Long-term home studies of water balance in patients with nocturnal enuresis

A 2-week, home-based study was conducted on 75 children with nocturnal enuresis to monitor the frequency of enuretic episodes and the volume of nocturnal urine production. The objectives of the study were to correlate nocturnal urine production to the occurrence of nocturnal enuresis and response to desmopressin (Minirin, DDAVP) treatment. Furthermore, patient compliance was evaluated. Enuresis episodes and nocturnal urine production was recorded every night during two base-line weeks without treatment and during 2 weeks with 20-40 micrograms desmopressin at bedtime. During both periods fluid intake and micturition volumes were recorded for 2 days. Desmopressin response was defined as > 50% reduction in wet nights during treatment. It was found that patient compliance was acceptable in most patients. Regarding urine output it was found that base-line nocturnal urine production was significantly higher during nights when enuresis occurred than during "dry" nights and significantly higher in desmopressin responders compared with desmopressin non-responders. During treatment with desmopressin, nocturnal urine production in desmopressin responders decreased to levels similar to those of non-responders. The results confirm inpatient circadian studies of urine output and emphasise the importance of nocturnal polyuria in patients with monosymptomatic enuresis. The response to desmopressin was found to correlate with the occurrence of nocturnal polyuria. Home studies were considered to be a useful tool in the characterisation of patients with nocturnal enuresis.