Anaesthesia for operation No premedication will be prescribed. Patients will be induced with fentanyl 1 to1.5µg/kg, thiopentone 2-4mg/kg or propofol 2-3mg/kg and rocuronium 1mg/kg. Anaesthesia will be maintained with cisatracurium and isoflurane with air and oxygen. Intravenous morphine will be used for pain relief intraoperatively.