Pain on injection of propofol

A controlled randomized double-blinded clinical study was undertaken to evaluate and compare the efficacy of three methods of preventing pain during injection of propofol on induction of anesthesia. Patients were randomly allocated to six groups: saline pretreatment, followed by induction with propofol at room temperature plus saline; lidocaine pretreatment, followed by induction with propofol at room temperature plus saline; saline pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus saline; lidocaine pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus saline; saline pretreatment, followed by induction with propofol at room temperature plus lidocaine 40 mg; saline pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus lidocaine 40 mg. Pretreatment with lidocaine reduced the incidence of pain and discomfort significantly compared with unpretreated groups. Groups which received propofol mixed with lidocaine also showed a significant reduced incidence of pain. induction with cold 4 degrees C propofol showed no significant difference in reduction of injection pain.