After preoxygenation for 3 min, anesthesia was induced with fentanyl 1 - 3 µg/kg, propofol 1.5-2.5 mg/kg (to achieve an SE <50 and a difference<10 between RE and SE; RE-SE) and rocuronium 0.6 mg/kg. Tracheal intubation or slipping of laryngeal mask appropriate for body weight were used according to the discretion of the attending anaesthetist. Anaesthesia was maintained with a 0.6-1 minimum alveolar concentration of sevoflurane (MAC-Sevo) with air in 40% oxygen and fentanyl 1 µg/kg boluses to maintain SE <50 and RE-SE <10 and heart rate and mean arterial blood pressure within 20% of their baseline values. Rocuronium 0.1 mg/kg was given to maintain suppression of the second twitch using a train-of-four stimulation. The patients' lungs were ventilated to maintain an ETCO2 of 30-35 mmHg. Sevoflurane were discontinued at the start of skin closure, residual neuromuscular block was antagonized and the trachea extubated.