Furosemide Use and Time to Confirmation of Ureteral Patency During Intraoperative Cystoscopy A Randomized Controlled Trial

OBJECTIVE: To investigate the effect of intravenous administration of furosemide on the time to confirmation for ureteral patency during intraoperative cystoscopy. METHODS: In a double-blind randomized controlled trial, intravenous administration of furosemide 10 mg was compared with placebo (normal saline) to investigate the effect of furosemide on the time to confirmation for ureteral patency during intraoperative cystoscopy. The primary outcome was time to confirmation of ureteral patency. Secondary outcomes included adverse reaction to study medication and delayed diagnosis of ureteric injury. A sample size of 72 per group (N=144) was powered to detect a 3-minute difference in time to confirmation of ureteral patency between groups. RESULTS: From May 2017 to March 2018, 215 patients were eligible for inclusion and 150 were randomized, with 145 available for final evaluation. The two groups were similar in regard to baseline characteristics. The administration of intravenous furosemide 10 mg in a routine cystoscopy resulted in a shorter time to confirmation compared with the administration of the placebo (86.5 seconds, interquartile range 55.0-137.0 vs 165.0 seconds, interquartile range 77.0-280.0; P<.05). Furthermore, at any given time period, patients receiving intravenous administration of furosemide 10 mg were 2.3 times more likely to have ureteral patency confirmed compared with patients receiving normal saline (95% CI 1.59-3.23). There were no adverse events related to administration of intravenous furosemide and no delayed diagnoses of ureteric injury. CONCLUSION: Compared with placebo, intravenous administration of 10 mg furosemide at time of intraoperative cystoscopy resulted in a statistically significantly shorter time to confirmation of ureteral patency, though the clinical significance of this finding is small.