Low dose ketamine pretreatment for alleviation of propofol injection pain- A study

Abstract

Introduction: One of the most important disadvantages of propofol injection is intense burning pain. The present study was conducted with the aim to assess the effect of low dose Ketamine (100 µg/kg) in the alleviation of pain on propofol injection. Materials and Methods: Patients who underwent surgical procedures under general anaesthesia were allocated into two groups viz. Group K (n=35) -pre-treatment with ketamine 100µg/kg (1ml) and Group S (n=35)-pre-treatment with 0.9% normal saline (1ml) in this double-blinded, randomized study. After venous occlusion, ketamine was injected over 10 seconds, after which the occlusion was removed and over 20 seconds, the first 25% of the calculated dose of propofol was injected. The evaluation of the severity of pain was done by the verbal rating scale (VRS) during the injection of the induction agent for every 5 seconds and graded as 0 to 3.The data were recorded and analysedusing unpaired't' test and chi-square test as and where appropriate. Results:The demographic profiles were comparable between the two groups. It was observed that 42.9% of patients in normal saline and 80% in ketamine groups experienced no pain (p<0.05) while 31.4% and 17.1% of patients in normal saline and in ketamine groups respectively felt mild pain. No significant haemodynamic changes were observed in both the groups (p>0.05). Conclusion: It may be concluded that pre-treatment with low dose ketamine with a tourniquet just before propofol injection, significantly reduced the incidence and degree of propofol induced pain without significant adverse hemodynamic effects.