| Background and objectiveUrinary flow rate is defined as the urine volume voided through urethra in a given time, described by ml/s. Uroflowmetry is to record the urinary flow rate and flow pattern coming from detrusor contraction by using uroflowmeter. This is a easy and uninvaded method to describe the low urinary tract during micturition objectively. Urinary flow rate represents the whole process of bladder emptying, and reflects function of bladder, neck of bladder, urethra and detrusor during micturition and relationship among them. Parameters derived from uroflowmetry are frequently used in the evaluation and reassessment of children presenting with lower urinary tract dysfunction. For kids, the dynamics and functional disturbances of the lower urinary tract are quite different from those inadults, and often associated with no identifiable anatomical abnormalities, and the normal bladder-sphincteric function represents continuous changes and evolution that occur as growth and maturation take place. More confusingly, one type of bladder dysfunction may often progress with time and evolve imperceptibly into another, without a sharp distinction between the different stages. This is further confounded by a lack of age-and gender-specific normal reference values for various urodynamic parameters, especially for the young age groups. Uroflowmetry is a uninvaded method to examine bladder and urethra function, which is more acceptable for kids. However, the nomograms of uroflowmetry parameters have been constructed inadequately. As a important part of uroflowmetry, urinary flow curve reflects urinary flow pattern sensitively. In staccato voiding, the urinary stream is often delayed after the onset of detrusor contraction and is typically interrupted, resulting in a few small squirts of urine passed in quick succession. Staccato curves do not touch the baseline during the void and staccato flows showed at least 1 dip to greater than a quarter of curve which could not be explained by questioning child (ie the flow meter had not moved, urine had not been in danger of overshooting the receptacle, child was not disturbed, etc). It was reported that staccato voiding, observed in 20 to 70 percent of infants with normal lower urinary tracts in different series, tended to disappear with increasing age and were thought to represent variations between individual infants in the maturation of detrusor and sphincteric coordination . The main objective of this thesis is to analyze the parameters of urine flow and investigate the incidence of staccatourine flow curve in healthy children.Materials and methodsOne hundred sixty nine Chinese healthy children (81 boys, 88 girls) aged from 8 to 13 year-old (mean age 10.3y + 1.6y) was included in this uroflowmetry study. Post-void urine was estimated by ultrasound within 5 minutes of micturition to confirm complete emptying. We used Dantec DUET Logic uroflowmeter which is the rotating disk electronic uroflowmeter whose reliability has been shown by previous study. The study was performed privately when the child desired to void. Usual voiding practice was maintained and children were asked to void spontaneously over a flowmeter. Boys voided in a standing position while girls were seated with adequate foot support. Voided Volume in all cases was more than 50 ml. The cases with staccato urine flow curve were analyzed to evaluate the incidence and its relation to age, sex and voided volume. Data were tabulated and analyzed using SPSS 11.0 software, and p<0.05 is considered significant.Results1. Maximum flow rates in healthy boys is 20.1 + 5.3 ml/s (8-9y), 21.6 +5.5 ml/s (10-lly), 26.2+7.0 ml/s (12-13y), and 21.7+6.1 (8-9y), 25.7+6.8 (10-lly), 28.1 + 7.5 (12-13y) in girls. Maximum flow rates are higher in girls than boys (P<0.05) and increase with age or volume. Average flow rates also increase with age (P<0.05) and there was nosignificant difference between genders (P<0.05) . 2. Fifty-three cases (24boys, 30girls) presented staccato urine flow curve and the incidence was 31.9% for all children. The incidence was 29.6% and 34.1% in boys and girls respectively, and there were no significant differences between boys and girls. In boys the incidence of staccato urine flow curve decreased with age, but it didn't correlate with age in girls. We noted the incidence was correlated tightly with voided volume, increased with it in both boys and girls. For children with staccato urine flow curve, boys showed flow time and time to Qmax m children with staccato urine flow curve were higher than those with normal curve, and Qmax, Qave and PVR incidence of them had no significant differences.Conclusions1. Bladder function is changing and developing with children's growing up , and parameters of uroflowmetry are also various in different age. Maximum and average flow rates increase with age or volume.2. The staccato urine flow curve in healthy children is common, and influenced by age and urine volume. It is important to evaluate staccato urine flow combining with PVR. Staccato urine flow curve may service as a parameter for screening the bladder dysfunction in children.
|
PDF Full Text Request