Effectiveness of lidocaine pretreatment to pain following propofol injection : A randomized, double-blind study

Background: Propofol is widely used as an intravenous anesthetic induction agent. However, pain on injection is a major disadvantage with reported incidence of approximately 70%. The objectives of the study were to compare effect of 0.9% normal saline 2 mL pretreatment for propofol-LCT on the incidence and severity of pain on injection versus 2% lidocaine 2 mL (40 mg) IV pretreatment injected. Materials and method: double-blind randomized controlled trial was conducted. One hundred and fourty ASA physical status I - III patients undergoing elective surgery were blinded and equally allocated into 2 groups. Patients in control group received 0.9% normal saline 2 ml and group lidocaine received 2% lidocaine 2 ml for pretreatment. Pain at the time of 30 mg propofol injection was assessed by blinded anesthesiologist on Numerical Rating Score (NRS) ranging from 0-10. Results: There were no significant differences between the two study groups regardless to sex, weight, ASA physical status classification, size of intravenous catheter, propofol induction dose and duration of anesthesia. The incidences of pain on propofol injection in control group and lidocaine group were 52.86% and 24.29% respectively (P=0.001). After injection, pain score in lidocaine group was significantly lower than control group (mean NRS,0.94+1.98 and 3.19+3.87, respectively;