Effects of an intraoperative intravenous Bolus Dose of Dexmedetomidine on postoperative catheter-related bladder discomfort in male patients undergoing transurethral resection of bladder tumors: a randomized, double-blind, controlled trial

Purpose To investigate whether the effect of intravenous bolus doses of dexmedetomidine on postoperative catheter-related bladder discomfort (CRBD) was dose-dependent in male patients undergoing transurethral resection of bladder tumors (TURBT). Methods The study protocol was registered at the Chinese Clinical Trial Registry (ChiCTR 2,000,034,657, date of registration: July 14, 2020). Adult male patients were randomized to one of four groups: placebo (Group C); dexmedetomidine 0.2 µg/kg (Group D 0.2); dexmedetomidine 0.5 µg/kg (Group D 0.5); or dexmedetomidine 1 µg/kg (Group D 1). The primary outcome was the incidence of moderate-to-severe CRBD at 0, 1, 6, 24, and 48 h postoperatively. Results The incidence of moderate-to-severe CRBD was significantly lower in Group D 0.5 and Group D 1 than in Group C at 0 h (13% vs. 40%, P = 0.006; 8% vs. 40%, P = 0.001), 1 h (15% vs. 53%, P < 0.001; 13% vs. 53%, P < 0.001), and 6 h (10% vs. 32%, P = 0.025; 8% vs. 32%, P = 0.009) postoperatively. Compared with baseline, both the MAP and HR were significantly lower in Group D 1 at 1 min ([94 ± 15] vs. [104 ± 13] mm Hg, P = 0.003; [64 ± 13] vs. [73 ± 13] bpm, P = 0.001) and 30 min ([93 ± 10] vs. [104 ± 13] mm Hg, P < 0.001; [58 ± 9] vs. [73 ± 13] bpm, P < 0.001) postextubation. Conclusion The effect of intravenous bolus doses of dexmedetomidine on postoperative CRBD was dose-independent, whereas intravenous administration of 0.5 µg/kg dexmedetomidine reduced the early postoperative incidence of CRBD with minimal side effects. Trial registration Clinical trial number and registry URL: ChiCTR 2,000,034,657, http://www.chictr.org.cn , date of registration: July 14, 2020.