Comparison of pain on injection of newer formulation propofol and standard propofol with added lignocaine: A randomised double-blind prospective study

Background: The aim of the present prospective randomised double-blind clinical study was to compare the incidence of pain-free injection following the use of this new formulation (propofol with medium-chain triglycerides [MCT] and long-chain triglycerides [LCT]) with propofol dissolved in LCT with added 2% lignocaine in patients undergoing various surgical procedures under general anaesthesia. Methods: Sixty adult patients (age range 18–50 years) were randomised to receive either 20 mL propofol dissolved in a mixture of MCT–LCT [Group L (n = 30)] or 18 mL propofol dissolved in LCT with added 2 mL 2% lignocaine [Group S (n = 30)]. A specially trained clinical research investigator assessed the occurrence of injection pain using a four-graded pain scale. Results: There was no significant difference in propofol injection pain among patients who received either LCT propofol with added lidocaine, (Group S) (33.3%) or new formulation propofol (Group L) (30.0%) (P = 0.993). Conclusions: The newer formulation, MCT–LCT propofol, is equally effective vis-a-vis the conventional propofol with added lignocaine to reduce the incidence of pain, thereby eliminating the need for addition of another drug, lignocaine.