Nocturnal Enuresis (Bed-wetting)

Perhaps one of the more frequent discussions in the pediatric practice is related to the parental concern over the habitual bed-wetting of a child. About 20% of children at age 5 years wet the bed at least once monthly and of these 5% of the boys and 1% of the girls wet nightly. About 15% of all bedwetters stop wetting each year after 5 years old.(i.)The majority of children with primary enuresis have no known cause for this condition. They are unable to recognize the sensation of a full bladder during sleep.(ii.) A small bladder capacity might be a factor especially in those children who have frequent urination during the day and may in fact wet several times at night. Only 2-3% of children with primary enuresis have a pathologic cause. Some signs of an organic cause can include painful urination, daytime wetness, frequent drinking and excessive thirst, constipation and soiling.(iii.) Genetic factors may be involved in this condition, as there is a 45% probability of having a child with enuresis if one of the parents was a bedwetter and a 77% probability if both parents were enuretic. Studies support that primary enuresis is more of a biological issue rather than a psychological or social issue.(iv.)

Generally speaking, a child with primary enuresis who has a normal urinalysis and no symptoms of organic problems needs no further involved work-up. Subjecting a child to a barrage of tests serves no purpose other than to make him more uncomfortable with this condition and also to make him view it as a problem as opposed to a normal developmental variant. Measuring the volume made when a full bladder is emptied can provide some idea of bladder capacity. Normal volume for a child is (age+ 2) ounces with adult levels being at 12-16 ounces.(v.) A documented small bladder may be reassuring to the parent and child as it provides a more physical reason for the enuresis.

Obviously treatment is geared to eleviating the wetting at night. The goal, which must be achieved, is for the child to awake to empty his bladder as needed at night. It is imperative that where applicable, any physical predisposing factors be treated. Various treatment modalities are available to dealing with primary enuresis. These include pharmacological, mechanical, and behavioral modification-like techniques. Imperatives to all treatments are various overriding measures. Toilet access should be easy for the child, helping the child feel in control of solving this condition, avoiding drinking before bedtime (no drinking within two hours prior to bed), empty bladder prior to bed, have the child help in changing his bed and dealing with the wet bed linens.The child should be encouraged and even rewarded for dry nights but should not receive negative treatment for wet nights. It is counterproductive to keep the child in diapers or pull-ups at night.(vi.) They may make the child less aware of his wetting and may likewise convey the message that we expect him to be wet. They are however useful for camping trips or overnights at hotels etc. Keeping a calendar or ledger with a record of dry mornings and wake ups at night to use the bathroom should be included as this record can be brought into the office to review progress with the provider who instituted treatment.

Treatment of enuresis can create some controversy as there are proponents of medical treatment and those who feel behavioral treatment is more useful. There are also those who advocate no treatment as this condition will correct itself with age. The treatment modalities are as follows:

Enuresis alarms: Varying in proce between $40-$60 these alarms are devices which are triggered by the child’s wetting. Most frequently a small pad is worm inside the underpants at night. This pad is attached by a wire to a small unit which clips onto the child’s pajamas. When the pad is moistened from wetting a circuit is completed and sets off the alarm. Most frequently this results in an audio alarm which should wake the child (and frequently the household). Another alarm causes a tactile vibration, which is intended to wake the child without disturbing the entire household. Alarms in general have a good track record with varying cure rates from 68% to 84%. Relapses may occur at a rate of 10-15% after the alarm is discontinued. They do require a commitment from all involved. Failures of these devices are frequently attributed to the child not being awakened and for parents giving up too soon. It requires 2-3 months to get full benefits from these alarms.

Desmopressin (DDAVP©)- This has become one of the more popular medical therapies. In most cases this therapy involves using a nasal spray prior to bed. The drug works by reducing urine production and increasing water retention. The drug continues to act for 10-12 hours. Reports have dfiffering statistics regarding efficacy as well as relapse rate. One review by Moffatt showed 24.5% were dry on medication but there was a 94.3% relapse rate when the medication was discontinued.(vii.) Another report comparing desmopressin and alarms showed improvement in 70% with desmopressin and 86% with the alarm. There was a significantly higher relapse rate in those treated with the desmopressin verses those treated with the alarm.(viii.) DDAVP may have a useful role in periodic control of enuresis although some still use it for primary treatment of enuresis.

Imipramine- This is a drug which effects the bladder by decreasing the muscular excitability. It lasts 8-12 hours and has an initial cure rate of 10-60%. Unfortunately it can have a relapse rate of >90%. This drug if taken in higher than recommended doses can have toxic effects and in England is the largest cause of fatal poisoning in children under 5 years old. (ix.)

Oxybutynin (Ditropan©) Another drug which decreases the spasmodic contractions of the bladder muscles. Again there are varying reports of success. This may be a drug more used in children who display urgency and symptoms of bladder dysfunction.

Enuresis is a fairly common condition, which should be addressed with your child’s physician. Of primary importance is that a thorough history is elicited and if indicated appropriate tests are done. An over zealous investigation is inappropriate in simple primary nocturnal enuresis. Those with secondary symptoms such as daytime frequency, poor urinary stream, uncomfortable urination or constipation may require a more involved evaluation. The decision to attempt to treat simple primary enuresis should be made by the parent, the physician and the child. Remember a child who really doesn’t have an interest in remaining dry at night will be very difficult to help. On the other hand one does not wish to make the child over concerned regarding his bedwetting . Likewise the decision of which method of treatment is best for your child should be determined after conferencing with your child’s physician. All parties should feel comfortable with the treatment. Letting the physician review progress with your child at periodic intervals has been useful. Above all one must be patient and not turn this rather benign condition into a source of anxiety or fear.

Reference List

i.Schmitt MD,Barton D, Nocturnal Enuresis; Pediatrics in Review, Vol.18,No.6. June 1997

ii.Ibid.

iii.Ibid.

iv.Fergusson,DM et al, "Factors Related to the age of attainment of nocturnal bladder control: an 8-year longitudinal study"; Pediatrics Vol.7,Issue 5, Nov.1986

v.Schmitt MD,Barton D, Nocturnal Enuresis; Pediatrics in Review, Vol.18,No.6. June 1997

vi.Schmitt MD,Barton D, Nocturnal Enuresis; Pediatrics in Review, Vol.18,No.6. June 1997

vii.Schmitt MD,Barton D, Nocturnal Enuresis; Pediatrics in Review, Vol.18,No.6. June 1997

viii.Wille,S., "Comparison of desmopressin and enuresis alarm for nocturnal enuresis", Archives of Disease in Childhood, Vol 61,30-33, 1986

ix.Schmitt MD,Barton D, Nocturnal Enuresis; Pediatrics in Review, Vol.18,No.6. June 1997

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