32nd ESPU Congress in Ghent, Belgium

S18: ENURESIS

Moderators: Simona Gerocarni Nappo (Italy), Erik Van Laecke (Belgium)

ESPU Meeting on Saturday 11, June 2022, 08:00 - 08:30


08:00 - 08:03
S18-1 (OP)

A SINGLE-CENTER PROSPECTIVE COHORT STUDY ON FIRST-MORNING URINE OSMOLALITY AND NOCTURNAL ENURESIS IN CHILDREN

Jae Min CHUNG and Sang Don LEE
Pusan National Children's Hospital, Urology, Yangsan-Si, REPUBLIC OF KOREA

PURPOSE

To investigate the response rate of treatment of nocturnal enuresis according to first-morning urine osmolality before treatment.

MATERIAL AND METHODS

We assessed a total of 99 children with nocturnal enuresis (mean age, 86.5±25.2 months). Patients were divided into two groups according to the level of first-morning urine osmolality: (1) High osmolality group: more than 800 mosm/kg (61 cases, 61.6%), and (2) Low osmolality group: less than 800 mosm/kg (38 cases, 38.4%). Baseline parameters were obtained from frequency volume charts for at least 2 days, UFM with PVR and a questionnaire for the presence of frequency, urgency, and urinary incontinence. All patients were primarily treated with standard urotherapy and pharmacological treatment. The response rate was analyzed usually at 1 month and 3 months after initiation of medication.

RESULTS

The first-morning urine osmolality showed a statistically significant differences with 997.1±119.6 mosm/kg in high group and 600.9±155.9 mosm/kg in low group (p<0.001). The first-morning bladder capacity (p=0.021) and total urine volume (p=0.019) showed a significant differences, which were larger and more in Low group. And the response rate in low group was also higher, at 1 month 25.6% vs 45.1% (p=0.012) and at 3 months 36.9% vs 63.2% (p<0.001).

CONCLUSIONS

The children with nocturnal enuresis that has the lower first-morning urine osmolality showed the better response rate for treatment. Further study with larger patient numbers was needed to define the etiology.


08:03 - 08:06
S18-2 (OP)

CIRCADIAN RHYTHM OF URINARY WATER AND SOLUTE EXCRETION IN CHILDREN WITH ENURESIS

Sevasti KARAMARIA 1, Vincent DELENS 2, Lien DOSSCHE 1, Ann RAES 1, Evelien SNAUWAERT 3 and Johan VANDE WALLE 1
1) Ghent University Hospital, Ghent University, Pediatric Nephrology, Ghent, BELGIUM - 2) Ghent University, Ghent, BELGIUM - 3) Ghent University Hospital, Pediatric Nephrology, Ghent, BELGIUM

PURPOSE

Background

Enuresis is caused by nocturnal urine production and functional bladder capacity mismatch. ICCS defines nocturnal polyuria (NP) as nocturnal diuresis (ND) >130% of Expected Bladder Capacity (EBC). It is well documented as a pathogenetic mechanism in monosymptomatic, but little is known of its incidence/characteristics in non-monosymptomatic enuresis. NP is attributed to the abnormal circadian rhythm of vasopressin (AVP). However, 40-60% of patients treated with desmopressin show insufficient response, suggesting other factors like nutrition and circadian rhythm of other renal functions may be involved.

Aim: study the circadian rhythm on water and solute excretion in fractionated urine samples over 24h (4-day and 4-night samples)

MATERIAL AND METHODS

Methods: retrospective analysis of 403 children divided in 3 groups a) low-normal ND (<100% EBC, n=171) b) high-normal ND (≤100-129% EBC, n=93) c) NP (≥130% EBC, n=139).

RESULTS

NP and high-normal ND groups demonstrate an increased diuresis rate overnight and an abnormal circadian rhythm of diuresis (p=0,001) and osmolar excretion (p<0,001), predominantly in the two first nighttime samples. Children with NP produced more urine (p<0,003) and excreted more osmols (p<0,001) overnight but also at daytime and in a 24h-period. 

CONCLUSIONS

Our data suggest that NP is better defined as ND>100% EBC; this population might be equally desmopressin responsive. Pathogenesis is more complex than an abnormal AVP circadian rhythm: in 60% of patients, abnormalities of other renal circadian rhythms and/or increased nutritional intake might be involved. ND is the highest and osmolality the lowest early in the night; treatment should rather target a fast action


08:06 - 08:09
S18-3 (OP)

THERAPEUTIC WINDOW FOR DESMOPRESSIN IN NOCTUNAL ENURESIS

Sevasti KARAMARIA 1, Lien DOSSCHE 1, Ann RAES 1, Evelien SNAUWAERT 2 and Johan VANDE WALLE 1
1) Ghent University Hospital, Ghent University, Pediatric Nephrology, Ghent, BELGIUM - 2) Ghent University Hospital, Pediatric Nephrology, Ghent, BELGIUM

PURPOSE

ICCS suggests classifying enuresis into MNE and NMNE, where MNE is likely to respond to desmopressin and/or alarm. This led to the misconception that NMNE could not benefit from desmopressin. With the recent ICCS standardization, most patients are now labeled NMNE, many of them having LUTSandnocturnal polyuria. Desmopressin’s renal concentrating response has no direct correlation with bladder dysfunction and should be evaluated independently.

Aim: identify patients who might benefit from desmopressin (defined as urinary osmolality (Uosmol)<850 mOsm/l) and study the timing overnight. 

MATERIAL AND METHODS

Methods: retrospective analysis of 398 enuretic children who performed a 24h-urine concentration profile at home (4 daytime (D1-D4), 4 nighttime collections (N1-N4)).

RESULTS

212 children (>50%) had Uosmol<850 mOsm/l at the 1st-night collection (N1) and could benefit from a short-term desmopressin activity. In a significant percentage, Uosmol is low later in the night (181 N2, 169 N3, 167 N4), needing a longer action. 50 patients didn’t reach Uosmol>850mOsm/l over 24h, suggesting lower maximal renal concentration capacity of the normal spectrum or high 24h fluid intake. 

CONCLUSIONS

Classifying enuresis is mainly bladder/LUTS driven and is widely accepted to predict the effect of therapy. However, many patients have a combination of LUTS and abnormal circadian diuresis pattern. Desmopressin’s anti-diuretic effect may be expected in most patients with high diuresis and low Uosmol. >50% of patients have a low Uosmol early in the night, hence a therapeutic window for desmopressin. In 1/3 patients, Uosmol remains low longer, needing longer-acting V2-stimulation. Desmopressin’s PK/PD characteristics don’t fulfill these promises.


08:09 - 08:30
Discussion