Lignocaine gel: does it cause urethral pain rather than prevent it?

Abstract

To test the hypothesis that the chemical content of lignocaine gel is the cause of urethral pain during its instillation into the urethra. A prospective, double blind study was designed to test whether plain aqueous gel caused less delivery discomfort in the male urethra than 2% lignocaine hydrochloride gel (Instillagel). 100 consecutive, consenting male patients attending for flexible cystoscopy were recruited and randomised to receive 11 ml of 2% lignocaine hydrochloride gel or 11 ml of plain aqueous gel. Upon receiving the gel into the urethra, the patient was asked to score any associated discomfort by using a horizontal, 100mm, non-graphical, visual analogue scale. Statistical comparison between the groups was made using the non-parametric Mann-Whitney U-test. Statistical analysis by Mann-Whitney U-test showed a significant reduction in urethral delivery discomfort in those patients receiving plain gel compared to those receiving 2% lignocaine hydrochloride gel (p=0.039). This current study has shown that plain aqueous gel causes significantly less delivery discomfort in the male urethra than 2% lignocaine hydrochloride gel (Instillagel).