ECG, main arterial pressure (MAP), heart rate, oxygen saturation of peripheral haemoglobin (SpO2), pressure of end-tidal carbon dioxide was monitored continuously and registered at 5 min intervals during anaesthesia. Each group received propofol for anaesthesia induction. In group A and B anaesthesia was maintained with sevoflurane, in groups C and D with propofol. In groups B and D the depth of anaesthesia (BIS® Quatro Brain Monitoring Sensor, Covidien) and the neuromuscular blocking status (Infinity®, Trident® NMT SmartPod®, Dräger Medical) were monitored too. BIS and TOF values were recorded at 5 min intervals.