Prospective randomized crossover trial of lubricant gel against an anaesthetic gel for outpatient cystoscopy

Abstract

Objective. Flexible cystoscopy is routinely performed under local anaesthetic. The aim of this study was to compare the outcomes of using an anaesthetic gel and a non-anaesthetic gel in the same patient. Material and methods. Men undergoing 3-monthly check cystoscopies were recruited to this prospective, randomized, double-blind, crossover trial. Primary outcome measures were visual analogue scale scores for pain and the incidence of infection. A total of 51 men were randomized to receive 11 ml of either a non-anaesthetic gel or Instillagel® as a lubricant on their first visit; they then crossed over to the other agent on their next visit. A nurse who was blinded to the type of lubricant used recorded post-procedural visual analogue scale scores for pain and contacted the patients 48 h postoperatively to check the incidence of infection. Results. The median difference in pain score (non-anaesthetic minus anaesthetic) was 0 (range −5.3 to 7.5) and the mean difference 0.24 (SD 2.3), with no evidence of a ‘time period effect’ between instillations, i.e. the sequence of instillation with Instillagel followed by aqueous gel or aqueous gel followed by Instillagel in an individual did not have a significant effect. One patient had a urinary tract infection after using each type of gel. A non-inferiority test gave strong evidence that the mean difference in pain score was <1 (p=0.011). Conclusions. Our study suggests that the pain experienced with the non-anaesthetic gel is no greater than that experienced with the anaesthetic gel. The non-anaesthetic gel is as effective as the anaesthetic gel and its regular use should be advocated in routine practice.

• Cystoscopy
• anaesthetic gel
• lubricating gel
• bladder cancer