PURPOSE: We evaluated bladder reservoir function in children with monosymptomatic nocturnal enuresis with and without response to desmopressin, and assessed the importance of first morning voiding when defining maximum voided volume. MATERIALS AND METHODS: A total of 238 patients 5 to 15 years old with monosymptomatic nocturnal enuresis completed 2 weeks of enuresis recordings and 4 days of frequency-volume charts. Of the patients 186 completed subsequent home recordings during titration with desmopressin. Maximum voided volumes with and without the first morning void were calculated. Desmopressin response was defined as greater than 50% reduction in wet nights. Maximum voided volume with and without first morning voiding was evaluated as a prognostic factor for desmopressin response. RESULTS: Mean ± SD maximum voided volume without first morning void was comparable between desmopressin responders and nonresponders (230.5 ± 69.3 ml and 219.0 ± 84.8 ml, respectively, p = 0.391). Inclusion of the first morning void demonstrated responders to have significantly larger values than nonresponders (mean ± SD 296.0 ± 94.0 ml vs 233.5 ± 90.0 ml, p <0.001). When first morning void was included, desmopressin response was seen in 40% of patients with voided volumes of 65% expected volume for age vs 10% of patients with volumes less than 65% expected volume for age. CONCLUSIONS: Maximum voided volume can be used as a predictor of desmopressin response only if first morning voids are taken into consideration. All patients with monosymptomatic nocturnal enuresis should receive clear instructions to include this measure when completing frequency-volume charts.

OBJECTIVE: To investigate why not all children with monosymptomatic nocturnal enuresis (MNE) treated with desmopressin give an adequate response. MATERIALS AND METHODS: We included 114 children with MNE aged 5-15 years (9.8 ± 0.2 years) who experienced at least 1 wet night and more than 2 dry nights during desmopressin treatment. The patients made home recordings for 2 weeks as baseline and for 2-4 weeks of desmopressin titration. Nocturnal urine production during wet and dry nights, and maximum voided volumes (MVVs) were documented in all patients. RESULTS: Sixty-four patients were desmopressin non-responders, 29 were either partial responders or responders, while 21 patients were full responders. Desmopressin reduced nocturnal urine production dramatically during dry nights compared with pre-treatment wet nights. Nocturnal urine production during desmopressin treatment was significantly greater during wet nights compared to dry nights (243 ± 9.32 vs 176 ± 5.31 ml, P < 0.001). There was a highly significant correlation between individual nocturnal urine output and MVV, and dry nights were characterized by nocturnal urine output/MVV ratios well below 1.0. CONCLUSION: The anti-enuretic response to desmopressin seems to be dependent upon the degree of reduction in nocturnal urine production. Research on desmopressin bioavailability in children is needed.

HASH(0x2b8f7c8987d0)

The transition from wakefulness to sleep is associated with a pronounced decline in diuresis, a necessary physiological process that allows uninterrupted sleep. The aim of this study was to assess the effect of acute sleep deprivation (SD) on urine output and renal water, sodium, and solute handling in healthy young volunteers. Twenty young adults (10 male) were recruited for two 24-h studies under standardized dietary conditions. During one of the two admissions, subjects were deprived of sleep. Urine output, electrolyte excretions, and osmolar excretions were calculated. Activated renin, angiotensin II, aldosterone, arginine vasopressin, and atrial natriuretic peptide were measured in plasma, whereas prostaglandin E(2) and melatonin were measured in urine. SD markedly increased the diuresis and led to excess renal sodium excretion. The effect was more pronounced in men who shared significantly higher diuresis levels during SD compared with women. Renal water handling and arginine vasopressin levels remained unaltered during SD, but the circadian rhythm of the hormones of the renin-angiotensin-aldosterone system was significantly affected. Urinary melatonin and prostaglandin E(2) excretion levels were comparable between SD and baseline night. Hemodynamic changes were characterized by the attenuation of nocturnal blood pressure dipping and an increase in creatinine clearance. Acute deprivation of sleep induces natriuresis and osmotic diuresis, leading to excess nocturnal urine production, especially in men. Hemodynamic changes during SD may, through renal and hormonal processes, be responsible for these observations. Sleep architecture disturbances should be considered in clinical settings with nocturnal polyuria such as enuresis in children and nocturia in adults.

PURPOSE: We determined normal, age related reference data regarding maximum voided volume and nocturnal urine production using the same methodology as in clinical practice. MATERIALS AND METHODS: A total of 62 girls and 86 boys without enuresis (mean +/- SD age 9.64 +/- 2.63 years, range 3 to 15) completed 4 days (2 weekends) of frequency-volume charts and 14 days of home recording of nocturnal urine production. From these recordings maximum voided volume with and without first morning void was derived for each subject. Also, average nocturnal urine volume with and without nocturia was calculated. Percentiles were produced by dividing the population into 1-year age groups. RESULTS: Based on 2,836 daytime voids and 1,977 overnight recordings, maximum voided volume and nocturnal urine volume showed a significant linear relationship with age but not with gender. Maximum voided volume with first morning void was significantly higher than without (403 +/- 137 ml vs 281 +/- 112 ml, p <0.0001) and the 50th percentile line of maximum voided volume with first morning void was 80 to 100 ml higher than Koff's formula (30 x [age + 1] ml). Conversely the 50th percentile of maximum voided volume without first morning void was almost identical to Koff's formula. Regarding nocturnal measurements, nocturia was noted on 128 nights (6.5%) and nocturnal urine volume on nights with nocturia was significantly higher than on nights without nocturia (365 +/- 160 ml vs 248 +/- 75 ml, respectively, p <0.0001). The 97.5th nocturnal urine volume percentile line of healthy children deviated markedly from the current International Children's Continence Society definition of nocturnal polyuria, especially at low and high ages. CONCLUSIONS: We demonstrate clearly that the universally used formula 30 x (age + 1) ml is indeed valid for a population of healthy Danish children but only if the first morning void is disregarded. Furthermore, we question the validity of the current International Children's Continence Society formula for nocturnal polyuria (nocturnal urine volume greater than 130% of maximum voided volume for age), and instead we propose the formula, nocturnal urine volume greater than 20 x (age + 9) ml.

PURPOSE: We studied the effect of transcutaneous electrical nerve stimulation in children with overactive bladder and treatment refractory daytime urinary incontinence. MATERIALS AND METHODS: We recruited 27 children 5 to 14 years old with daytime urge incontinence refractory to timer assisted standard urotherapy and anticholinergics who had normal urinalysis, and unremarkable urinary tract ultrasound and physical examination. Study exclusion criteria were bladder underactivity, lower urinary tract obstruction, ongoing defecation disorders, lower urinary tract surgery and previous transcutaneous electrical nerve stimulation. After a 2-week run-in of standard urotherapy the children underwent natural fill ambulatory urodynamics to confirm detrusor overactivity. Subsequently they were randomly allocated to 4 weeks of 2 hours of daily active or placebo S2-S3 transcutaneous electrical nerve stimulation. The severity of incontinence and urgency, and 48-hour bladder diaries were recorded before randomization and during intervention week 4. Children withdrew from anticholinergics throughout the study period. RESULTS: Two children were excluded from randomization due to urodynamic signs of lower urinary tract obstruction. After 4 weeks of intervention 8 children (61%) in the active group showed a significant decrease in incontinence severity but this occurred in only 2 (17%) in the sham treated group (p <0.05). The active group had a significantly greater decrease in daily incontinence episodes compared to the sham treated group (p <0.01). Transcutaneous electrical nerve stimulation did not alter maximal and average voided volumes. CONCLUSIONS: Sacral transcutaneous electrical nerve stimulation seems superior to placebo for refractory daytime incontinence in children with overactive bladder. This effect does not seem to be a consequence of improved bladder reservoir function.

PURPOSE: We describe prolonged rectal manometry used to characterize rectal motor activity patterns and possible rectum-bladder interaction during defecation and micturition in children with nonneuropathic overactive bladder. MATERIALS AND METHODS: We evaluated 10 children with a mean +/- SD age of 9.7 +/- 1.3 years with overactive bladder who underwent urodynamics and 24-hour rectal manometric recording. All records were analyzed visually. Rectal contractions were defined as pressure runs exceeding 5 cm H(2)O and lasting longer than 5 seconds. RESULTS: Three rectal motility patterns were noted in all children, including 1) slow tonic pressure waves with a frequency of 3 to 12 per hour, b) rectal motor complexes with a frequency of 3 to 10 per minute and c) single contractions 10 to 30 seconds in duration. The median nocturnal duration of rectal motor complexes was longer than that during the day (16.3 minutes, range 10.8 to 18.8 vs 11.0, range 8.9 to 12.6, p <0.05). As a percent of time, median total contraction time was greater at night than during the day (51.9%, range 42.6% to 56.9% vs 30.6%, range 19.4% to 49.3%, p <0.05). Characteristic rectal activity was seen during defecation and voiding but no bladder-rectum interaction was detected. CONCLUSIONS: We identified 3 rectal motility patterns in all children with overactive bladder. Like the upper gastrointestinal tract, the rectum shows some periodic motor activity, which is more frequent at night. No association was observed between bladder and rectal activity during micturition and defecation.

Objective. To analyse retrospectively the efficacy of day-time incontinence treatment in a secondary referral centre and consider characteristics of responders to the different therapeutic interventions. Material and methods. All children treated for day-time urinary incontinence at the authors' clinics from 2000 to 2004 were included. Children with ongoing urinary tract infections were excluded. Before treatment, children filled out registrations of incontinence episodes and 48 h frequency-volume charts. Faecal disorders were treated before urinary incontinence. All children were subjected to standard urotherapy and were secondarily recommended a timer-watch. If standard urotherapy had no effect, anticholinergics were added. Results. The study included 240 children with day-time urinary incontinence. Of these, 45 had faecal problems and 17% obtained urinary continence when these were successfully treated. In total, 126 (55%) became dry on standard urotherapy. Of the 60 children who had a timer-watch in addition to standard urotherapy, 70% became dry. Of the 62 children who had anticholinergics in addition to standard urotherapy, 81% became continent. Fifteen (6%) did not achieve continence and another 11 patients were lost to follow-up. Children who became dry solely on standard urotherapy had a significantly lower voiding frequency (p<0.05), larger voided volumes as a percentage of those expected for age (p<0.01) and fewer incontinence episodes per week (p<0.05) than children needing anticholinergics. Conclusions. Most children achieve day-time continence solely on standard urotherapy. Children who need anticholinergics to achieve dryness seem to be those with more severe bladder reservoir function abnormalities and symptoms.

PURPOSE: Daytime voiding frequency is an important criterion in the classification of childhood incontinence. The aim of this study was to assess the relative impact of diuresis and bladder capacity on voiding frequency. MATERIALS AND METHODS: We analyzed data from 570 children 4 to 15 years old (median age 8.3 +/- 2.0 years) treated for urinary incontinence at a secondary referral center, and 87 healthy controls. Based on frequency-volume charts, daytime voiding frequency, age adjusted maximum voided volume, daytime diuresis and fluid intake were calculated. Children were classified according to voiding frequency into 3 groups-decreased (fewer than 3 voids daily), normal (3 to 7) and increased voiding frequency (more than 7). RESULTS: A total of 219 children had monosymptomatic enuresis, while 351 children presented with daytime symptoms. In children with daytime symptoms we found a significant difference between voiding frequency groups regarding daytime diuresis (decreased voiding frequency 12.3 +/- 4.1 ml/kg, normal 18.7 +/- 6.0 ml/kg, increased 31.1 +/- 9.8 ml/kg, p <0.001). In contrast, maximum voided volume observed/expected bladder capacity for age did not differ significantly between normal and increased frequency groups (72%+/- 25% vs 74%+/- 23%), compared to patients with decreased voiding frequency (89%+/- 30%, p <0.01). Also, in healthy children we found a positive correlation between voiding frequency and daytime diuresis, whereas maximum voided volume observed/expected bladder capacity for age did not correlate with voiding frequency. Furthermore, we observed a significant positive correlation between fluid intake and diuresis (r = 0.53, p <0.001). CONCLUSIONS: In healthy controls and children with incontinence daytime voiding frequency depends mainly on diuresis, and seems less influenced by bladder capacity. Diuresis should be taken into consideration when evaluating voiding frequency from frequency-volume charts in children.

PURPOSE: We tested whether transverse rectal diameter measured by ultrasound could identify rectal impaction, investigated whether transverse diameter is enlarged in constipated children compared to healthy children and evaluated transverse diameter during treatment of constipation. MATERIALS AND METHODS: A total of 51 children 4 to 12 years old were included in the study. Of the children 27 (mean age 7.0 +/- 1.8 years) had been diagnosed with chronic constipation by Rome III criteria and 24 (9.1 +/- 2.7 years) were healthy controls. All patients underwent a thorough medical history and physical examination, including digital rectal examination and measurement of rectal diameter by transabdominal ultrasound. Constipated children underwent repeat investigations after 4 weeks of laxative treatment. RESULTS: Average rectal diameter of children with negative digital rectal examination was 21 +/- 4.2 mm (mean +/- SD), leading to the approximation that a value greater than 29.4 mm (mean +/- 2 SD) indicates rectal impaction. All children with rectal impaction identified by digital examination had a rectal diameter larger than 29.4 mm. Moreover, constipated children had a significantly larger rectal diameter (42.1 +/- 15.4 mm) than healthy children (21.4 +/- 6.0 mm, p <0.001). After 4 weeks of laxative treatment constipated children had a significant reduction in rectal diameter (mean 26.9 +/- 5.6 mm, p <0.001). CONCLUSIONS: Transverse rectal diameter seems to be a valuable tool to identify rectal impaction and may replace digital rectal examination. Constipated children have a significantly larger rectal diameter compared to healthy children, and when constipation is treated the diameter is reduced significantly.