Ketamine in prevention of pain during propofol injection

Background: Propofol has the disadvantage of causing pain or discomfort on injection. The aim of the study was to assess the efficacy of ketamine pretreatment to alleviate the propofol injection pain. Methods: One hundred ASA I and II adults, scheduled for various elective surgical procedures under Genral anaesthesia were included in the study. The patients were randomly divided into two groups to receive 2ml of pretreatment ketamine solution (0.2mg.kg1) or 0.9% saline intravenously. The venous drainage was occluded manually at mid arm. One fourth of the total calculated induction dose of propofol was administered over a period of 5 seconds. The patients were asked about the pain on injection. The verbal response and the behavioral signs, such as facial grimacing, arm withdrawal or tears were noted. A score of 0-3 which corresponds to no, mild, moderate and severe pain was recorded. Results: Pain was reduced significantly in the ketamine group (p 0.001) with no significant side-effects. Conclusions: We concluded that pretreatment with intravenous 0.2 mg kg-1 ketamine was effective in relieving propofol injection pain.