50% dextrose versus normal saline as distension media during cystoscopy for assessment of ureteric patency

Objective To compare the visualization of ureteric jets when using 50% dextrose (D50) as opposed to normal saline (NS) as distension media during cystoscopy. Study design Cross sectional study. Methods Two patients each had two cystoscopy videos recorded at the time of a ureteric jet; one using NS and the other using D50 resulting in two sets of paired videos (four videos). A fifth cystoscopy video was recorded, as a control, at a time when there was no ureteric-jet. Fifty participants including attending physicians, residents and medical students were recruited at an academic-affiliated community hospital. Participants were blinded to the medium used and viewed each of the five videos. Participants assessed each video for presence of a ureteric-jet, ease of interpretation, and compared the paired D50 and NS videos for clarity of ureteric-jets. Main outcome measures Participant's assessment of clarity of the ureteric jets when D50 was used as compared to when NS was used in the paired videos. Results All 100 observations of the two D50 videos with jets identified the presence of a jet; for the NS videos, 96/100 observations identified a jet, 2/100 did not identify a jet and 2/100 were unsure. 48/50 observations of the video with no jet were correct, while 2/50 were unsure. Participants rated the ureteric-jets to be clearer in videos with D50 (86% vs 14%, P < 0.001); and had difficulty interpreting cystoscopy videos with NS (62% vs 2%, OR: 80, 95% CI: 10.2-627.6). Conclusion Participants preferred the clarity of the ureteric-jet when 50% dextrose was used as the distension medium during cystoscopy as compared to normal saline.