Meta-analysis: does lidocaine gel before flexible cystoscopy provide pain relief?

OBJECTIVE: To consolidate previous reports and conduct a meta-analysis to draw further conclusions on the efficacy of the instillation of lidocaine gel before flexible cystoscopy, as it has had varying efficacy in several randomized controlled studies.
METHODS: We reviewed previous reports cited in PubMed, Biosis and the Cochrane Library, identified by a professional librarian searching for English language-only randomized controlled studies involving the keywords, lidocaine, cystoscopy, gel and pain, yielding 14 studies. Ten studies were excluded as they provided no comparison with appropriate control groups or contained insufficient data for analysis. Attempts to contact the authors of these studies yielded no additional data. A meta-analysis was conducted using a random-effects model.
RESULTS: Four studies were included in the analysis, two double-blind and two single-blind, totalling 411 male patients. Three of the studies found no statistical improvement and one study found a statistically significant improvement in pain relief using lidocaine gel. Studies varied on the quantity of gel instilled and on the dwell time of gel before cystoscopy. The meta-analysis found that subjects who received anaesthetic-impregnated gel were 1.7 times more likely not to experience moderate to severe pain (<2, 3 or 30, based on the scale used; odds ratio 1.7, 95% confidence interval 1.1-2.8) than subjects who did not have intraurethral instillation of gel.
CONCLUSIONS: These data suggest that intraurethral instillation of lidocaine gel vs plain lubricating gel reduces the likelihood of moderate to severe pain during flexible cystoscopy.