Heart rate and mean arterial blood pressure were recorded before (baseline) and 10 min after the start of infusion; every 30 min during surgery; every 15 min during the stay in post anaesthesia care unit (PACU), and 8 hourly for the following 48 hours. MAC-Sevo was recorded every 15 min after intubation until the end of surgery. Intraoperative fentanyl consumption was recorded.