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Urinary incontinence in children: the facts

Charlotte Mawby
RGN RSCN
Children's Continence Specialist Nurse

Urinary incontinence (UI) is the lack or loss of urinary control in a child beyond toilet-training age.(1) This affects a number of children, causing distress and embarrassment to the child and their family. It impacts on the child's home and school life, limits friendship groups and attendance at clubs, and can ultimately reduce a child's self-esteem. UI is treatable; however, if left untreated it can lead to social isolation and bullying.

Cause of urinary incontinence
The treatment and assessment of UI is made difficult due to the many and varied causes listed in Box 1. The child may present with single or multiple causes.

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Overactive bladder
This is when the bladder contracts strongly and without warning, often causing urgency. The muscles surrounding the urethra may not be able to keep urine from being passed.

Small bladder capacity
This can be as a result of poor drinking habits. Drinks need to be taken regularly throughout the day to ensure the bladder is filled and emptied approximately 6-8 times a day, increasing bladder capacity.

Irritable bladder
Irritable bladder results from not drinking a sufficient volume of water-based drinks, leading to concentrated urine, which may cause unwanted detrusor contraction. Drinks containing caffeine, such as tea, coffee, hot chocolate and certain fizzy drinks, or those with artificial colourings can result in "irritant" urine and may lead to unwanted detrusor contraction and leakage.

Infrequent voiding
This is the voluntary holding of urine for a prolonged period of time. A child might dislike using school toilets or may refuse to interrupt an enjoyable activity to go and pass urine. Ignoring the signals of a full bladder causes it to overfill, and leaking of urine occurs.

Toilet training
Training methods and habits can contribute to UI.(2) Toilet training instigated by an adult and not independently by the child can inhibit the understanding of the messages from the bladder to the brain, limiting the sensation for the need to urinate.

Nocturnal enuresis
Nocturnal enuresis is the involuntary passing of urine during sleep in the absence of any identified physical abnormality in a child over five years. Main components are lack of vasopressin, bladder instability and lack of arousal from sleep.(3)

Urinary infections
Urinary tract infections (UTIs) can cause secondary enuresis (see Box 2). A child presenting with secondary enuresis should have a urine sample tested. Children who have repeated UTIs may develop a dysfunctional bladder.(1)

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Normal micturition
Voiding is a complex activity. The bladder stores urine in a balloon-like muscular sac known as the detrusor muscle. The control of this involves intact nerves, muscles, spinal cord and brain.(4) As the detrusor muscle contracts, the pelvic floor muscles and urethral sphincter muscles relax and urine is passed through the urethra.
A baby's bladder contracts and empties automatically when full.(5) After the age of 18 months, as the nervous system matures, a child starts to understand the signal between the bladder and the brain, and gains the control to empty the bladder in an appropriate place, such as the potty. Children with developmental delay often gain these skills in line with their development age rather than chronological age.(1)
 
Assessment
A baseline assessment should include all of the points in Box 3. Normal bladder capacity can be fairly well assessed by:(8)
Bladder capacity in ml = 30 + (age in years × 30)
For example, a 5 years old is 30 + (5 × 30) = 180ml.
This can also be calculated by (age + 1) × 30 = bladder capacity. For example, (5 +1) × 30 = 180ml.

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Advice and education
Many parents think that restricting fluid intake will help prevent incontinence. In fact this will make UI worse. Bladder capacity remains small; urine remains concentrated, causing irritation to the bladder; and thus more wetting. It is important that the practitioner fully explains this to the parents and child.
Advice regarding the amount and types of suitable drinks is essential. Nurses should advise that 6-8 cups of water, weak squash and diluted juice are taken at evenly spaced intervals throughout the day.
Regular use of the toilet, 6-8 times a day, approximately every 1½-2 hours, fitting them into school break times where possible, should be encouraged.
Inform parents and children what the normal bladder capacity should be; this helps them to understand the expected target. Constipation must be treated before or in conjunction with the bladder retraining - if left untreated this may directly cause UI.
UI will improve dramatically for most children, when parents and children have the knowledge to make the relevant lifestyle changes needed to improve the situation. Over time, bladder capacity increases, overactivity settles, the child learns to empty the bladder appropriately, and anxiety about UI reduces. Regular support from the practitioner is essential to help sustain motivation, troubleshoot problems and monitor progress. Asking the child and family to record the child's fluid intake and urine output for a full day every few weeks can help monitor progress.
A child over five years old with a history of daytime wetting who has not responded to a toilet/drinking programme should be referred for further investigations.

Products available
Washable and disposable products are available for families to purchase. Reusable products are cost-effective, but disposable products more convenient. Products available include absorbent padded pants, briefs and boxer shorts. Protective mattress, pillows, duvets covers and sleeping bag liners could also be considered.(9)

Treatments available

Bladder overactivity
Antimuscarinic/anticholinergic drugs such as oxybutynin can be helpful in reducing uninhibited detrusor contractions, thus enlarging the child's functional bladder capacity.

Nocturnal enuresis
The mainstay of treatment is the enuresis alarm.(10) A water sensitive paddle is placed in the pyjamas or pants, connected by a wire to a battery operated box pinned to the child's night clothes. When the child starts to urinate the alarm sounds waking the child, who should then go to the toilet and finish emptying the bladder, reset the alarm and return to bed. Parental support and family tolerance is essential to achieve success.
Anti-diuretic hormone (ADH) can be increased by a synthetic version known as desmopressin. Increasing ADH levels reduces nocturnal urine production. This is particularly effective for use at school camps or sleeping over, and should be considered in the medium term for those unresponsive to treatment or intolerant to use of an enuresis alarm. Advice needs to be given to the child and family regarding restricted oral fluid intake following a dose of desmopressin; consult an up-to-date copy of the BNF for further details.
All children with urinary incontinence should receive assessment and advice and support from an appropriately trained healthcare professional, such as GP, health visitor or children's continence nurse specialist, taking into account all the likely causes already mentioned.

Implications for physical and mental health
Excoriation to skin from incontinence dermatitis may be experienced and will require additional care to personal hygiene.
UI can be distressing to a child, causing embarrassment and exclusion, and provoking ridicule and bullying at home,school or clubs.
School attendance should not be affected as all schools have an inclusion policy and guidelines for managing children with a medical condition such as UI (sometimes referred to as "Personal Care Policy").
UI can be indicative of other problems, such as emotional issues, rather than a physical disorder. The practitioner needs to adopt a skilled approach to history taking in order to obtain all information offered during consultation, and be prepared to tackle them and/or refer onto other relevant agencies.
Embarrassment relating to continence often stops help being sought when the problem is first apparent. For the family, UI can cause social embarrassment and exclusion, and increased financial expense due to washing and damage to bedding, clothing, and furniture.

Conclusion
Urinary incontinence in children has been proven to have a detrimental effect on the quality of life of the child and their family. The success of any treatment offered is wholly dependent on a thorough and accurate assessment undertaken by a skilled healthcare professional.
Unfortunately, there is very little current research evidence to support or clarify the ideal age at which to start toilet training a child. Most articles agree that physiological maturity, communication skills, mobility and social skills are required for toilet training to begin. Clearer guidance based on good-quality research would be welcomed to enable healthcare professionals to offer sound advice to parents regarding toilet training their children, with a view to preventing potential problems while attaining success.

References

  1. Getliffe K, Dolman M, editors. Promoting continence: a clinical research source. 2nd ed. London: Bailliere Tindall; 2003.
  2. Bakker E, et al. BJU Int 2002;90:456.
  3. Butler R. Nocturnal enuresis resource pack. ERIC (4th ed). Available from: http://www.eric.org.uk
  4. Rogers J. Nurs Standard 2002;16(32):45-52.
  5. Yeung C, et al. Br J Urol 1995;76(2):235-40.
  6. Rogers J. Paediatric bladder care pathways. Available from http://www.promocon.co.uk
  7. Rogers J. Paediatric bowel care pathways. Available from http://www.norgine.co.uk
  8. Hjalmas K. Scand J Urol Nephrol Suppl 1988;114:20-7.
  9. ERIC. Education and resources for improving childhood continence. Available from http://www.eric.org.uk
  10. Harari M, Moulden A. J Paediatr Child Health 2000;36:78.

Resources
British National Formulary
W:www.bnf.org/bnf