Age related nocturnal urine volume and maximum voided volume in healthy children: reappraisal of International Children's Continence Society definitions

Effect of desmopressin on water and solute circadian rhythms in treatment-naïve children with monosymptomatic enuresis and nocturnal polyuria

BACKGROUND

Enuresis has a complex pathophysiology involving nocturnal polyuria, reduced bladder capacity at nighttime, and impaired arousability. Desmopressin has long been used as a treatment. However, approximately 30% of children do not fully respond to it, suggesting the involvement of other factors. Solute handling and osmotic excretion have been studied in refractory patients. Nevertheless, data on the effect of desmopressin on these factors are sparse.

METHODS

We conducted a post hoc analysis of the SLEEP study. We analyzed the circadian rhythm of solute and water excretion before and after desmopressin in 30 children with monosymptomatic enuresis and nocturnal diuresis > 100% of expected bladder capacity by means of a 24-h urine concentration profile (four daytime and four nighttime urine portions at equivalent time intervals).

RESULTS

Under desmopressin, nocturnal diuresis (rate) and Na/creatinine ratio were significantly lower compared to day values (p = 0.009, p = 0.021, respectively). Osmolality, Na/creatinine, and osmotic excretion showed a significant day vs. night variance only after desmopressin. Nighttime osmotic and sodium excretion were significantly lower (p = 0.004, p = 0.019, respectively) under treatment, indicating the impact of desmopressin on kidney sodium handling. During desmopressin treatment, nocturnal diuresis (rate) showed strong positive correlation with nighttime Na/creatinine (r = 0.436, p < 0.05) and very strongly with nighttime osmotic excretion (r = 0.875, p < 0.0001). However, no correlation was observed with osmolality under desmopressin treatment.

CONCLUSIONS

The anti-enuretic and antidiuretic effects of desmopressin therapy are not only related to urinary concentration and nocturnal diuresis but also to the amelioration of circadian rhythms of sodium and solute handling.

Bladder capacity in an elimination communication infant: a case report

BACKGROUND

Bladder capacity is essential in assessing children with voiding dysfunction, yet it is currently unclear how best to determine a benchmark bladder capacity; various formulas have been proposed.

CASE PRESENTATION

This report details the unique case of an elimination communication Caucasian infant (< 2 years old) who achieved nighttime and daytime dryness by 6 months of age. His first morning voids were measured from 8 to 20 months of age and compared with three formulas: (1) the Koff formula, a widely used formula based on fill volumes in anesthetized infants; (2) the Kaefer formula, a formula based on fill volume in nonanesthetized infants; and (3) the Holmdahl formula, a formula based on frequency-volume charts in normal infants.

CONCLUSION

This infant's first morning void was found to be most consistent with Kaefer's formula. Further research is required to determine if formulas based on fill volume in nonanesthetized infants provide the more accurate benchmark bladder capacity in infants.

Circadian rhythm of water and solute excretion in nocturnal enuresis

BACKGROUND

Nocturnal polyuria (NP) due to a suppressed vasopressin circadian rhythm is a well-documented pathogenetic mechanism in enuresis, mainly studied in monosymptomatic enuresis. A substantial percentage of patients do not respond to desmopressin. This suggests that NP may not only be related to vasopressin, but that other kidney components play a role. Solute handling and osmotic excretion have been investigated in the past, especially in refractory patients. Nevertheless, data in treatment-naïve populations with information on timing overnight are sparse. This study aims to investigate the diuresis and solute excretion in treatment-naïve patients with or without NP, with emphasis on circadian rhythms.

METHODS

Retrospective analysis of 403 treatment-naïve children 5-18 years with severe enuresis (> 8 nights/2 weeks). Circadian rhythms were evaluated by a 24-h urine collection in 8 timed portions (4 day, 4 nighttime) at in-home settings. Urine volume, osmolality, and creatinine were measured. Patients were subdivided into three groups according to nocturnal diuresis (ND) and Expected Bladder Capacity (EBCage) ratio: (a) < 100%, (b) 100-129%, (c) > 130%.

RESULTS

All groups maintained circadian rhythm for diuresis and diuresis rates. Patients with higher ND (100-129% and > 130% EBCage) had higher daytime volumes and less pronounced circadian rhythm. In the ND group > 130% EBCage, the ND rate was higher during the first night collection and osmotic excretion was significantly higher overnight.

CONCLUSIONS

Overall 24-h fluid intake (reflected by 24-h diuresis) and nutritional intake (24-h osmotic excretion) might play a role in enuresis. Increased diuresis rate early in the night can be important in some patients, whereas the total night volume can be important in others. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Impact of New vs. Old International Children's Continence Society Standardization on the Classification of Treatment Naïve Enuresis Children at Screening: The Value of Voiding Diaries and Questionnaires

Expert consensus papers recommend differentiating enuresis using questionnaires and voiding diaries into non- (NMNE) and monosymptomatic enuresis (MNE) is crucial at intake to decide the most appropriate workout and treatment. This national, Belgian, prospective study investigates the correlation, consistency, and added value of the two methods, the new against the old International Children's Continence Society (ICCS) definitions, and documents the prevalence of the two enuresis subtypes in our population. Ninety treatment-naïve enuretic children were evaluated with the questionnaire, and the voiding diary and the two clinical management tools were compared. Almost 30% of the children had a different diagnosis with each method, and we observed inconsistencies between them in registering Lower Tract Symptoms (κ = -0.057-0.432 depending on the symptom). Both methods had a high correlation in identifying MNE (rs = 0.612, p = 0.001) but not for NMNE (rs = 0.127, p = 0.248). According to the latest ICCS definitions, the incidence of MNE was significantly lower (7 vs. 48%) with the old standardization.

Conclusion

The voiding diary and the questionnaire, as recommended by the ICCS at the screening of treatment-naïve enuretic patients, are considerably inconsistent and have significantly different sensitivities in identifying LUTS and thus differentiating MNE from NMNE. However, the high incidence of LUTS and very low prevalence of MNE suggest that differentiating MNE from NMNE to the maximum might not always correlate with different therapy responses.

Evaluating nocturnal polyuria in Japanese children with nocturnal enuresis

BACKGROUND

The purpose of this study was to assess whether enuretic Japanese patients with nocturnal polyuria (NP) who met Hoashi's criteria (6-9 years: ≥200 mL; 10 years and older: ≥250 mL) met the International Children's Continence Society (ICCS; expected bladder capacity × 130%) and Rittig's criteria for nocturnal polyuria (>[age+9] × 20 mL). We also compared the effectiveness of 1-desamino-8-d-arginine vasopressin (DDAVP) with the three criteria.

METHODS

Fifty-four patients who had NP with normal bladder capacity were enrolled: 36 boys (67%); median age, 8 (interquartile range: 7-9). We compared the diagnostic differences between the Hoashi's criteria and international standards (ICCS and Rittig's) for NP and the short-term effects of DDAVP. The patients received DDAVP for 8 weeks; we evaluated the association between each evaluation method and the effects of therapy.

RESULTS

Only 17% of the patients met both Hoashi's and ICCS criteria, whereas 26% met both Hoashi's and Rittig's criteria. The therapeutic effect of DDAVP did not differ significantly between these two groups: there was an effective rate of 73% (Hoashi's criteria) versus 50% (ICCS criteria), P = 0.19, and an effective rate of 71% (Hoashi's criteria) versus 62% (Rittig's criteria), P = 0.84.

CONCLUSIONS

Hoashi's criteria are widely used but, according to both the ICCS and Rittig's criteria, approximately 80% of the patients did not fulfill the definition of NP. However, 8 weeks after the DDAVP treatment began, no significant difference was observed in the therapeutic effect of DDAVP according to each set of criteria. The definition of NP should account for the physical disparities between Japanese people and Westerners.

Non-invasive bladder function measures in healthy, asymptomatic female children and adolescents: A systematic review and meta-analysis

BACKGROUND

Lower urinary tract symptoms (LUTS) are common in children and adolescents. Non-invasive tests evaluating bladder function are generally preferred over invasive tests, yet few studies have explored the range of normative values for these tests in healthy, asymptomatic children.

OBJECTIVE

To define normative reference ranges for non-invasive tests of bladder function in healthy, asymptomatic girls and adolescents.

STUDY DESIGN

A comprehensive search strategy was performed in seven electronic databases through October 2019. English-language studies reporting data on voiding frequency, voided and postvoid residual volumes (PVR) and uroflowmetry results in healthy, asymptomatic girls (mean age ≥ 5 years) were included. Two independent reviewers performed study review, data extraction, and quality assessment. Overall mean estimates and 95% confidence intervals for each bladder function parameter were calculated using random effects models, and 95% normative reference values were estimated.

RESULTS

Ten studies met eligibility criteria for the meta-analysis (n = 2143 girls, age range: 3-18). Mean estimates of maximum voided volume and PVR were 233.4 ml (95% CI 204.3-262.6; n = 1 study) and 8.6 ml (95% CI 4.8-12.4; n = 2 studies) respectively. Pooled mean estimates for uroflowmetry parameters were: 21.5 ml/s (95% CI 20.5-2.5) for maximum flow rate (n = 6 studies), 12.5 ml/s (95% CI 11.2-13.8) for mean flow rate (n = 6 studies), 6.8 s (95% CI 4.4-9.3) for time to maximum flow (n = 3 studies), 15.7 s (95% CI 13.0-18.5) for flow time (n = 3 studies), and 198.7 ml (95% CI 154.2-234.2) for voided volume (n = 9 studies). No studies reported estimates of voiding frequency. Between-study heterogeneity was high (89.0-99.6%).

CONCLUSIONS

Although we were able to calculate pooled mean estimates for several parameters, the small number of included studies and the wide age ranges of participants preclude generalization of reference values to all healthy girls. Further research is needed to determine normative reference values within specific age groups.

Desmopressin response in nocturnal enuresis without nocturnal polyuria in Japanese children

OBJECTIVES

To evaluate whether the efficacy of desmopressin differs between patients with and without nocturnal polyuria.

METHODS

A total of 65 treatment-naïve children with monosymptomatic nocturnal enuresis were enrolled (45 boys; median age 8.9 years). Patients received desmopressin as their first-line treatment. Four different standards were used (Akashi and Hoashi >0.9 mL/kg/sleeping hour; Hamano >[age + 2] × 25 × 130% mL; the International Children's Continence Society >[age + 1] × 30 × 130% mL; and Rittig >[age + 9] × 20 mL) to assess nocturnal polyuria. The effectiveness of desmopressin was compared between patients with and without nocturnal polyuria according to each standard. A response was defined as a reduction in wet nights of >50%.

RESULTS

The desmopressin treatment efficacy rate was 54% for polyuria and 67% for non-polyuria patients (P = 0.20), 45% for polyuria and 68% for non-polyuria patients (P = 0.08), 54% for polyuria and 59% for non-polyuria patients (P = 0.80), and 52% for polyuria and 61% for non-polyuria patients (P = 0.61), for the Akashi and Hoashi's, Hamano's, International Children's Continence Society and Rittig's standards, respectively.

CONCLUSIONS

No difference was observed in the short-term clinical efficacy of desmopressin regardless of the presence of nocturnal polyuria. Thus, this might be a feasible treatment option for patients with nocturnal enuresis without nocturnal polyuria.

An Integrated Paediatric Population PK/PD Analysis of dDAVP: How do PK Differences Translate to Clinical Outcomes?

INTRODUCTION

The bioequivalence of two formulations of desmopressin (dDAVP), a vasopressin analogue prescribed for nocturnal enuresis treatment in children, has been previously confirmed in adults but not in children. In this study, we aimed to study the pharmacokinetics (PK) and pharmacodynamics (PD) of these two formulations, in both fasted and fed children, including patients younger than 6 years of age.

METHODS

Previously published data from one PK study and one PK/PD study in children aged between 6 and 16 years were combined with a new PK/PD study in children aged between 6 months and 8 years, and analysed using population PK/PD modelling. Simulations were performed to further explore the relative bioavailability of both formulations and evaluate current dosing strategies.

RESULTS

The complex absorption behaviour of the lyophilizate was modelled using a double input, linked to a one-compartmental model with linear elimination and an indirect response model linking dDAVP concentration to produced urine volume and osmolality. The final model described the observed data well and elucidated the complexity of bioequivalence and therapeutic equivalence of the two formulations. Simulations showed that current dosing regimens using a fixed dose of lyophilizate 120 μg is not adequate for children, assuming children to be in the fed state when taking dDAVP. A new age- and weight-based dosing regimen was suggested and was shown to lead to improved, better tailored effects.

CONCLUSIONS

Bioequivalence and therapeutic equivalence data of two formulations of the same drug in adults cannot be readily extrapolated to children. This study shows the importance of well-designed paediatric clinical trials and how they can be analysed using mixed-effects modelling to make clinically relevant inferences. A follow-up clinical trial testing the proposed dDAVP dosing regimen should be performed.

CLINICAL TRIAL REGISTRATION

This trial has been registered at www.clinicaltrials.gov (identifier NCT02584231; EudraCT 2014-005200-13).

Nocturnal enuresis in children: The role of arginine-vasopressin

Nocturnal enuresis is the involuntary pass of urine during sleep beyond the age of 5 years. It is a common condition in childhood and has an impact on the child's well-being. Research into the pathophysiology of the condition in the last decades has led to a paradigm shift, and enuresis is no longer considered a psychiatric disorder but rather a maturation defect with a somatic background. An excess urine production during sleep is a common finding in children with enuresis and disturbances in the circadian rhythm of arginine-vasopressin (AVP) is found in the majority of children with nocturnal polyuria. Children with enuresis and nocturnal polyuria lack the physiologic increase in AVP levels during sleep and treatment with the AVP analogue desmopressin can restore this rhythm and lead to dry nights. The reasons for this aberrant circadian AVP rhythm are not established. Furthermore, not all children with enuresis and nocturnal polyuria can be successfully treated with desmopressin suggesting that factors beyond renal water handling can be implicated such as natriuresis, hypercalciuria, and sleep-disordered breathing. The advances in the research of the genetic background of the condition may shed further light on the enuresis pathophysiology.

Prevalence of nocturia and fecal and urinary incontinence and the association to childhood obesity: a study of 6803 Danish school children

INTRODUCTION

Fecal and urinary incontinence are common disorders in children. Obesity and its associated comorbidities have become increasingly common, and a relation between obesity, nocturia, incontinence, and nocturnal enuresis has been suggested.

OBJECTIVE

This large scale population study aims to determine the prevalence of fecal incontinence (FI), daytime urinary incontinence (DUI), nocturnal enuresis (NE), and nocturia in children at school entry and in adolescence and to clarify whether obesity is associated to any of the aforementioned symptoms.

STUDY DESIGN

First-grade children and their parents and adolescents in the seventh to ninth grades were interviewed in relation to school nurse visits. The interview included questions on whether incontinence or nocturia were experienced at least once per month. The participants' age was recorded, and weight and height were measured. Body mass index (BMI) was calculated and age standardized by the use of BMI-standard deviation score (SDS), with reference to World Health Organization normative BMI data. Obesity was defined as BMI-SDS >2. Associations between obesity and incontinence and nocturia were quantified by odds ratio (OR).

RESULTS

Completed interview questionnaires and measurements were obtained from 4002 children (95.1%) in the child population and 2801 adolescents (84.4%) in the adolescent population. The mean age of children was 6.45 ± 0.39 years, and 4.4% were obese. Overall 11.2% reported FI, 21.8% DUI, 16.8% NE, and 31.4% experienced nocturia. Obesity was associated with FI in first-grade boys (OR 1.86 compared with normal weight). Mean age of adolescents was 13.9 ± 0.85 years, and 7.6% of adolescent boys and 5.5% of the girls were obese. Fecal incontinence was reported by 2.1% of the adolescents, 4.5% had DUI, 1.0% stated to have NE, and 32.3% reported nocturia. Obesity was significantly associated with nocturia in adolescents (OR 1.74-2.01).

DISCUSSION

The prevalence of nocturia seems constant throughout childhood and adolescent life; this has not previously been documented. Incontinence is very common at school entry, with DUI reported more frequently than enuresis by both children and adolescents. Obesity is associated with nocturia in adolescents and FI in first-grade boys, but no significant association between obesity and NE or DUI is found. Strength of this study is the very high participation rates, but the study does not reveal information on previous treatment, subtype, or severity of symptoms.

CONCLUSIONS

Incontinence is very common in children. One-third of both children and adolescents experience nocturia. Obesity is associated with FI in first-grade boys and nocturia in adolescents.

'Frequently recurring' nocturnal polyuria is predictive of response to desmopressin in monosymptomatic nocturnal enuresis in childhood

INTRODUCTION

The nocturnal polyuria is considered a significant predictive value for response to desmopressin. The cutoff value useful to define nocturnal polyuria is still a matter of debate. Moreover, it is current notion that maximal voided volume (MVV) could be used as a predictor for desmopressin response.

OBJECTIVE

The objective of this study was to assess the impact of different definitions of nocturnal polyuria (and of its frequency) and MVV in predicting the response to desmopressin.

STUDY DESIGN

A total of 103 patients with frequent monosymptomatic nocturnal enuresis (≥4 wet nights/week) were enrolled. A bladder diary over a 4-day period was collected. The MVV was defined as the highest micturition volume detected at bladder diary. Nocturnal diuresis was measured in 5 wet nights. Then, patients were administered with 120 mcg of sublingual desmopressin. After 2 months, if there was no complete response, the dose was increased to 240 mcg. Nocturnal polyuria was defined as follows: 1.Definition 1: nocturnal urine production >130% of the expected bladder capacity (EBC). 2. Definition 2: >100% EBC. 3. Definition 3: > 20×(age + 9) mL. The primary outcome was 'response to desmopressin' after 3 months of treatment.

RESULTS

Fifty-three patients responded to desmopressin. Comparing the responses to desmopressin on the basis of the three definitions of nocturnal polyuria, no significant difference was found. There was no cutoff value of nocturnal polyuria expressed as %EBC useful in providing a significant receiver-operating characteristic (ROC) curve. The area under the ROC curve for MVV expressed as %EBC was 0.67 (95% confidence interval [CI], 0.54-0.80; p = 0.01). A MVV >103.1% of EBC had 78.8% (95% CI, 61.1-91.0) sensitivity and 47.5% (95% CI, 31.5-63.9) specificity for predicting response to desmopressin. Among the patients with nocturnal polyuria according to definition 1, a higher percentage of subjects with nocturnal polyuria in 4 out of 5 or 5 out of 5 nights responded to desmopressin, compared with other patients. Patients presenting with nocturnal polyuria according to definition 3 in 5 out of 5 nights showed a 100% of response to desmopressin. At multivariate analysis, the only significant odds ratio (OR) to respond to desmopressin was that of patients with nocturnal polyuria according to definition 1 in >3 nights (OR = 7.1, 95% CI, 1.3-40.3).

DISCUSSION AND CONCLUSIONS

The presence or absence of nocturnal polyuria-according to all three definitions-in at least one night was not effective in predicting the response to desmopressin. Predictors of desmopressin response were nocturnal polyuria in >3 out of 5 wet nights according to definition 1 and in 5 out of 5 wet nights according to definition 3.

A Pilot Study of the Normative Range of Overnight Urinary Free Cortisol Corrected for Creatinine in Children

BACKGROUND

For more than a decade, urinary free cortisol corrected for creatinine (OUFCC) has been used to assess the systemic bioactivity of inhaled corticosteroids in children with asthma. Paediatric normative ranges, however, have not been established. The aim of the present study was to define a preliminary range for OUFCC in Tanner stage 1 children.

METHODS

A post hoc analysis was performed of 26 Tanner stage one children (aged 5-11 years) with mild asthma only requiring prn (pro re nata) treatment with short-acting β₂-agonists, who participated in a 3-way cross-over knemometry study. The study comprised a run-in, two washout periods and three treatment periods (2 weeks each). Urine was collected at the end of each period. A normative range was derived using the 95% prediction interval for the geometric mean OUFCC, calculated from run-in and washout periods.

RESULTS

Twenty-six children contributed 41 OUFCC values. The geometric mean OUFCC was 9.0 nmol/mmol (95% PI: 3.6, 22.7 nmol/mmol).

CONCLUSIONS

The OUFCC preliminary normative range was 3.6 to 22.7 nmol/mmol in Tanner stage one children. A larger study in healthy children is warranted to confirm these findings and to assess potential differences in OUFCC across developmental stages and age groups, and by gender and race.

EUDRACT NUMBER

2013-004719-32, CLINICALTRIALS.

GOV IDENTIFIER

NCT02063139.

Can recording only the day-time voided volumes predict bladder capacity?

Purpose

This study aimed to demonstrate a method to easily assess bladder capacity using knowledge of day-time voided volumes, which can be obtained even from patients with nocturnal enuresis where the first morning void cannot accurately predict the bladder capacity due to bladder emptying overnight.

Materials and Methods

We evaluated 177 healthy children from 7 Korean medical centres entered the study between January 2008 and January 2009. Voided volumes measured for more than 48 hours were recorded in the frequency volume chart (FVC).

Results

Most voided volumes during day-time were showed between 30% and 80% of the maximal voided volume (MVV). The maximal voided volume during day-time (MVVDT) was significantly less than the MVV (179.5±71.1 mL vs. 227.0±79.2 mL, p<0.001). The correlation coefficients with the MVV were 0.801 for the estimated MVV using the MVVDT (MVVDT×1.25), which suggested a fairly strong relationship between the MVVDT×1.25 and the MVV.

Conclusions

The MVV derived from the FVC excluding the FMV was less than if the FMV had been included. When an accurate first morning voided volume cannot be obtained, as in patients with nocturnal enuresis, calculating MVVDT×1.25 allows estimation of the bladder capacity in place of the MVV.

Effect of traditional Chinese and Western medicine on nocturnal enuresis in children and indicators of treatment success: Randomized controlled trial

BACKGROUND

Nocturnal enuresis (NE) is a common pediatric developmental disorder. Desmopressin is frequently used for NE and is an evidence-based therapy. Suoquan capsule is a Chinese medicine commonly used for treating NE in children but is poorly understood by most scholars.

METHODS

A total of 369 children with NE were randomized to receive either suoquan, desmopressin plus suoquan, desmopressin, or behavioral intervention for 2 months, and the response rates evaluated. Subsequently, the viable demographic factors that could lead to success were investigated on logistic regression analysis. Moreover, after 3 months of follow up, the relapse rate was investigated.

RESULTS

The complete response (CR) rate in the desmopressin plus suoquan group (37.5%) was higher than that in the behavioral intervention group (6.3%, P < 0.007). The desmopressin group had a lower CR rate (22.5%) and a higher non-response rate (25.0%) than the desmopressin plus suoquan group (non-response rate, 21.9%; P > 0.007). The relapse rate in the desmopressin group was significantly higher than that in the desmopressin plus suoquan group (72.2% vs. 30.6%, P < 0.007). On Multivariate analysis, treatment group, NE frequency, and age were independent predictors of CR at 2 months (P < 0.05).

CONCLUSIONS

Combined traditional Chinese and Western treatment in children with NE is effective and has a low relapse rate. NE frequency, treatment method, and age are important predictive factors for CR after treatment.

Optimizing response to desmopressin in patients with monosymptomatic nocturnal enuresis

Most patients with monosymptomatic nocturnal enuresis can be effectively treated with an enuresis alarm or antidiuretic therapy (desmopressin), depending on the pathophysiology of the condition in the individual patient. Desmopressin is first-line therapy for enuresis caused by nocturnal polyuria, an excessive urine output during the night. However, in a recent study, around one-third of patients thought to be resistant to desmopressin were subsequently treated effectively with desmopressin monotherapy in a specialist centre. The aim of this article is to review best practice in selecting patients for desmopressin treatment, as well as outline eight recommendations for maximizing the chances of treatment success in patients receiving desmopressin. The roles of formulation, dose, timing of administration, food and fluid intake, inter-individual variation in response, body weight, adherence, withdrawal strategies and combination therapies are discussed in light of the most recent research on desmopressin and enuresis. Possible reasons for suboptimal treatment response are explored and strategies to improve outcomes in patients for whom desmopressin is an appropriate therapy are presented. Through optimization of the treatment plan in primary and specialist care centres, the hope is that fewer patients with this distressing and often embarrassing condition will experience unnecessary delays in receiving appropriate care and achieving improvements.

Evaluation of bladder capacity in children with lower urinary tract symptoms: Comparison of 48-hour frequency/volume charts and uroflowmetry measurements

INTRODUCTION

Objective evaluation of bladder capacity (BC) in children with lower urinary tract symptoms (LUTS) is important for recognizing types of bladder dysfunction. Bladder capacity is evaluated from 48-hour frequency/volume (48-h F/V) charts or by uroflowmetry with ultrasound post-void assessment. There are limited data on the reliability of both methods of assessment in children.

OBJECTIVE

The aim of the study was to compare two modalities of assessment, (F/V chart and uroflowmetry) in cohorts of children with bladder dysfunctions.

STUDY DESIGN

Maximum bladder capacity (MBC) obtained from 48-h F/V charts was compared with volumes calculated from uroflowmetry in a cohort of 86 children with different bladder dysfunctions. The BC obtained by the two modalities was compared for the three most frequent subtypes of bladder dysfunction: monosymptomatic nocturnal enuresis (MNE), overactive bladder (OAB), and dysfunctional voiding (DV). Considering a 48-h F/V chart as standard, the sensitivity, specificity, negative and positive predictive values of uroflowmetry measurements were calculated for detecting low bladder capacity.

RESULTS

The mean maximal bladder capacity (188 ± 99.42 ml) obtained from home 48-h F/V chart measurement was 17 ml lower than the mean value obtained from uroflowmetry (205 ± 112.11 ml) (P = 0.58). The differences between bladder capacities estimated by 48-h F/V chart and uroflowmetry for subjects were not significant (Figure). Concordance between 48-h F/V chart and uroflowmetry categorization of BC was present in 64 (74%) subjects. The sensitivity and specificity of uroflowmetry, in comparison with 48-h F/V chart evaluation, for recognizing low bladder capacity were 75.5% and 73.17%. The sensitivity and specificity for the different types of LUTS achieved 68.42% and 58.83% for OAB, 80% and 83% for MNE, and 50% and 83.3% for DV.

DISCUSSION

According to the International Children's Continence Society, the management of MNE in children can be made without uroflowmetry. History and MBC evaluation by 48-h F/V charts yields sufficient information. Nevertheless, in situations where F/V charts are unreliable or unavailable, uroflowmetry can be used as an alternative method. The highest discrepancy between both methods of BC evaluation was found in DV; this was mainly due to the mean PVR of 31 ml.

CONCLUSION

For children with MNE, both 48-hour frequency/volume charts and triplicate urine flow measurement with PVR evaluation are reliable methods of maximum bladder capacity evaluation. For children with OAB or DV, both methods may be necessary for accurate evaluation of decreased BC, as F/V chart and uroflow results may not be comparable.

The pathophysiology of monosymptomatic nocturnal enuresis with special emphasis on the circadian rhythm of renal physiology

Nocturnal polyuria in monosymptomatic nocturnal enuresis (MNE) has so far mainly been attributed to a disturbed circadian rhythm of renal water handling. Low vasopressin levels overnight correlate with absent maximal concentrating activity, resulting in an increased nocturnal diuresis with low urinary osmolality. Therefore, treatment with desmopressin is a rational choice. Unfortunately, 20 to 60 % of children with monosymptomatic enuresis are desmopressin-resistant. There is increasing evidence that other disturbed circadian rhythms might play a role in nocturnal polyuria. This review focuses on renal aspects in the pathophysiology of nocturnal polyuria in MNE, with special emphasis on circadian rhythms. Articles related to renal circadian rhythms and enuresis were searched through the PubMed library with the goal of providing a concise review.

CONCLUSION

Nocturnal polyuria can only partially be explained by blunted circadian rhythm of vasopressin secretion. Other alterations in the intrinsic renal circadian clock system also seem to be involved, especially in desmopressin-resistant enuresis.

WHAT IS KNOWN

• Disturbance in the circadian rhythm of arginine vasopressin secretion is related to nocturnal polyuria in children with enuresis. • Desmopressin is recommended as a treatment for monosymptomatic nocturnal enuresis, working as a vasopressin analogue acting on V2 receptors in the collecting ducts of the kidney. What is New: • Other renal circadian rhythms might play a role in nocturnal polyuria, especially in desmopressin-resistant case.

Moderate agreement between bladder capacity assessed by frequency volume charts and uroflowmetry, in adolescent and adult enuresis patients

AIMS

Frequency Volume Charts (FVC) are recommended for the evaluation of enuretic patients. Although this is a good instrument for the assessment of functional bladder capacity, it is known that patient compliance could introduce problems. Therefore, we assessed whether uroflowmetry and post-void residual volume could replace FVC recordings in specific cases, by comparing the bladder capacity as measured by FVC or uroflowmetry.

METHODS

We performed post-hoc analyses using data from a retrospective cohort study, in secondary/tertiary care. This included 907 patients between 2003 and 2013, aged ≥11 years, suffering from enuresis (≥1 wet night/fortnight). Data were collected from the medical files. Bland Altman plots were made to compare the two methods.

RESULTS

Agreement between uroflowmetry and FVC was reasonable only when uroflowmetry was between 200 and 450 ml.

CONCLUSIONS

For individual clinical purposes, uroflowmetry can be used if values are in this range. For future research, we recommend to keep measuring bladder capacity with an FVC. Neurourol. Urodynam. 36:745-747, 2017. © 2016 Wiley Periodicals, Inc.

Reference values for frequency volume chart and uroflowmetry parameters in adolescent and adult enuresis patients

AIMS

Reference values of Frequency Volume Chart (FVC) and uroflowmetry parameters for adolescent and adult enuresis patients are lacking. In this study, we aim to describe those parameters, in order to interpret findings from FVCs and uroflowmetries in those patients.

METHODS

Retrospective, descriptive cohort study, concerning 907 patients aged 11 years and older, suffering from enuresis of at least one wet night per fortnight, treated in a secondary/tertiary centre, between 2003 and 2013. The main FVC parameters of interest were: maximum voided volume (MVV), 24 hr urine production and nocturnal urine volume (NUV) including first morning void (FMV). Nocturnal polyuria (NP) was defined based on both International Children's Continence Society (ICCS, 2014) and International Continence Society (ICS, 2002) definitions. Data of all patients were collected from the medical files.

RESULTS

Age had an impact on diurnal and nocturnal FVC parameters. Median MVV excluding FMV was 250 ml in the youngest, 11-year-old males and 363 ml in the eldest, ≥18-yr-old males. For females, these values were 230 ml and 310 ml. Median 24 hr urine production increased from 1,025 ml to 1,502 ml (males) and from 1,007 ml to 1,557 ml (females). Median NUV showed an increase from 387 ml to 519 ml (males) and from 393 ml to 525 (females). Forty-two percent of men and 30% of women had a small MVV (for age). Prevalence of NP differed when assessed by the ICS or the ICCS definition: following ICS guidelines, NP was present in 96% of our male and 93% of our female population, compared to 27% and 41%, respectively, following ICCS guidelines.

CONCLUSIONS

Both small MVV and NP were found frequently in our adolescent and adult enuresis patients, which is in line with the current thoughts on causal factors. NP prevalence is quite different when using ICS or ICCS definitions, respectively. We would like to encourage the development of an unambiguous definition of NP to use both in pediatric and adult urology. Neurourol. Urodynam. 36:463-468, 2017. © 2016 Wiley Periodicals, Inc.

Neuropsychological functioning related to specific characteristics of nocturnal enuresis

INTRODUCTION/BACKGROUND

There is a high comorbidity demonstrated in the literature between nocturnal enuresis and several neuropsychological dysfunctions, with special emphasis on attention deficit hyperactivity disorder (ADHD). However, the majority of the psychological studies did not include full non-invasive screening and failed to differentiate between monosymptomatic nocturnal enuresis (MNE) and non-MNE patients.

OBJECTIVE

The present study primarily aimed to investigate the association between nocturnal enuresis and (neuro)psychological functioning in a selective homogeneous patient group, namely: children with MNE and associated nocturnal polyuria (NP). Secondly, the study investigated the association between specific characteristics of nocturnal enuresis (maximum voided volume, number of wet nights and number of nights with NP) and ADHD-inattentive symptoms, executive functioning and quality of life.

STUDY DESIGN

The psychological measurements were multi-informant (parents, children and teachers) and multi-method (questionnaires, clinical interviews and neuropsychological testing).

RESULTS

Thirty children aged 6-16 years (mean 10.43 years, SD 3.08) were included. Of them, 80% had at least one psychological, motor or neurological difficulty. The comorbid diagnosis of ADHD, especially the predominantly inattentive presentation, was most common. According to the teachers, a low maximum voided volume (corrected for age) was associated with more attention problems, and a high number of nights with NP was associated with more behaviour-regulation problems. No significant correlations were found between specific characteristics of enuresis and quality of life. Details are demonstrated in Table.

DISCUSSION

The children were recruited from a tertiary referral centre, which resulted in selection bias. Moreover, NP was defined as a urine output exceeding 100% of the expected bladder capacity for age (EBC), and not according to the expert-opinion-based International Children's Continence Society norm of 130% of EBC. The definition for NP of a urine output exceeding 100% of the EBC is more in line with the recent findings of the Aarhus group.

CONCLUSIONS

For children with MNE and associated NP, a high comorbidity with the predominantly inattentive presentation of ADHD was demonstrated. Children experienced problems with daytime functioning in relation to their wetting problem at night. According to the teachers, a low maximum voided volume was associated with more attention problems, and a high number of nights with NP was associated with more behaviour-regulation problems. Although comorbidity is still the appropriate word to use, the observation favours a more complex pathogenesis of enuresis with a common pathway in the central nervous system, including: neurotransmitters, influencing neuropsychological functioning as well as sleep, circadian rhythm of diuresis and bladder function control.

Predictive parameters of response to desmopressin in primary nocturnal enuresis

INTRODUCTION/BACKGROUND

Many recent treatment guidelines have advocated the importance of a full noninvasive medical evaluation. To individualize treatment, special emphasis must be put on recording of the maximum voided volume (MVV) and nocturnal diuresis in a diary or frequency/volume chart.

OBJECTIVE

The aim of this study was to identify any possible predictive factors to desmopressin response.

STUDY DESIGN

This study is a re-analysis of a prospective, open-label, multinational, phase-IV study evaluating ≤6 months of treatment with desmopressin tablets for children with primary nocturnal enuresis. The children were enrolled between April 2002 and December 2004 from 86 centers in four countries: UK, Canada, Germany and France. A total of 936 children were screened; 744 children aged 5-15 years participated in the study. Of these, 471 children completed the study with 6 months follow-up and recording in a frequency/volume chart. All children experienced six or more wet nights during the 14-day screening period. Exclusion criteria were: organic pathology, treatment for enuresis within the past year, previous treatment for enuresis for >4 weeks, diurnal symptoms, renal or central diabetes insipidus and the use of systemic antibiotics or other drugs known to affect desmopressin activity. The predictive value of number of wet nights a week, fluid intake, daytime voiding frequency and diuresis was investigated by performing a multinomial logistic regression.

RESULTS

Of the demographic variables, age was the only significant predictor for response to desmopressin. Controlling for age, the significant predictive variables were: number of wet nights a week, average voided volume daytime, maximum voided volume daytime, total daytime diuresis, nocturnal diuresis (see Figure), maximum voided volume 24 h and total 24 h diuresis. More than 80% of the children had no nocturnal polyuria and a low maximum voided volume.

DISCUSSION

Performing a secondary analysis is a limitation because the original study was not designed for that. A new prospective study is ethically hardly defendable for children if data are available from previous literature [1]; therefore, a re-analysis was the appropriate choice. The study confirms the predictive value of age, number of wet nights a week and nocturnal diuresis [1,2].

CONCLUSIONS

The study demonstrates that desmopressin response rates are higher in children with greater age, limited number of wet nights a week and nocturnal polyuria. Only a minority of a primary nocturnal enuresis population, based on history alone, had nocturnal polyuria. The majority had a low maximum voided volume. The results clearly stress the importance of a frequency/volume chart for individualizing therapy to the characteristics, thereby resulting in elevated success rates. Registration number of clinical trial: Clinical Trials.gov NCT00245479.

Periodic limb movements during sleep are associated with a lower quality of life in children with monosymptomatic nocturnal enuresis

The study investigates whether cortical arousals and periodic limb movements during sleep are related to daytime psychological functioning in children with monosymptomatic nocturnal enuresis with associated nocturnal polyuria. Psychological functioning is evaluated on five domains: attention deficit hyperactivity disorder-inattentive problems, quality of life, internalizing problems, externalizing problems, and executive functioning. This multi-informant (parents, teachers, and children) and multi-method study included overnight video-polysomnography, questionnaires, and neuropsychological testing. Thirty children (7 girls) 6 to 16 years (mean 10.43 years, SD 3.08) were selected in a tertiary enuresis center. A high index of periodic limb movements during sleep was associated with a lower quality of life, according to the child. No significant correlations were found with attention deficit hyperactivity disorder-inattentive problems, internalizing problems, externalizing problems, and executive functioning.

CONCLUSION

This study clarifies the relationship between sleep parameters and psychological functioning of the children with monosymptomatic nocturnal enuresis and associated nocturnal polyuria according to the child, the parents, and the teachers. Periodic limb movements during sleep are associated with a lower quality of life of the child.

The standardization of terminology of lower urinary tract function in children and adolescents: Update report from the standardization committee of the International Children's Continence Society

AIM

The impact of the original International Children's Continence Society (ICCS) terminology document on lower urinary tract (LUT) function resulted in the global establishment of uniformity and clarity in the characterization of LUT function and dysfunction in children across multiple healthcare disciplines. The present document serves as a stand-alone terminology update reflecting refinement and current advancement of knowledge on pediatric LUT function.

METHODS

A variety of worldwide experts from multiple disciplines within the ICCS leadership who care for children with LUT dysfunction were assembled as part of the standardization committee. A critical review of the previous ICCS terminology document and the current literature was performed. Additionally, contributions and feedback from the multidisciplinary ICCS membership were solicited.

RESULTS

Following a review of the literature over the last 7 years, the ICCS experts assembled a new terminology document reflecting current understanding of bladder function and LUT dysfunction in children using the resources from the literature review, expert opinion and ICCS member feedback.

CONCLUSIONS

The present ICCS terminology document provides a current and consensus update to the evolving terminology and understanding of LUT function in children. Neurourol. Urodynam. 35:471-481, 2016. © 2015 Wiley Periodicals, Inc.

Are we accurately predicting bladder capacity in infants?

INTRODUCTION

Estimating bladder capacity is an important component in the evaluation of many urological disorders. For estimates to be of clinical value, precise reference ranges are needed. While accepted reference ranges have been established in adults and older children, none have been validated in infants. We endeavour to determine the normal bladder capacity of children less than 1 year of age.

METHODS

We retrospectively reviewed the charts of children aged 0 to 12 months with cutaneous stigmata of spinal dysraphism who were referred to the urology clinic to rule out tethered cord between October 2004 and July 2011. Patients with normal urologic assessment, who did not have surgery during the time they were followed, were included in the study cohort. Urodynamic studies were performed using the Laborie Medical Technologies UDS-600. Bladder filling occurred via a catheter at a rate of 10% of the expected total bladder capacity/minute. Bladder capacity was defined as the volume of filling when the child voided around the catheter. We collected data, including age at urodynamics, bladder capacity, detrusor pressure at capacity, bladder compliance and length of follow-up.

RESULT

In total, 46% (84/183) of patients had a normal urologic assessment and met the inclusion criteria. The median age was 9.0 months (interquartile range [IQR] 6.8-11.0). The average bladder capacity was 48.9 mL (standard deviation [SD] 32.8) and the mean detrusor pressure at capacity was 8.5 cmH2O (SD 10.0). Mean compliance was 14.1 mL/cmH2O (SD 13.6). The average length of follow-up was 40.7 months (SD 26.2) and during this interval no patients were found to have urologic or neurologic abnormalities and none underwent tethered cord release.

CONCLUSION

Bladder capacity in infants with a median age of 9.0 months was found to be 48.9 mL. This is less than half of the volume predicted by a commonly employed formula. A novel method of estimating bladder capacity in infants is required.

Evaluation of nocturnal bladder capacity and nocturnal urine volume in nocturnal enuresis

OBJECTIVE

To investigate the diagnostic accuracies of maximum voided volume (MVV) and first morning urine osmolality and compare these with accuracies of nocturnal bladder capacity (NBC) and nocturnal urine volume, respectively, in children with nocturnal enuresis.

MATERIALS AND METHODS

A total of 70 children with nocturnal enuresis were assessed (mean age 7.1 ± 2.2 years). Baseline parameters were obtained by measuring MVV using a voiding diary, first morning urine osmolality on a wetting day, diaper weight by checking twice per night and first morning urine volume.

RESULTS

The proportions of small NBC and small MVV were 34.3% (24 cases) and 55.7% (39 cases), respectively. The proportions of low osmolality of first morning urine and nocturnal polyuria (NP) were 45.7% (32 cases) and 25.7% (18 cases), respectively. The sensitivity and specificity of small MVV for small NBC were 53.8% and 90.3%, respectively; the sensitivity and specificity of first morning urine osmolality for NP were 33.3% and 50.0%, respectively.

CONCLUSIONS

The diagnostic accuracies of MVV and urine osmolality for small NBC and NP were only modest to low.