Brief resume of the intended work:  

•Propofol is the most commonly used intravenous inducing agent internationally because of its rapid onset of action, smooth induction short duration of action, fewer side effects, and rapid recovery properties. It is also used for maintenance and sedation in the intensive care unit. The side effects of propofol include hypotension, apnea, pain on injection, and myoclonus. Pain on injection is a major problem as it causes discomfort to the patient and compromises the analgesia which is an important component of anaesthesia . Pain on injection of propofol incidence in adults ranges from 28% to 90%. Pain on propofol injection can be immediate or delayed after 10 second to 20 seconds. The pain is described as sharp, burning, or aching. Even though the pain mechanism remains unsure, several techniques have been tried to alleviate propofol pain. Altering the formulation of the drug, osmolality, pH of the drug, injection volume, temperature, speed of injection, choice of a vein and intravenous cannula size, speed of carrier intravenous fluid, buffering action of blood, and use of preemptive drugs to decrease pain.

•Ketamine which is N-methyl-D-aspartate (NMDA) receptor antagonist has also been recognized to reduce pain induced by propofol. Also, it acts peripherally to reduce pain.

•Lignocaine pretreatment is most commonly used to decrease propofol injection pain.Local  anaesthetic like intravenous lignocaine hydrochloride is a cation solution. When it gets exposed to lipids in propofol, it liberates protons and decreases the pH of the solution; the lower pH decreases the anions in propofol. Hence more amount of propofol enters into the lipid phase and will cause reduced pain on injection. Other drugs like Nafamostat, Ketorolac, Ephedrine, Metoclopramide, Thiopentone, and Opioids have been tried.

•The present study is aimed at comparing the analgesic effect between intravenous ketamine and lignocaine in alleviating propofol injection pain