Variability, Related Factors and Normal Reference Value of Post-Void Residual Urine in Healthy Kindergarteners

Recent developments in diagnostic ultrasound for lower urinary tract function

Ultrasonography (US) is an essential tool in the clinical management of lower urinary tract dysfunction (LUTD), including lower urinary tract symptoms, overactive bladder, and benign prostatic hyperplasia, in which prostatic volume and post-void residual volume are routinely used to evaluate the pathophysiological characteristics of afflicted patients. US can also be employed to diagnose hydronephrosis and bladder calculus as complications of severe LUTD. Moreover, US is essential for identifying pathophysiological characteristics and surgical indications, predicting disease development and drug efficacy, and monitoring bladder function improvement by means of such parameters as bladder wall thickness, prostatic urethral length, intravesical prostatic protrusion, and prostatic urethral angulation/angle. Herein, I narratively review the recent advances in US approaches for the management of LUTD, especially in adult males.

Assessment of lower urinary tract function in pediatrics using ultrasonography

Ultrasound imaging is a less invasive imaging modality without radiation exposure and is available for repeated tests. It is the gold standard examination for diagnosing and managing disorders of the urinary tract, including lower urinary tract dysfunction (LUTD) in pediatric urology. Ultrasound imaging is effective for screening underlying diseases and determining treatment strategies. Ultrasound examination at the bedside should focus on post-voided residual urine (PVR), bladder wall thickening, renal morphology, and rectal diameter. Since PVR must be tested immediately after voiding, examining infants who cannot complain of the urge to void is difficult. PVR measurement combined with a 4-h voiding observation or alarm system activated by urine is recommended for these infants. Early diagnosis is important because LUTD is associated with the risk of morbid residual urine and high voiding pressure, which can result in renal deterioration, urinary leakage, and febrile urinary tract infection.

Age- and gender-specific normal post void residual urine volume in healthy adolescents

INTRODUCTION

Elevated post void residual (PVR) is a significant risk factor for urinary tract infections (UTI). It is also a significant predictor of treatment outcomes in cases of vesicoureteral reflux, pediatric enuresis, and non-neurogenic LUT dysfunction. However, the absence of age-specific nomograms for adolescents may limit PVR's use in clinical practice.

OBJECTIVE

To establish age- and gender-specific normal PVR urine volume in adolescents.

MATERIAL AND METHODS

Healthy adolescents aged 12-18 years were recruited to undergo two uroflowmetry and PVR studies whenever they felt the urge to urinate. Adolescents with neurological disorders, known LUT dysfunction or UTI were excluded.

RESULTS

A total of 1050 adolescents were invited, but only 651 consented. Fourteen participants were excluded due to low bladder volume (BV < 100 ml) in both assessments (n = 12), BV < 100 ml in one assessment (n = 1), or failure to provide relevant history (n = 1). From the 1084 uroflowmetry and PVR obtained from 637 adolescents, 190 results were further excluded due to artefacts (n = 152), BV < 100 ml (n = 27), PVR >100 ml (n = 5) and missing information (n = 6). Ultimately, 894 uroflowmetry and PVR from 605 adolescents (mean age 14.6 ± 1.5 years) were analyzed. PVRs were higher in adolescents aged 15-18 years than in those aged 12-14 years (P < 0.001). Moreover, they were higher in females than in males (P < 0.001). Multivariate analysis revealed that PVR was positively influenced by age (P = 0.001) and BV (P < 0.001). The age- and gender-specific percentiles of PVR in ml and percentage of BV were calculated. We recommend a repeat PVR and close monitoring if PVR is above the 90th percentile, i.e., PVR >20 ml (7% BV) for males of both the age groups, and PVR >25 ml (9% BV) and PVR >35 ml (>10% BV) for females aged 12-14 and 15-18 years, respectively. Further investigation may be warranted if the repeat PVR is above the 95th percentile, i.e., PVR >30 ml (8% BV) and >30 ml (11% BV) for males aged 12-14 and 15-18 years, respectively, and PVR >35 ml (11% BV) and >45 ml (13% BV) for females aged 12-14 and 15-18 years, respectively.

CONCLUSION

PVR increases with age and varies by gender; thus, age-and gender-specific reference values should be used. Further data from other countries is required to determine whether the study's recommendations can be applied globally.

Asian guidelines for urinary tract infection in children

The followings are the level of evidence (LE) and grade of recommendation (GR) on pediatric UTI in Asia. Classification according to the sites of infection (lower versus upper tract), the number of episode (first versus recurrent), the severity (simple versus severe), or the existence of complicating factor (uncomplicated versus complicated) is useful to differentiate children with UTI whether they are at risk of renal damage or not (LE: 2, GR: B). Diagnosis of UTI requires both urinalysis that suggests infection and positive urine culture (LE:3, GR B). For pre-toilet trained children, urine specimen for culture should be collected by urethral catheterization or suprapubic aspiration. For toilet trained children, midstream clean catch urine is reliable (LE: 3, GR: A). Urine culture is considered positive if it demonstrates growth of a single bacterium with the following colony counts: (1) any growth by suprapubic aspiration, (2) >5 × 104 CFU/ml by urethral catheterization, or (3) >105 CFU/ml by midstream clean catch (LE:3, GR: B). For children with febrile UTI, renal and bladder ultrasonography (RBUS) should be routinely performed as soon as possible (LE: 3, GR: C). RBUS should be followed up 6 months later in children with acute pyelonephritis and/or VUR (LE: 3, GR: C). Acute DMSA scan can be performed when severe acute pyelonephritis or congenital hypodysplasia is noted on RBUS or when the diagnosis of UTI is in doubt by the clinical presentation (LE: 3, GR: C). Late DMSA scan (>6 months after the febrile UTI) can be performed in children with severe acute pyelonephritis, high-grade VUR, recurrent febrile UTIs, or abnormal renal parenchyma on the follow-up RBUS (LE: 3, GR: C). Top-down or bottom-up approach for febrile UTI is suggested for the diagnosis of VUR. For top-down approach, VCUG should not be performed routinely for children after the first febrile UTI. VCUG is indicated when abnormalities are apparent on either RBUS or DMSA scan or both (LE: 2, GR: B). VCUG is also suggested after a repeat febrile UTI (LE:2, GR: B). Appropriate antibiotic should be given immediately after urine specimen for culture has been obtained (LE:2, GR: A). Initiating therapy with oral or parenteral antibiotics is equally efficacious for children (>3 months) with uncomplicated UTI (LE: 2: GR: A). The choice of empirical antibiotic agents is guided by the expected pathogen and the local resistance patterns (LE: 2, GR: A). For children with febrile UTI, the total course of antibiotic therapy should be 7-14 days (LE: 2, GR: B). Circumcision may, but not definitively, reduce the risk of febrile UTI in males and breakthrough febrile UTI in males with VUR. Circumcision should be offered to uncircumcised boys with febrile UTI and VUR in countries where circumcision is accepted by the general population (LE: 3, GR: B), while in countries where childhood circumcision is rarely performed, other measures for febrile UTI/VUR should be the preferred choice (LE: 4, GR: C). Bladder bowel dysfunction (BBD) is one of the key factors of progression of renal scarring (LE: 2). Early recognition and management of BBD are important in prevention of UTI recurrence (LE:2, GR: A). Antibiotic prophylaxis to prevent recurrent febrile UTI is indicated in children with moderate to high grade (III-V) VUR (LE: 1b, GR: A). Surgical intervention may be used to treat VUR in the setting of recurrent febrile UTI because it has been shown to decrease the incidence of recurrent pyelonephritis (LE: 2, GR: B).

Large congenital bladder diverticula in children

OBJECTIVE

Large congenital bladder diverticula (LCBD), congenital bladder diverticula (CBD) larger than 2 cm diameter, is a rare anomaly. The aim of this study was to report long-term surgical and clinical outcomes of children with LCBD.

METHODS

Medical charts of all children who were diagnosed with LCBD at our institution between April 2005 and December 2017, with at least 2 year follow-up were retrospectively reviewed. Patients' demographics, symptoms, operative technique, diverticulum size and localization, surgical outcomes and complications were recorded.

RESULTS

Fourteen patients with 18 LCBD, all male and age between 7 and 240 months (mean age: 53.5 months) were included in the study. Urinary tract infection was the main complaint in 10. Vesicoureteral reflux was detected in eight patients. Diverticula were 2-5.5 cm (mean 3.3 cm) in size. All diverticulectomies were performed transvesically and ureteroneocystostomy was added in 12 patients, 5 of whom were bilateral. No postoperative infection or recurrent reflux were observed. The median follow-up period was 4.5 years (2-12 years).

CONCLUSION

Treatment of LCBD is mostly surgical and transvesical approach for diverticulectomy was found to be a safe and effective surgical procedure in long term follow-up.

Prolonged Indwelling Urethral Catheterization as Minimally Invasive Approach for Definitive Treatment of Posterior Urethral Valves in Unstable Premature Babies

Premature newborns with posterior urethral valves (PUV) may present with medical conditions taking priority over definitive surgical care. We encountered three of such cases who underwent initial bladder decompression via transurethral catheterization and waited 2-3 weeks until they were fit enough for voiding cysto-urethrography to confirm PUV. An unexpected good urinary flow and negligible residual urine volume were documented during micturition, suggestive of valve disruption induced by insertion and prolonged duration of indwelling urethral catheter drainage. Cystoscopy documented non-obstructing remnant leaflets. Non-operative treatment may be considered as a viable alternative therapeutic option for PUV in tiny babies facing prolonged intensive care unit stay.

Ultrasound evidence of bladder outlet obstruction secondary to lichen sclerosus et atrophicus in boys (balanitis xerotica obliterans)

BACKGROUND

Lichen sclerosus (LS), (balanitis xerotica obliterans), causes pathological phimosis. Many boys present with obstructive symptoms, the cause is usually obvious on examination so ultrasound scans (USS) of the urinary tract are not routinely indicated. We review a series of abnormal USS in boys with LS.

METHODS

Retrospective note review for boys undergoing surgical treatment for LS between 2000 and 2017. Seventy-eight boys had a USS prior to surgery, those with abnormal USS form the study population. Boys with neuropathic bladder or congenital urinary tract abnormalities were excluded.

RESULTS

Nineteen of 78 boys (24%), mean age 9 years, were included. Seventeen had obstructive symptoms, 13 had culture proven UTIs, 12 had new onset incontinence. On USS 3 (17%) had acute retention, 8 (78%) had an isolated post-void residual volume (PVR) >10% of estimated bladder capacity (EBC); 3 had bladder wall thickening +/- PVR >10%, 5 had upper tract changes. Symptoms resolved with successful treatment of LS. Six boys had post treatment USS, abnormalities resolved in 5.

CONCLUSIONS

Clinicians should consider LS in boys presenting with UTIs, new onset incontinence and obstructive urinary tract symptoms. Routine USS are not indicated though should be considered in those with an atypical history or examination.

TYPE OF STUDY

Case Series.

LEVEL OF EVIDENCE

Level 4.

Bladder scan accuracy in pediatric patients: Does patient position matter?

INTRODUCTION

Despite its widespread use in pediatric urology clinics, portable bladder scanning is an insufficiently studied tool that lacks standardized protocols. Workflow at the present clinic can be impeded by scanning in the supine position, due to multiple trips to the restroom and back to the exam room.

OBJECTIVE

The current study sought to test accuracy of bladder scanning, and hypothesized that it would be equally accurate in the standing versus traditional supine position in children, given the intra-abdominal location of their bladders.

DESIGN

Sixty children from the bladder/bowel clinic were prospectively recruited. Patients had a formal supine renal/bladder ultrasound and pre-void and/or post-void assessment with scans in both the standing and supine positions. The methods were compared using repeated measures one-way ANOVA.

RESULTS

Mean age was 9.2 years. The majority (85%) were female. All bladder scan estimates except for post-void supine significantly correlated with ultrasound volume. Pre-void standing had the strongest correlation (r = 0.83). There was no difference between ultrasound and standing estimates for pre-void volumes, but supine underestimated volumes by 44.8 ml (P < 0.01) (Summary Figure). Sub-group analysis of children aged <10 years showed that pre-void scans in both positions significantly underestimated volume (12% of estimated bladder capacity for standing, 24% for supine, P < 0.05). For post-void volumes, both standing and supine overestimated measurements by 29.4 ml and 18.3 ml, respectively (both P < 0.001). Sub-group analysis based on age yielded comparable results.

DISCUSSION

It is believed that this is the first study to examine bladder scanning in different positions. Limitations included small sample size, and the study fell short of cost-effectiveness and outcome analysis to assess the real-life impact of the proposed use of standing bladder scanning in the clinic.

CONCLUSION

Standing bladder scanning may be used in place of supine. However, bladder scanning generally appeared to have poor accuracy, especially in younger children, and thus should be used with caution. In practical terms, it may decrease specificity of detecting elevated post-void residuals compared to ultrasound.

Adipose-derived stem cells-seeded bladder acellular matrix graft-silk fibroin enhances bladder reconstruction in a rat model

The unfavourable clinical outcomes of host cell-seeded scaffolds for bladder augmentation warrant improved bioactive biomaterials. This study aimed to examine the feasibility of adipose-derived stem cells (ASCs)-seeded bilayer bladder acellular matrix graft (BAMG)-silk fibroin (SF) scaffold in enhancing bladder reconstruction. Sprague Dawley rats were randomly divided into three groups: the BAMG-SF-ASCs group, the acellular BAMG-SF group and the cystotomy group. The BAMG-SF-ASCs group was sampled at 2, 4 and 12 weeks, and compared with the other groups at 12 weeks. In the BAMG-SF-ASCs group, the normal bladder contour was reformed similar to that in the cystotomy group, with abundant urothelium and smooth muscle regeneration, as well as a suitable scaffold degradation speed, and trivial fibrosis and inflammation. The ASCs seeded in BAMG-SF were maintained in the regenerated region during the 12-week experimental period and significantly enhanced the vessel density, nerve regeneration and bladder function compared with acellular BAMG-SF. In addition, the BAMG-SF-ASCs group presented elevated levels of SDF-1α, VEGF and their receptors, with an obvious increase in ERK 1/2 phosphorylation. BAMG-SF is a promising biomaterial for ASCs seeding to facilitate bladder augmentation and demonstrated an enhanced angiogenic potential possibly related to the SDF-1α/CXCR4 pathway via ERK 1/2 activation.

Acupuncture for Chronic Urinary Retention due to Spinal Cord Injury: A Systematic Review

No systematic review has been published on the use of acupuncture for the treatment of chronic urinary retention (CUR) due to spinal cord injury (SCI). The aim of this review was to assess the effectiveness and safety of acupuncture for CUR due to SCI. Three randomized controlled trials (RCTs) including 334 patients with CUR due to SCI were included. Meta-analysis showed that acupuncture plus rehabilitation training was much better than rehabilitation training alone in decreasing postvoid residual (PVR) urine volume (MD -109.44, 95% CI -156.53 to -62.35). Likewise, a combination of acupuncture and aseptic intermittent catheterization was better than aseptic intermittent catheterization alone in improving response rates (RR 1.23, 95% CI 1.10 to 1.38). No severe adverse events were reported. In conclusion, acupuncture as a complementary therapy may have a potential effect in CUR due to SCI in decreasing PVR and improving bladder voiding. Additionally, acupuncture may be safe in treating CUR caused by SCI. However, due to the lack of high quality RCTs, we could not draw any definitive conclusions. More well-designed RCTs are needed to provide strong evidence.

Elevated postvoid residual urine volume predicting recurrence of urinary tract infections in toilet-trained children

BACKGROUND

The aim of this study was to examine whether toilet-trained children with a history of febrile urinary tract infection (fUTI) and elevated postvoid residual (PVR) urine volume according to a recently published PVR nomogram were at greater risk of UTI recurrence.

MATERIALS AND METHODS

One month after recovery from febrile UTI, constipation was diagnosed according to the Rome III criteria, and lower urinary tract (LUT) function was evaluated with two sets of uroflowmetry and PVR by ultrasonography. For children aged ≦ 6 and ≧ 7 years, elevated PVR is defined as >20 and >10 ml, respectively. Cox proportion hazards regression was used to evaluate the risk factors for recurrence of UTI.

RESULTS

Between 2005 and 2011, 60 children aged 6.5 ± 2.5 years (boy:girl ratio 27:33) were enrolled for analysis. Univariate analysis showed that recurrent febrile UTI was more commonly observed in children with elevated PVR [repetitive elevated PVR: hazard ratio (HR) 5.75, 95% confidence interval (CI) 1.41-23.4; one elevated PVR: HR 4.53, 95% CI 1.01-20.2] and high-grade vesicoureteral reflux (VUR; HR 4.53, 95% CI 1.46-14.07). Multivariate analysis showed that younger age (HR 1.37, 95% CI 1.03-1.82, p < 0.01) and elevated PVR (HR 2.88, 95% CI 1.44-5.73, p = 0.01) were significant, independent risk factors for recurrent febrile UTI--but not gender, presence of high-grade VUR and constipation.

CONCLUSION

Elevated PVR defined by the new PVR nomogram predicted recurrent UTI in children with history of febrile UTI. Care should be taken to manage children with elevated PVR.

Incomplete bladder emptying is associated with febrile urinary tract infections in infants

OBJECTIVE

To investigate lower urinary tract dysfunction in pre-toilet trained infants with and without history of febrile UTI (f-UTI).

MATERIALS AND METHODS

Pre-toilet trained infants with f-UTI (Group 1) from pediatric nephrology and urology clinics, and those without f-UTI (Group 2) from infant-care centers were enrolled for the present study. Infants in Group 1 underwent four-hourly (4-H) observations for at least one month after treatment for UTI. Voided volume (VV) and post-void residual urine (PVR) were measured by weighting diaper and suprapubic ultrasound after finishing voiding, respectively. Average PVR was defined as the mean value of PVR during 4-H observation. Interrupted voiding was defined as two or three voidings within 10 min. Voiding efficiency was defined as VV/(VV+PVR).

RESULTS

The mean ages of Group 1 (n=64) and Group 2 infants (n=56) were 10.6±7.5 months vs 10.2±5.1 months, respectively (p=0.70). Group 1 infants had significantly higher voiding frequency (3.0 times±1.2 vs 2.6 times±0.9, p=0.04), average PVR (14.5 ml±14.2 vs 8.9 ml±8.8, p<0.01) and lower voiding efficiency (71.2%±20.5 vs 80.2%±18.5, p=0.01) than Group 2. ROC curve analysis showed that the optimal cutoff values for PVR and voiding efficiency to differentiate Group 1 and Group 2 infants were 10 ml and 80%, respectively. Group 1 infants had significantly more repeat elevated PVR (≧10 ml) and repeat low voiding efficiency (≦80%) than Group 2 (44.8% vs 22.4%, p=0.03; 62.0% vs 28.6%, p<0.01, respectively).

CONCLUSION

Pre-toilet trained infants with f-UTI were associated with elevated PVR and lower voiding efficiency than normal controls.

A practical guide to urinary tract ultrasound in a child: Pearls and pitfalls

The aim of this review article is to equip the sonographer with the necessary knowledge to perform a detailed and clinically relevant assessment of the urinary tract in a child. Many of the techniques and principles used in the imaging of the urinary tract in adults can be applied to children. There are, however, notable differences with which the sonographer should be familiar. There is often a certain amount of trepidation when asked to image a child, but there are a number of simple steps that can make the process easier and more fulfilling. This article begins with advice on how to maintain cooperation in a child and the differences in the technical aspects of imaging of children. This is followed by a detailed review of the different pathologies that may be encountered, as well as highlighting information that is particularly relevant to the clinician looking after the child.

Age- and gender-specific nomograms for single and dual post-void residual urine in healthy children

PURPOSE

To establish the first age- and gender-specific nomograms for single and two consecutive tests for post-void residual urine (PVR).

MATERIAL AND METHODS

Healthy children aged 4-12 years were enrolled for two sets of uroflowmetry and PVR. The first PVR and the lower value of the two consecutive PVRs of each child with a voided volume ≥50 ml were included for construction of Single- and Dual-PVR nomograms. Children with possible urinary tract infection or lower urinary tract dysfunctions were excluded.

RESULTS AND LIMITATIONS

Totally, 1,128 children (583 boys and 545 girls) with a mean age of 7.7 ± 2.2 years were eligible for analysis. The 95th percentile of Single-PVR for all children was 27.2 ml, or 19.2% of bladder capacity (BC), while that for Dual-PVR were 11.2 ml or 6.0% of BC, respectively. Multivariate studies showed that PVR was positively associated with BC, negatively associated with age, higher in boys than girls, and higher in abnormal uroflow patterns. For children aged ≤6 years, a single PVR >30 ml or >21% BC, or repetitive PVR >20 ml or >10% BC can be regarded as elevated. For children aged ≥7 years, a single PVR >20 ml or 15% BC, or repetitive PVR >10 ml or 6% BC can be redefined as elevated.

CONCLUSIONS

Age, gender, and BC should be taken into considerations at interpretation of PVR tests in children. Repeating PVR test is recommended when a single PVR is higher than the 95th percentile of age- and gender-specific PVR. Neurourol. Urodynam. 32: 1014-1018, 2013. © 2013 Wiley Periodicals, Inc.

The performance of silk scaffolds in a rat model of augmentation cystoplasty

The diverse processing plasticity of silk-based biomaterials offers a versatile platform for understanding the impact of structural and mechanical matrix properties on bladder regenerative processes. Three distinct groups of 3-D matrices were fabricated from aqueous solutions of Bombyx mori silk fibroin either by a gel spinning technique (GS1 and GS2 groups) or a solvent-casting/salt-leaching method in combination with silk film casting (FF group). SEM analyses revealed that GS1 matrices consisted of smooth, compact multi-laminates of parallel-oriented silk fibers while GS2 scaffolds were composed of porous (pore size range, 5-50 μm) lamellar-like sheets buttressed by a dense outer layer. Bi-layer FF scaffolds were comprised of porous foams (pore size, ~400 μm) fused on their external face with a homogenous, nonporous silk film. Silk groups and small intestinal submucosa (SIS) matrices were evaluated in a rat model of augmentation cystoplasty for 10 weeks of implantation and compared to cystotomy controls. Gross tissue evaluations revealed the presence of intra-luminal stones in all experimental groups. The incidence and size of urinary calculi was the highest in animals implanted with gel spun silk matrices and SIS with frequencies ≥57% and stone diameters of 3-4 mm. In contrast, rats augmented with FF scaffolds displayed substantially lower rates (20%) and stone size (2 mm), similar to the levels observed in controls (13%, 2 mm). Histological (hematoxylin and eosin, Masson's trichrome) and immunohistochemical (IHC) analyses showed comparable extents of smooth muscle regeneration and contractile protein (α-smooth muscle actin and SM22α) expression within defect sites supported by all matrix groups similar to controls. Parallel evaluations demonstrated the formation of a transitional, multi-layered urothelium with prominent uroplakin and p63 protein expression in all experimental groups. De novo innervation and vascularization processes were evident in all regenerated tissues indicated by Fox3-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. In comparison to other biomaterial groups, cystometric analyses at 10 weeks post-op revealed that animals implanted with the FF matrix configuration displayed superior urodynamic characteristics including compliance, functional capacity, as well as spontaneous non voiding contractions consistent with control levels. Our data demonstrate that variations in scaffold processing techniques can influence the in vivo functional performance of silk matrices in bladder reconstructive procedures.

Adequacy of paediatric renal tract ultrasound requests and reports in a general radiology department

BACKGROUND

According to current guidelines, US is the most important modality for imaging urinary tract infections (UTI) in children.

OBJECTIVES

(1) To assess the adequacy of paediatric renal US requests and reports in a general radiology department, and correlate the request adequacy and the performing radiologist's experience with report adequacy. (2) To determine the yield of abnormal findings.

MATERIALS AND METHODS

Retrospective review of renal US requests. The information was scored: requests 0-3 (3 as highest adequacy) and reports 0-21 (21 as highest adequacy). Correlation tests used included Spearman's correlation, Kruskal-Wallis test, Chi-square test of independence and Fisher exact test.

RESULTS

Mean report adequacy score was 6.67/21. Trainees did 87% of all scans and performed better (score 6.76) than the staff radiologists (score 6.08). Hydronephrosis was the most common abnormality. There was no correlation between request or reporter rank and reporting adequacy.

CONCLUSION

Renal US requests and reports are inadequate. To improve reporting standards for trainees and specialists, a renal ultrasound reporting template was designed for use.

Early initiation of toilet training for urine was associated with early urinary continence and does not appear to be associated with bladder dysfunction

OBJECTIVE

To report the relationship between the ages initiating toilet training for urinary continence (TTU) and bladder function in healthy kindergarteners.

PATIENTS AND METHODS

In 3 years, we evaluated urinary continence status and bladder function in 318 healthy kindergarteners. Children with congenital anomaly, neurological disorder, or developmental disability were excluded. A parent completed the questionnaire including the age at initiation and the duration of TTU, the current status of daytime and nighttime continence, the age of attaining daytime and nighttime continence, frequency of defecation and Bristol Stool Scale. All children underwent uroflowmetry and post-void residual urine (PVR) examinations.

RESULTS

Finally, 235 respondents (106 boys/129 girls, mean age = 4.8 ± 0.9 years) were eligible for analysis. The mean age initiating TTU was 24.4 ± 8.4 months (range: 1-52 months). Girls started TTU earlier than boys (23.3 months vs. 25.7 months, P = 0.03). Children started daytime TTU earlier (≤ 18, 19-24, and >24 months, N = 66, 71, and 98, respectively) was associated with earlier attainment of both daytime and nighttime continence (correlation coefficient = 0.60 and 0.31, respectively, P < 0.01). Children started nighttime TTU earlier (<30 months vs. ≥ 30 months) was associated with early attainment of nighttime continence and lower rate of enuresis (14.3% vs. 33.3%, P < 0.01). The prevalence rate of repeat abnormal uroflow patterns and repeat elevated PVR (>20 ml) was not different between early and late TTU.

CONCLUSION

Early toilet training for urine was associated with early attainment of both daytime and nighttime urinary continence, and does not appear to be associated with bladder dysfunction.

Lower urinary tract dysfunction in childhood

Lower urinary tract syndrome is common in children. Incontinence, urinary tract infection, vesicoureteral reflux, and constipation are commonly associated with this syndrome. Examining the clinical history of the afflicted patient plays a major role in the accurate diagnosis and treatment of lower urinary tract disorder. Along with pharmacologic treatment, pelvic floor muscle retraining, biofeedback therapy, and adaptation of a healthy lifestyle are advocated for rapid recovery of patients.