 µg/ml) for maintaining BIS 40-60 in Group R [14], and TCI-sufentnail (Cp of 0.4-0.8 ng/ml) and sevoflurane (< 1.5 MAC) for maintaining 80-120 % of preoperative value and BIS < 60 in Group C, respectively. Rocuronium is continuously infused (3 µg/kg/min) in both groups.