Delayed versus immediate urethral catheterization following instillation of local anaesthetic gel in men: a randomized, controlled clinical trial.

INTRODUCTION: The product information for local anaesthetic (lignocaine) gel recommends a delay of 'several minutes' between gel instillation and urethral catheterization in men. However, pilot data indicate that approximately half of physicians omit this delay. We aimed to compare the discomfort of urethral catheterization performed immediately or after a 2 min delay following instillation of local anaesthetic gel.

METHODS: We undertook a randomized, controlled, single-blinded, clinical trial in four large ED. A convenience sample of men requiring urethral catheterization for urinary retention or output monitoring was enrolled. Participants were randomized to catheterization either immediately (no delay group) or after a 2 min delay (2 min delay group) following the instillation of local anaesthetic gel. The pain score of catheterization was recorded immediately following the catheterization, using a 100 mm visual analogue scale.

RESULTS: Seventy-three patients were enrolled. There were 36 and 37 patients randomized to the no delay and 2 min delay groups, respectively. There was no significant difference between the two groups in mean patient age (71.5 +/- 15.1 vs 69.2 +/- 15.2 years, respectively, P = 0.53) or in the indication for catheterization (retention 29 vs 27, respectively, P = 0.62). There was no statistically significant difference in pain scores between the two groups. The median (interquartile range) pain scores were 22.2 (23.4) and 27.8 (35.3) for the no delay and the 2 min delay groups, respectively (P = 0.47).

CONCLUSION: A 2 min delay following instillation of local anaesthetic gel before urethral catheterization in men does not decrease the pain of the procedure.