Introduction
Bladder dysfunction and urinary incontinence encompass some of the most common chronic diseases in children. Bladder dysfunction and incontinence have major impact on their quality of life, especially their self-esteem. It is also associated with potential morbidity including urinary tract infections and constipation. Assessment and treatment are therefore recommended for children with daily incontinence after the age of 3 to 4 years when the majority of children have developed urinary control and are dry during the day. Night-time bladder control is expected a little later, about the age of 5 years. Normal voiding frequency for children is 4-7 voids per day. Deviations from the normal cycle of bladder filling and emptying constitute storage and voiding disorders.
Symptoms
Incontinence is defined as any involuntary loss of urine. Urinary incontinence in pediatric patients may be related to a congenital anatomic or neurologic abnormality such as bladder exstrophy or myelomeningocele, However, in many cases, there is no obvious cause and the term ‘functional incontinence’ is used.
When urinary incontinence occurs during the night it is termed nocturnal enuresis. It is considered to be primary nocturnal enuresis if the child has never been dry at night for at least six months and it is considered to be secondary nocturnal enuresis if the child has had a prior dry interval of 6 months of longer at night. Enuresis is described as monosymptomatic in children without any other type of voiding dysfunction and non-monosymptomatic when bedwetting is associated with daily bladder and voiding problems. There are several causes of nocturnal enuresis including increased urine output at night, small functional bladder capacity at night, a lack of arousability at night, or a combination of these.
In the daytime, incontinence may be from a variety of causes including detrusor overactivity, dysfunctional voiding and structural abnormalities including ectopic ureters in females, neurogenic bladder and other congenital anomalies. Daytime incontinence in children is also associated with constipation. In children with overactive bladder symptoms and detrusor overactivity the symptoms include frequency, urgency and urgency incontinence. With dysfunctional voiding, children may present with urgency from holding their urine for prolonged periods of time. Urinary frequency can develop from increased post-void residual urine related to incomplete emptying and voiding against a tight pelvic outlet as well as from reactive detrusor overactivity. Children with dysfunctional voiding often present with a history of constipation and urinary tract infections.
Assessment
An accurate history and physical examination are necessary to rule out congenital/structural abnormalities. A bladder scan post-void residual is helpful in children with symptoms of dysfunctional voiding. When taking the patient’s history, bowel habits should be reviewed to obtain information about any emptying disorder. The main diagnostic tool is the bladder diary including registration of nocturnal urine volume (pad weight + first morning urine void volume). In addition, the frequency of daytime voids, accidents and sensation of urgency associated with each accident should be noted. Fluid intake, type and volume should also be recorded for at least 3 days on a validated chart.
In children with a history suspicious for dysfunctional voiding, a uroflow/EMG is helpful, as it will demonstrate incomplete sphincter relaxation or increased pelvic floor muscle activity during voiding and is associated with an interrupted or staccato urinary flow curve.
A KUB is useful in children to assess for constipation if the history is suggestive.
A renal/bladder ultrasound should be obtained in those children with a suspicion of a congenital urologic anomaly (i.e. ectopic ureter), males with daytime urinary incontinence and males with high post-void residuals to rule out structural abnormalities
A urodynamic study is not routinely performed. Rather, it is reserved for patients who fail treatment.
Treatment
Nocturnal enuresis - fluid restriction (no fluids 2 hours before going to bed) as well as voiding just before going to bed are essential. Additional therapies include the bedwetting alarm and desmopressin acetate.
Daytime incontinence – dietary and lifestyle modification is useful in children with daytime incontinence. Children/parents should be instructed regarding normal fluid intake, avoidance of caffeinated, carbonated and highly acidic fluids/food as well as a proper voiding interval. Proper toileting position (all the way back on toilet seat, upright with legs apart, 90 degrees between thighs and legs) is also important. In those children with increased post-void residuals, double-voiding should be instituted (after initial void is finished, a second voiding attempt is made ). Children should be instructed to relax the pelvic floor to void and not to push to urinate. Biofeedback is useful in children who do not respond to behavioural therapy. For older children with daytime incontinence, the next step after behavioural modification or biofeedback is anticholinergic medication. If incomplete emptying persists after standard interventions fail, particularly if accompanied by recurrent UTI, clean intermittent catheterisation should be considered. Concomitant management of associated constipation/obstipation in children with bladder dysfunction is critical to optimising success.
Conclusion
Children’s incontinence (diurnal and nocturnal enuresis) has a significant impact on quality of life and may be associated with long-term morbidity. Early recognition with intervention and management are therefore critical. Several studies in the adult literature suggest that children with voiding dysfunction are at increased risk for incontinence as adults. Hopefully, early identification and management can reduce potential long-term risks. For those children with chronic bladder dysfunction, it is paramount to ensure continuity of care from childhood into adolescence and adulthood.
References
- Nevéus T, von Gontard A, Hoebeke P, et al. The standardization of terminology of lower urinary tract function in children and adolescents: report from the Standardisation Committee of the International Children’s Continence Society. J Urol 2006;176:314-24.
- Neveus T, Eggart P, Evans J, et al. Evaluation of and treatment for monosymptomatic enuresis. A standardisation document forms the International Children’s Continence Society. J Urol 2010;183: 441-447.
- Franco I. Functional bladder problems in children: pathophysiology, diagnosis, and treatment. Pediatr Clin North Am 2012; 59(4):783-817.
- Kilic N, Balkan E, Akgoz S, et al. Comparison of the effectiveness and side-effects of tolterodine and oxybutynin in children with detrusor instability. Int J Urol 2006; 13(2):105-8.