Functional bladder capacity as predictor of response to desmopressin and retention control training in monosymptomatic nocturnal enuresis

OBJECTIVE: To evaluate the efficacy of intranasal desmopressin (DDAVP) and retention control training (RCT) for monosymptomatic nocturnal enuresis in childhood and to assess the predictive value of daytime functional bladder capacity for both methods. MATERIALS AND METHODS: A total of 114 children with monosymptomatic nocturnal enuresis, of whom 99 (86.8%) wetted the bed every night, were treated with 1 of the 2 methods: intranasal DDAVP in 54 and RCT in 60 subjects. RESULTS: Twenty-one of 54 patients (38.9%) and 14 of 60 patients (23.3%) in the DDAVP group and the RCT group, respectively, achieved strong improvement (p = 0.061). Forty-five of 54 (90.0%) in the DDAVP and 35 of 60 (58.3%) in the RCT group had a more than 50% decrease in wet nights (p = 0.004). In the DDAVP group, the functional bladder capacities at baseline in responders and nonresponders were 82+/-22% and 56+/-20% of the predicted bladder capacity for their age (p<0.001). In the RCT group, responders and nonresponders did not differ in functional bladder capacity at baseline. CONCLUSION: DDAVP treatment is more effective than RCT in decreasing the number of wet nights in childhood nocturnal enuresis, but not so effective in children with a low functional bladder capacity. Daytime functional bladder capacity is a valuable predictor of response to DDAVP, but not so to RCT.