A comparison of dexmedetomidine combined with propofol for conscious sedation during endoscopic retrograde cholangiopancreatography(ERCP)

This trial will compare the sedative medicine dexmedetomidine and propofol with propofol. The comparison will take place in a group of patients undergoing ERCP without intubations. Although TCI systems decrease the risk of respiratory during sedation with propofol in the patients undergoing ERCP, the risk persists. Propofol has some side effects including reduced breathing efforts, which sometimes requires the anaesthetist to intervene and support the airway or even convert the sedation to a general anesthesia with intubations. Dexmedetomidine as a newer sedative medicine, appears to have fewer of these effects and reduce the total amount of propofol. Patients will be randomized to receive either propofol or dexmedetomidine combined with propofol. They will receive their normal general anesthesia without intubations. The researchers will be measuring: the target concentration of propofol in maintain anesthesia and the total amount of propofol during the surgery; need for airway support; and haemodynamic values intraoperatively.