Randomized Controlled Trial to Assess the Impact of Intraurethral Lidocaine on Urodynamic Voiding Parameters

Objectives The aim of the study was to determine whether intraurethral anesthesia decreases voiding efficiency (VE; voided volume/(voided volume + residual volume)) and impacts other urodynamic parameters in healthy female volunteers during urodynamic studies. Methods This was a randomized double-blind placebo-controlled study of asymptomatic women aged 18 to 60 years. Subjects completed a visual analog scale and baseline questionnaires to assess pain and lower urinary tract symptoms, respectively. They performed an uninstrumented baseline uroflow, followed by physiologic filling to 250 mL or greater. Subjects were randomized to receive 5 mL of intraurethral aqueous gel or 2% lidocaine gel and then underwent a second uninstrumented uroflow. They then completed complex cystometry, urethral pressure profilometry, and pressure-flow studies. Results Twenty-three randomized subjects (12 placebo, 11 lidocaine) were included. Baseline uroflow VE was similar between the placebo and lidocaine groups. After study drug administration, VE was not different between groups (89.3 [85.9-93.9] vs 89.5 [82.5-91.7], P = 0.74). There were also no differences between groups in visual analog scale scores, sensation during cystometry, maximum urethral closure pressure, or micturition parameters (maximum detrusor pressure and detrusor pressure at maximum flow). The placebo group had a lower percentage of interrupted flow pattern (0% vs 36%, P = 0.02) and a lower rate of increased electromyographic activity during micturition (25% vs 73%, P = 0.02). Conclusions In this pilot study of 23 asymptomatic women, intraurethral administration of lidocaine did not decrease VE compared with placebo. The lidocaine group had a greater percentage of interrupted flow patterns and increased electromyographic activity during micturition.