ABSTRACT: The animal models used in this study were Plexus anesthesia in frogs, Infiltration anesthesia in guinea pigs, Surface anesthesia in rabbits. The drugs were diluted with normal saline. Lignocaine2%: xylocaine hydrochloride injection IP, Bupivacaine 0.5%: Bupivacaine hydrochloride injections IP were prepared. Plexus anesthesia: Frog was pithed and spinal cord was destroyed up to the 3 vertebra. The abdominal pouch was filled with local anesthetic solution. Reflex activity was tested by immersing both feet of the frog every two minutes for not longer than 10 seconds into N/10 Hydrochloric acid. The time was noted. Surface anesthesia: Albino rabbits of either sex weighing 2.5 – 3.0kg ware selected. The conjunctival sac of one eye was held open, thus formed a pouch. 0.5ml of solution of the anesthetic was applied into the conjunctival sac for 30 sec.Infiltration anesthesia: Preparation of guinea pig: Guinea pigs (either sex) weighing 250-300grams were used. Lignocaine produced rapid onset of plexus anesthesia in Frogs in comparison to the bupivacaine at concentration of 0.1% & 0.2% which is statistically significant. Bupivacaine is more potent than the lignocaine as a surface anesthetic agent in the Rabbit, where as lignocaine could produce surface anesthesia at concentration of 0.5% or 0.1% or both. Both bupivacaine and lignocaine produced infiltration anesthesia on intradermal injection in guinea pigs but the duration of infiltration anesthesia produced by bupivacaine is more prolonged which is statistically significant in comparison to the lignocaine at all the three concentrations tested i.e. 0.05%, 0.1% & 0.2%.
Keywords: Local anesthesia, Lignocaine, Bupivacaine, Surface, Infiltration anesthesia