The inspired concentration of sevoflurane was adjusted to maintain BIS values < 60 and stable haemodynamics (systolic arterial pressure (SAP) > 80 mmHg and heart rate (HR) > 45 beats/min). Also, it was titrated to prevent signs of inadequate anesthesia (sweating, facial flushing, movement and swallowing, HR > 90 beats/min without evidence of hypovolemia, and a 15 mmHg increase in SAP, compared with baseline SAP). Fentanyl 1 μg/kg was given if needed to resolve of signs of inadequate anesthesia.