Reducing the pain of intradermal lignocaine injection by pH buffering

The effect of pH on the pain of administration and efficacy of 1% lignocaine was investigated in a prospective, double-blind, randomized study of 20 adult volunteers. Onset and spread of anaesthesia by intra-dermal injection were not altered, but there was a significant reduction in pain scores with a higher pH. Overall, pain scores appear to be more dependent on the speed of injection rather than alteration of pH.