Minimum effective dose of lidocaine on preventing propofol injection pain in children

Objective To investigate the minimum effective dose of lidocaine on preventing propofol injection pain in children. Methods One hundred children in 1-3 years old and 100 children in 3-7 years old who was given total intravenous anesthesia was selected, and they were divided into five groups, with 20 cases in each group. Each group was treated by lidocaine and propofol, lidocaine dosage in group A, B, C, D, E respectively was 0.1 mg/kg, 0.2 mg/kg, 0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg. Lidocaine on preventing propofol injection pain in two age children were recorded, the incidence and strength of propofol injection pain were evaluated. Methods In 1 to 3 years old, the incidence of propofol injection pain in group A, B, C, D, E respectively was 90%(18/20), 85%(17/20), 40%(8/20), 30%(6/20), 25%(5/20), which in group A, B was higher than that in group C, D, E, the differences were significant(P<0.05). In 3 to 7 years old, the incidence of propofol injection pain in group A, B, C, D, E respectively was 75%(15/20), 30%(6/20), 25%(5/20), 30%(6/20), 20%(4/20), which in group A was higher than that in group B, C, D, E, the differences were significant (P<0.05). Conclusions The minimum effective dose of lidocaine required to prevent injection pain due to propofol in 1 to 3 years is 0.3 mg/kg, which in 3 to 7 years is 0.2 mg/kg. Key words: Lidocaine; Propofol; Injection pain