Premixing lidocaine reduces the incidence and severity of pain on injection of propofol

: The purpose of this study was to confirm the effect of premixed lidocaine for the reduction of pain during injection of propofol in adult patients. We conducted a prospective, randomized, double-blind trial on 106 patients. In the study group (n = 54), lidocaine 40 mg (2 ml of lidocaine 2%) was added to 180 mg of propofol (18 ml). In the control group (n = 52), 2 ml of normal saline was added to 180 mg of propofol. The pain on injection was rated as none, mild, moderate, or severe. Eleven patients (20.4%) in the study group experienced pain compared with 25 (48.1%) in the control group. Thirteen in the control group complained moderate or severe pain compared with only one in the study group. In conclusion, lidocaine 40 mg premixed with 180 mg propofol significantly reduces the incidence and severity of pain associated with propofol injection.