This site is intended for health professionals only

What is nocturnal enuresis: bedwetting for beginners

Rachel J McKenzie
BMedSci(Hons) BM BS MRCGP
GP Principal
Dunvegan
Isle of Skye

Primary nocturnal enuresis (NE) affects over 500,000 children in the UK between the ages of 5 and 16 years. It is more common in boys. Primary NE is known to be hereditary, affecting 77% of children if both parents had NE. Possible mechanisms include reduced nocturnal antidiuretic hormone (ADH) and smaller bladder capacity. Children who develop secondary enuresis may do so for a number of reasons including urinary tract infection (UTI), diabetes and constipation, or after a period of stress such as the birth of a sibling.

Treatment of NE(1,2)
Parents may have unreasonable expectations and should be advised to be patient and offer plenty of love and reassurance. Some children develop night-time bladder control later than others. Treatment depends on the understanding and motivation of the child. Traditionally treatment was discouraged in children younger than seven. Specialist enuresis clinics are located in many regions throughout the UK.

Enuresis alarms
These involve a sensor, which is activated when it gets wet. This wakens the child, who should get up and finish in the toilet. The alarm has to be used every night, often for several months. Enuresis alarms are effective in up to 80% of children, but the dropout rate can be as high as 25%. Adverse socioeconomic factors are known to negatively affect the success rate.(3) Children may relapse and need a further course.
 
Success is more likely in motivated children, which is helped by giving children responsibility and offering lots of praise for any sign of progress.

Daytime bladder training
Some children seem to need to go to the toilet more frequently than others. These children can benefit from a bladder-training programme, where during the day the length of time between trips to the toilet is gradually increased. Evidence shows that daytime bladder training rarely cures NE without the use of other treatments, and works best when combined with enuresis alarms.

Star charts
This involves rewarding the child for progress, initially for even small signs of improvement. This acts as a visual reminder and is particularly useful for children who don't seem to mind having wet nights. It is important to be consistent and not to punish when things don't go well. Some parents count up stars and cash them in for a special treat. There is little evidence regarding the success or otherwise of star charts as a treatment for NE.

Drugs
Desmopressin nasal spray A synthetic analogue of ADH that reduces nocturnal urine output. It acts rapidly so can be used as a short-term measure or in conjunction with enuresis alarms. It is contraindicated in patients with cystic fibrosis, uraemia or raised blood pressure. Nasal irritation is the most common side-effect. Desmopressin increases dry nights, but enuresis may resume when treatment is stopped. It is useful, however, as a measure to show children that dryness is possible, or as a short-term treatment to allow children to sleep away from home without embarrassment.

Imipramine A tricyclic antidepressant widely used to treat NE. Its mechanism of action is not fully understood, but it has both anticholinergic and antidiuretic effects. Side-effects include drowsiness and lethargy, and deaths from overdose have occurred. There is no evidence that imipramine works in the long term.

Oxybutynin An anticholinergic drug widely used to treat incontinence due to detrusor instability. It has been suggested as a treatment for NE where bladder irritability is a factor. One study reported no significant benefits.

Other measures Parents are advised to make it easy for children to get to the toilet at night. Children should be encouraged to tell their parents when their bed is wet and help change their sheets, as many respond to being given such responsibility. Parents should be advised against "lifting" sleeping children and taking them to the toilet, as this actively encourages a child to pass urine while asleep. Bladder training is also usually compromised if nappies are worn regularly as this gives the child little encouragement or incentive to get dry.

References

  1. Evans JHC. Evidence based management of nocturnal enuresis. BMJ 2001;323:1167-9.
  2. Bosson S, Lyth N. Nocturnal ­enuresis. Clin Evidence2001;5:268-73.
  3. Rolands D. Social deprivation affects outcome of nocturnal enuresis. BMJ 2001;324:677.

Resources
ERIC - Enuresis Resource and Information Centre
34 Old School House
Britannia Road
Kingswood
Bristol BS15 8DB
T:0117 960 3060
F:0117 960 0401
W:www.enuresis.org.uk