Stephen Shei-Dei Yang1, Shang-Jen Chang. 1. Division of Urology, Buddhist Tzu Chi General Hospital, Taipei and Medical College of Buddhist Tzu Chi University, Hualien, Taiwan.
Abstract
PURPOSE: We report the effects of bladder over distention on pediatric voiding function. MATERIALS AND METHODS: We enrolled healthy kindergarten children (mean age 4.5 +/- 1.0 years) for 2 observations of uroflowmetry and post-void residual urine. Additional observations were requested if the voided volume was less than 50% of expected bladder capacity. Post-void residual was assessed within 5 minutes after voiding. A post-void residual of more than 20 ml is regarded as increased. Bladder capacity is defined as voided volume plus post-void residual and shown as percentage of expected bladder capacity. The uroflowmetry curves were categorized as bell-shaped or nonbell-shaped. RESULTS: Among 188 children 355 observations of uroflowmetry and post-void residual were eligible for evaluation. Nonbell-shaped uroflowmetry curves and increased post-void residual were noted in 75 (21.1%) and 78 (22%) of 355 voids, respectively. Based on the receiver operating characteristic curve for the nonbell-shaped curves and increased post-void residual, bladder capacity of 115% of expected bladder capacity or more is defined as bladder over distention. There were statistically more increased post-void residuals and more nonbell-shaped uroflowmetry curves in the voids with bladder over distention than in those without over distention (p <0.01). Of the 38 children displaying both types of curves the nonbell-shaped curves usually occurred at a higher bladder capacity than did the bell-shaped curves (133% +/- 46% expected bladder capacity vs 84% +/- 38% expected bladder capacity, p <0.01). Peak uroflow rate increased as bladder capacity increased but decreased at extreme bladder over distention. CONCLUSIONS: Optimal bladder capacity is important for assessing pediatric voiding function. Bladder over distention resulted in more nonbell-shaped uroflowmetry curves and more increased post-void residual. At extreme over distention peak flow rate decreased as well.
PURPOSE: We report the effects of bladder over distention on pediatric voiding function. MATERIALS AND METHODS: We enrolled healthy kindergarten children (mean age 4.5 +/- 1.0 years) for 2 observations of uroflowmetry and post-void residual urine. Additional observations were requested if the voided volume was less than 50% of expected bladder capacity. Post-void residual was assessed within 5 minutes after voiding. A post-void residual of more than 20 ml is regarded as increased. Bladder capacity is defined as voided volume plus post-void residual and shown as percentage of expected bladder capacity. The uroflowmetry curves were categorized as bell-shaped or nonbell-shaped. RESULTS: Among 188 children 355 observations of uroflowmetry and post-void residual were eligible for evaluation. Nonbell-shaped uroflowmetry curves and increased post-void residual were noted in 75 (21.1%) and 78 (22%) of 355 voids, respectively. Based on the receiver operating characteristic curve for the nonbell-shaped curves and increased post-void residual, bladder capacity of 115% of expected bladder capacity or more is defined as bladder over distention. There were statistically more increased post-void residuals and more nonbell-shaped uroflowmetry curves in the voids with bladder over distention than in those without over distention (p <0.01). Of the 38 children displaying both types of curves the nonbell-shaped curves usually occurred at a higher bladder capacity than did the bell-shaped curves (133% +/- 46% expected bladder capacity vs 84% +/- 38% expected bladder capacity, p <0.01). Peak uroflow rate increased as bladder capacity increased but decreased at extreme bladder over distention. CONCLUSIONS: Optimal bladder capacity is important for assessing pediatric voiding function. Bladder over distention resulted in more nonbell-shaped uroflowmetry curves and more increased post-void residual. At extreme over distention peak flow rate decreased as well.