Sedation during voiding cystourethrography: Comparison of the efficacy and safety of using oral midazolam and continuous flow nitrous oxide

Purpose: We compare the efficacy and safety profile of oral midazolam and continuous flow 50% nitrous oxide (N₂O) for alleviating anxiety and pain during voiding cystourethrography (VCU) in children. Materials and Methods: This prospective, randomized clinical trial study was conducted in the radiology unit of a tertiary care center. Children older than 3 years scheduled for VCU were given either 0.5 mg/kg midazolam orally or continuous flow 50% N₂O. Main outcomes were degree of anxiety and pain as assessed by the attending nurse and radiologist performing the test using a behavioral anxiety score, a distress score and an overall satisfaction score, side effects and recovery profile. Results: The study included 47 children (89% girls) with a mean age of 6 years (range 3 to 15). There were 24 subjects in the midazolam group and 23 in the N₂O group. Midazolam and N₂O provided adequate anxiety and pain relief to perform the examination, yet children given N₂O required less restraining and experienced a significantly shorter recovery time (29 ± 10 vs 63 ± 25 minutes, p < 0.001). Conclusions: Continuous flow 50% nitrous oxide and oral midazolam are comparably safe and effective in reducing anxiety and distress during VCU in children older than 3 years. However, N₂O provides a more rapid onset of sedating effect and has a shorter recovery time.