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

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.