A Comparison of Ondansetron and Lidocaine in Reducing Injection Pain of Propofol: A Randomized Controlled Study

Abstract Background Propofol injection pain is common. Previous studies found that ondansetron can also block sodium channels. Objective The primary outcome was the efficacy of ondansetron compared to lidocaine and placebo for the reduction of propofol injection pain. Method This trial was conducted in 240 patients, American Society of Anesthesiologists classification I-III and aged between 18-65 years old, undergoing elective surgery, and having a 20-gauge intravenous catheter at the hand dorsum. Each group of 80 patients received 8 mg of ondansetron in the O Group, 40 mg of lidocaine in the L Group and normal saline in the C Group. The study medications were blindly given then 1 minute later, the propofol was administered via the syringe pump at the rate of 600 ml/hr. for 30 seconds. Thereafter, the syringe pump of propofol was temporarily paused, and the patients were asked to rate his/her pain. Result The incidence of pain was lowest in the L group (66.2%) compared with the O (82.5%) and the C groups (85.0%) (P<0.01). The median pain score in the L, O, and C groups were 2 (0-4), 4 (2-5), and 4.5 (2-6), respectively (P<0.01). The incidences of no pain, mild, moderate, and severe pain were also significantly different in the L group (33.8%, 37.5%, 21.2%, and 7.5%, respectively) compared with those in the O group (17.5%, 31.2%, 31.2%, and 20.0%, respectively) and the C groups (15.0%, 22.5%, 40.0%, and 22.5%, respectively) (P<0.01).. Conclusion Pretreatment with intravenous lidocaine, rather than ondansetron, can reduce the incidence and intensity of propofol-induced pain.