Frequently Asked Questions
Below please find relevant questions and answers on the subject of enuresis divided into these two categories
The Condition
General
The Condition
Q: Do bedwetting children sleep deeper?
A: Parents of enuretic children are almost unanimous in stating that their children are nearly impossible to wake up. Attempts to validate this opinion have however been largely unsuccessful and sleep patterns appear to be perfectly normal in children with PNE. Despite a normal sleep pattern, however evidence has emerged that children with nocturnal enuresis may have an abnormal arousal response to a full bladder. (1)
Q: Is there any evidence that nocturnal enuresis results from nocturnal polyuria?
A: Yes – in many studies it has been shown that a considerable number of patients with nocturnal enuresis suffer from a relatively high nocturnal urine output. This does not in itself explain enuresis, but merely that the bladder capacity is exceeded so that voiding occurs during sleep. (2)
Q: Is a small bladder capacity a cause of enuresis?
A: There is certainly some evidence that the bladder muscles are not properly relaxed during sleep in some individuals with primary nocturnal enuresis (3). This leads to a decreased bladder capacity and earlier initiation of the micturition reflex. The balance between bladder capacity and nocturnal urine production is important in determining the onset of an enuretic event (4). If nocturnal urine production in children is higher than the bladder capacity enuresis will occur.
A study by Vande Walle (5) provides evidence of the balance between urine volume and the bladder volume. He further relates the imbalance to the age of the child and suggests it is an immaturity of the mechanism for this balance which leads to enuresis. The mechanism usually matures during the ages of 2 to 5. However in some subjects this maturation is delayed and results in nocturnal polyuria and enuresis.
General
Q: What is the recommended fluid intake over a day?
A: There is no recommended fluid intake over 24 hours as each person has his or her own “normal” intake. Sensible drinking is recommended during the day. There are some 'usual' amounts illustrated on the Clinical Management Tool as follows:
Maintenance fluid intake in paediatrics can be calculated according to the table below. (6)
| 0-10kg | 100 ml/kg |
| 11-20kg | 1,000 ml + 50 ml/kg for each 1 kg above 10 kg |
| above 20kg | 1,500 ml + 20 ml/kg for each 1 kg above 20 kg (to a maximum of 2,400 ml) |
* For an average 5 year old weighing 18-20 kg, fluid intake should be 1,400 - 1,500 ml
* For an average 10 year old weighing 33-35 kg, fluid intake should be 1,760 - 1,800 ml
* For an average 15 year old weighing 56-60 kg, fluid intake should be 2,220 - 2,300 ml
There is, of course, considerable variability from day to day and between individuals. This volume should be considered the target intake for children with bedwetting, aiming to take most of the fluid during the morning and early afternoon.
References
1. Butler R. Scand J Urol Nephrol 2000; 34:270-277
2. Rittig S et al. Am J Physiol 1989;25(4):F664-667
3. Norgaard JP et al. Urology 1985; XXVI:316-319
4. Norgaard JP et al. Scan J Urol Nephrol 1999;Suppl 202:53-55
5. Vande Walle J et al. Br J Urol 1998; 81(3):40-45
6. Evans J et al. Nocturnal Enuresis Clinical Management Tool - 2006.
