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Nocturnal Enuresis Management – How to Achieve Dry Nights
Therefore, enuretic children do not wake up before micturition even the late afternoon, soft/carbonated drinks and salty food should be
with auditory stimuli (9.3% were woken in a PNE group versus 39.7% avoided. In the evening, a low-calcium diet should be avoided, and at
in a control group).
19,20
A decrease in the prepulse reflex (prepulse 6pm the quantity of liquid taken should be drastically decreased.
inhibition [PPI]) suggests a central dysfunctioning of the pontic mantel
area beside the micturition and detrusor inhibition centres.
15–21
Sleep We recommend that a regular daytime voiding pattern be established,
apnoea and hypertrophic adenoids associated with hypercapnia can with complete voiding five to six times a day (especially first thing in
increase polyuria. These children can be improved after performing the morning and at bedtime). Sufferers should be encouraged to void
surgery on the adenoids.
22
when they feel that their bladder is full, to void when as relaxed as
possible until the bladder is completely empty and to treat constipation
The Voiding Chart and/or encopresis.
In 2006, the ICCS recommended the use of a frequency/volume chart
over a 24-hour period to precisely measure urinary frequency and Voiding Chart
daytime urine production, average voided volume and the highest The voiding and fluid intake recommendations should be respected for at
voided volume. The data of the voiding chart provide information on least two weeks and the number of wet or dry nights should be reported
the pathophysiological mechanisms of PNE.
1
on a chart. The simple diet and voiding guidelines associated with the
voiding chart are used to treat about 20% of enuretic children.
1,28–30
Urine production is regulated by the circadian rhythm of the ADH
arginine vasopressin (AVP) and by the excretion of solutes. Nocturnal Third Step – Therapy
urine production decreases (by a ratio of two-thirds to one-third),
whereas its concentration increases (≥800mOsm/l).
3
It is widely Pharmacological Therapy
accepted that enuretics have high nocturnal urine volume production
23
dDAVP is not recommended before six years of age. Prior to starting
and that nocturnal urine volume is greater on wet nights than on dry the treatment, the patient must be motivated and have undergone
nights.
24
Polyuria is characterised by large amounts of urine being counselling. dDAVP is the first line of treatment for nocturnal polyuria
passed: at least 2.5l over 24 hours in adults. However, it is not clear PNE after diet and voiding dysfunctions have been corrected.
how osmolality becomes low (<800mOsm/l). There is a reversal of the
circadian rhythm of the AVP secretion, but this is probably Until 2006, dDAVP was administered intranasally at bedtime (20–40µg)
multifactorial in origin. Restricting the intake of beverages and or orally (0.2–0.4mg tablets). In France, the sale of the intranasal spray
desmopressin (dDAVP), an analogue of vasopressin, are effective in was stopped in April 2006 because it was not convenient or reliable. It
this type of enuresis. was replaced by 0.2mg tablets and 60–240µg lyophilisat. Lyophilisat
has the advantage of being highly hydrophilic and immediately
Nocturnal polyuria can be explained by two main factors: dissolves in the mouth. This method fits particularly well with children
under 12 years of age
30
and complies with the paediatrics
• AVP production impairment, most likely through aquaporin 2 recommendations of the European Medicines Agency (EMEA).
(AQP2), explains the positive response to dDAVP; Therefore, the bioavailability of lyophilisat is about 60% higher than
• solute excretion dysfunction, especially sodium with renin/ that of tablets. Therefore, 60, 120 and 240µg of lyophilisat are
angiotensin/aldosteron complex. Several studies have found hyper- bioequivalent to 0.1, 0.2 and 0.4mg of tablets. The usual dose is
natriuria, hyperkaliuria or hypochloraemia, which could be 120–240µg. The antidiuretic activity starts after one hour and lasts for
explained by the wide variety in the diets of different human seven to 11 hours, covering the sleep duration in children.
31
populations depending on the geographical location.
After six months, 60–70% of patients will respond to dDVAP
Small Functional Bladder Capacity treatment with fewer than 50% wet nights.
32
Practitioners should
According to the ICCS, the Koff formula (30ml + age in years x 30) is inform the patients and their parents of any adverse effects. There is a
used to calculate the theoretical expected bladder capacity in risk of water intoxication by hyponatraemia if the patient drinks a lot
millilitres. We can conclude that the nocturnal bladder capacity is small of water while taking dDAVP.
1
The rate of minor adverse effects such
if the output during the night is 70% less than the expected daytime as abdominal pain and headache is less than 1%.
33
capacity. Furthermore, 30% of enuretics have night-time bladder
overactivity. In these cases we can predict that the result of the dDAVP The initial posology is 0.20mg of tablets per day or 60µg of lyophilisat
treatment will be poor.
25–27
per day. According to the response of patients, the dose can be
increased by 0.1mg of tablets per day or 60µg of lyophilisat per day
Second Step – Basic Information and Counselling and up to 0.4mg of tablets per day or 240µg of lyophilisat per day. In
rare cases it may be necessary to increase the posology to 0.6mg of
Voiding and Drinking Habits tablets per day or 360µg of lyophilisat per day.
Enuretic children should have the normal recommended intake of
45–60ml/kg per day, but it should be consumed between 7am dDAVP can partially or completely cure enuretic children and should
and 6pm. be continued on a long-term basis with breaks every three months.
The dose should be reduced gradually during the first month. The
Furthermore, carbonated beverages should be avoided. At breakfast, minimum dose of dDAVP required to control wet nights should
liquid intake should represent one-third of the daily amount. During be defined.
EUROPEAN UROLOGICAL REVIEW 123