SOME NEW INSIGHTS INTO BLADDER FUNCTION IN INFANCY

Objectives To evaluate normal bladder function and micturition pattern s in infants. Patients, subjects and methods Twenty-one infants (16 bo ys, five girls; mean age 5.9 months) with no lower urinary tract patho logy underwent natural filling cystometry. Micturition patterns were a lso observed simultaneously with polysomnography in 26 healthy neonate s (16 boys, 10 girls; mean age 7.4 days). Results In infants, cystomet ry showed (95% CI) a capacity of 42-53 mt, a maximum rise in detrusor pressure during voiding of 95-120cmH(2)O and a voiding efficiency (voi ded volume/capacity) of 0.86-0.91. On micturition, urinary flow was di scoordinated from peak detrusor pressures in 10 infants, Detrusor inst ability occurred in one of 21 infants, Micturition was observed only d uring wakefulness or on arousal from sleep. In neonates, 17 of 61 reco rded voids (28%) were during full wakefulness and 44 (72%) during arou sal from sleep. Notably, none of the recorded voids occurred during qu iet sleep. Conclusions The normal infant's bladder was stable and empt ied almost completely, Voiding with incomplete co-ordination between d etrusor contraction and urinary sphincter relaxation could be normal, Micturition never occurred during quiet sleep. There was cortical arou sal in response to a full bladder even in new-born infants. This contr adicts the traditional concept of a totally uninhibited bladder in inf ancy, There are potential implications for the management of children with nocturnal enuresis.