A controlled trial of pain on skin infiltration with local anaesthetics

A double-blind, randomised controlled trial was performed to compare the pain experienced on intradermal and subcutaneous injection of lignocaine 1% with adrenaline 1:100,000, lignocaine 1%, procaine 1% and normal saline. A linear analogue pain scale was used to assess pain. Lignocaine with adrenaline caused the most pain and was more painful than lignocaine 1%, which in turn was more painful than procaine or normal saline. These differences were significant at p less than 0.05 or greater for all comparisons except procaine 1% and normal saline. In conclusion, procaine 1% appears to be the local anaesthetic of choice from among those tested for intradermal and subcutaneous injection.