Alkalisation of lignocaine-adrenaline reduces the amount of pain during subcutaneous injection of local anaesthetic.

A double blind, randomised controlled trial was performed to compare the amount of pain experienced after subcutaneous infiltration of lignocaine with adrenaline, and the same anaesthetic buffered to pH 7.1-7.3, in patients undergoing liposuction (n = 8), blepharoplasty (n = 7), mammaplasty (n = 6), and in volunteers (n = 10). A linear analogue pain scale was used to access pain. In all four groups the buffered solution caused significantly less pain (p < 0.001 except for mammaplasty--p = 0.02).