Comparison of efficacy of ketamine and dexmedetomidine for prevention of pain due to propofol injection

Abstract

Background: Propofol is a popular intravenous anesthetic induction agent which produces a smooth, rapid induction with rapid clearance and recovery but Pain on injection with Propofol is a common problem and can be very distressing to the patient. Ketamine is a phencyclidine derivative routinely used as an inducing agent and Dexmedetomidine Hydrochloride, an imidazole compound is the alpha 2 agonist. The present study was undertaken to compare the efficacy of Ketamine (0.5 mg/kg) and Dexmedetomidine (0.5 mcg/kg) in preventing the incidence and reducing the severity of pain on Propofol injection.Method: 150 patients, ASA I&II, 18-60 year old undergoing elective surgical procedure under general anaesthesia (GA) were randomly assigned into 3 equal groups. Group C, Group K and Group D. In Group C 10 ml Normal Saline, In Group K Ketamine 0.5 mg/kg diluted to 10 ml with normal saline and in Group D Dexmedetomidine 0.5 mcg/kg diluted to 10 ml with normal saline was infused over 10 minutes before injecting Propofol. All study medications were prepared in a 10ML syringe that was covered with black tape by an anaesthesiologist who was not involved in the study. HR,BP,SPO2and Pain Scores were noted at baseline, after premedication, while injecting study drugs at 3, 5 and 10 minutes and while injecting Propofol at the beginning, after half Propofol was injected, after complete Propofol was injected and at 1,3 and 5 minutes after completing the Propofol. Incidence and severity of pain and involuntary movements, verbal communication by the patient was watched constantly. Injection pain was graded using a 4-point scale. The pain score was evaluated as ‘0’ when there was no discomfort in the injection area (no pain), ‘1’ when the patient simply answered