Bladder reservoir reduced during sleep in nocturnal enuresis
Wet nights appear to occur with considerable frequency in children with monosymptomatic nocturnal enuresis (MNE) and normal maximal voided volumes (MVV), with a nocturnal urine production well below their MWV and even <65 percent of estimated bladder capacity, according to a study.
The study included 103 children aged 5 to 15 years who were treated for MNE and had normal MVV on daytime frequency volume charts. Home recordings were completed for 2 weeks at baseline and during desmopressin dose titration.
Estimated nocturnal bladder capacity, on the other hand, was evaluated separately each night as the total nocturnal urine production causing a wet night. Estimated nocturnal bladder capacity was considered reduced if nocturnal urine production during the night was less than the MVV.
Of the children, 84 (82 percent) had at least one wet night. In this group, nocturnal urine production below the daytime MVV was indicative of a reduced estimated nocturnal bladder capacity. Mean percentage of wet nights with reduced estimated nocturnal bladder capacity was 49 percent. Response to desmopressin was reported in a total of 11 percent.
In the group of paediatric patients with frequently reduced nocturnal bladder capacity, 91 percent experienced wet nights, with nocturnal urine production <65 percent of expected bladder capacity.
The present data suggest that bladder reservoir dysfunction during sleep is relatively common in MNE, researchers said. As this abnormality may not be reflected on daytime recordings, night-time data with nocturnal urine must be collected.
Bladder reservoir dysfunction during sleep potentially explains treatment failure to desmopressin despite adequate antidiuretic response, researchers added.