[Injection pain secondary to propofol-MCT/LCT and propofol-LCT--comparison of prophylaxis with lidocaine].
OBJECTIVE
Pain on injection is one of the most described side-effects of the intravenous application of propofol. This study was designed to assess the efficacy of lidocaine 40 mg in preventing incidence and severity of injection pain for two different propofol solvents.


METHODS
In a double-blind and prospective study 202 patients were enrolled and randomized to 4 different groups: group A receiving 2 ml NaCl 0.9 % and propofol-LCT (Disoprivan; AstraZeneca), group B 40 mg lidocaine and propofol-LCT, group C received 2 ml NaCl 0.9 % and propofol-MCT/LCT (Propofol-Lipuro, B. Braun Melsungen AG) and group D 40 mg lidocaine and propofol-MCT/LCT. According to the protocol, all patients were cannulated with a 18-G venous cannula at the dorsum of the hand and no other medicament was injected before the study drug. Time interval between test agents and propofol application in a dosage of 2 mg/kg was one minute. Severity of pain was evaluated during propofol injection over 30 seconds until loss of consciousness using a 4-point rating scale.


RESULTS
The incidence of injection pain did not differ between propofol-LCT and propofol-MCT/LCT (64 % and 53 %). Propofol-MCT/LCT significantly reduced the severity of pain compared to propofol-LCT (p < 0.05). The application of lidocaine resulted in a significant reduction in incidence (Propofol-MCT/LCT: 16 %; Propofol-LCT: 31 %) and severity of injection pain compared to placebo.


CONCLUSIONS
Propofol-MCT/LCT showed a significant advantage compared to propofol-LCT considering the severity of injection pain, but not in reducing the incidence of pain. The use of lidocaine resulted in a significant reduction of incidence and severity of injection pain for both propofol solvents.