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enuresis
DEFINITION:
The involuntary voiding of urine after the age of 6 years.
EPIDEMIOLOGY:
 incidence: 25-33% of 4 year old children, 15% of 5-6 year olds, 5-7% of 7 year olds, 1% of 15 year olds
 age of onset:
 by definition after the age of 6
 risk factors:
 family history
 75% if both parents affected
 40% if one parent affected
 sex
 M > F (nocturnal)
 F > M (diurnal)
DIFFERENTIAL DIAGNOSIS:
1. Organic
 bladder instability
 constipation
 Diabetes Mellitus or Insipidus
 renal (medullary) damage
 urinary tract infection
 neurologic dysfunction
2. Non-Organic
 deep sleeper
 emotional disturbance
 excessive water drinking
 learned ("holding-on") behaviour
 mental retardation
 sexual abuse
DEFINITIONS:
 Nocturnal: nighttime bedwetting
 Diurnal: daytime wetting +/- nighttime bedwetting
 Primary: has never been dry for longer than 6 months
 Secondary: wetting after a minimal 6 month period of dryness (less common than primary enuresis)
 Relapse: more than 2 wet nights in 2 weeks
 Initial Success: 14 consecutive dry nights within a 16 wk treatment
 Continued Sucess: no relapse in the 6 months after initial success
 Complete Success: no relapse in the 2 years after initial success
PATHOGENESIS:
1. Development of Bladder Control
 babies - void 12-16 times per day
 1-2 years - develop an awareness of a full bladder
 2-4 years - recognize the sensation of voiding
 develop the ability to "hold-on"
 4-5 years - can initiate voiding voluntarily (even before the bladder is full)
 6-7 years - can hold as necessary and void at any degree of filling
2. Nocturnal Enuresis
 a developmental issue
 delay in the development of the nocturnal release of ADH
3. Diurnal Enuresis
 a behavioural issue
 "holding-on" -> overflow incontinence
CLINICAL FEATURES:
1. History
 primary or secondary
 nocturnal or diurnal
 frequency
 # of times per week
 # of times per night
 risk factors
 family history
 recurrent UTI (frequency, dysuria)
 constipation or encopresis
 neurologic defects
 diabetes mellitus (polyuria, polydypsia)
 "holding-on" behaviour
 squatting
 squirming
 dancing
 starer
 "holding-on" features
 do not void when first arise in the morning
 void only 2-3 times per day (normal 5-7 times/day)
 short bathroom duration
 motivation of child and family
2. Physical Examination
 growth parameters
 blood pressure
 genital examination
 neurologic examination
 reflexes
 abnormalities of extremities or spine
 rectal examination (constipation)
INVESTIGATIONS:
1. First Line
1. Primary Enuresis
 complete urinalysis
 R & M, C & S, osmolality (day & night)
2. Secondary Enuresis
 complete urinalysis
 renal ultrasound
2. Second Line
1. Imaging Studies
 renal ultrasound
 VCUG - measures bladder capacity
 cystoscopy
2. Osmolality
 9 urine samples over 3 consecutive days at 1600, 2200 and 1st am samples while the child is fluid restricted to 25cc/ kg/day
3. Bladder Capacity
 normal capacity in average child is age + 2 = ounces (i.e., 6 year old will have a bladder capacity of 8 ozs.)
MANAGEMENT:
1. Patient and Family Counselling
 to provide reassurance and emotional support
 describe scope of enuresis in society
 explain correctable organic causes of enuresis
 explain that enuresis is a self-resolving condition and not a disease
 explain that child has no control over condition
2. Correct any underlying causes
 UTI (antibiotics prophylaxis for recurrent UTI - Septra qhs)
 constipation
3. Manage daytime wetting before nighttime wetting
4. Principles of therapy (3)
1. Increase Bladder Capacity
 for daytime wetting
 double fluid intake in order to make "holding-on" more difficult
 oxybutynin or an anticholinergic agent to control bladder instability
2. Establish Circadian Rhythm of Serum ADH
 DDAVP (desmopressin)
 an analogue of antidiuretic hormone (ADH)
 acts by duplicating the normal nighttime increase in
 ADH
 initially use 10 ug intranasally qhs x 3 nights and if no effect increase to 20 ug intranasally qhs x 3 nights and if no effect increase to 30 ug intranasally qhs x 3 nights and if no effect increase to 40 ug intranasally qhs x 3 nights
 high rate of recurrence once terminated (not curative)
 works best in those older than 8 years
 response within 1 week
3. Patient Conditioning
 Alarm Systems
 Palco
 works best in older children ( > 6 years)
 10% spontaneous remission but 30% non-responders
 child and family must be motivated for this to work
 expect response over 3-4 weeks with low relapse rate
 if 2 wks dry -> challenge
 if 2 wks dry on challenge -> cured
 Reward System
 child takes responsibility for problem - changes sheets, star system
5. Others
1. Imipramine
 an antidepressant thought to decrease the level of sleep in those children who are deep sleepers
 initial dose of 25 mg po qhs; may be increased to 50 then 75 mg po qhs
 dose dependent and once dryness achieved a gradual withdrawal over a few months is necessary
 effectiveness is not related to serum levels
2. Voiding Routine
 void q1.5-2h
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TABLE 1
Possible Etiologies of Primary Nocturnal Enuresis
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Factor
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Pathophysiology
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Evidence
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Developmental delay
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Delayed functional maturation of the central nervous system causing failure of arousal
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Spontaneous cure rate as children grow older, animal studies
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Genetics
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Unclear
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Family history, gene identification, linkage analysis
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Sleep disorder
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Deep sleep
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Sleep studies
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Behavior and psychologic disorders
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Unclear
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Result rather than cause
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Anatomy
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None found
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Children with primary nocturnal enuresis have normal physical examinations
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Antidiuretic hormone levels
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Low level of nighttime antidiuretic hormone secretion in children with primary nocturnal enuresis causes urine overproduction
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Hormone studies5,6
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Urodynamic and radiologic evaluation are not necessary in children with straightforward primary nocturnal enuresis.
Treatment
The first step toward proper treatment is to have the child's parents complete a questionnaire that reviews the child's history of enuresis. The physician should also consider the following points: children younger than six years of age are generally not evaluated if they have enuresis and no other ongoing urologic problems; treatment modalities will not be successful if the parents and the child do not have a cooperative attitude, and treatment will be unsuccessful if the family's social structure and home environment do not provide consistent support and care for the child.
Consistent follow-up is essential in gauging the results of therapeutic intervention. Objective documentation using a diary can help the physician, the patient and the family monitor progress. Improvement is usually defined as a 50 percent reduction in the number of nights that bed-wetting occurs. Cure or resolution of primary nocturnal enuresis is defined as only one or two wet nights over a three-month period, and documentation that the child has wakened spontaneously and gone to the bathroom to void.
Treatment of nocturnal enuresis can be divided into two broad categories: nonpharmacologic and pharmacologic. Nonpharmacologic treatment of enuresis includes motivational therapy, behavior modification (conditioning therapy), bladder-training exercises, psychotherapy, diet therapy and hypnotherapy. Because of increased awareness that primary nocturnal enuresis can be a significant psychosocial stressor, pharmacologic treatment of primary nocturnal enuresis has evolved significantly over the past 15 years, and safer, more effective medications are now available.
Nonpharmacologic Methods
Motivational Therapy. Motivational therapy for the treatment of nocturnal enuresis involves reassuring the parents and the child, removing the guilt associated with bed-wetting and providing emotional support to the child. The child should be instructed about taking responsibility for his or her bed-wetting. In other words, children with nocturnal enuresis should be helped to understand the condition and to realize that while they did not cause the problem, they do have a role in the treatment plan.
Positive reinforcement for desired behavior should be instituted. One way to carry out a program of motivational therapy is to set up a diary and chart, with a reward system for each night the child stays dry.
The cure, or resolution rate for children receiving motivational therapy has been estimated to be only 25 percent (a figure close to the 15 percent rate of spontaneous resolution), yet up to 70 percent of children with primary noctural enuresis show marked improvement.23 Long-term follow-up is necessary, however, and a relapse rate of approximately 5 percent has been reported.24
Motivational therapy appears to be a reasonable first-line approach to treating children with primary nocturnal enuresis, especially younger children. However, if therapy is not successful within three to six months, a different treatment option (e.g., behavior modification or pharmacologic therapy) should be offered.
Hypnotherapy, diet therapy and psychotherapy are treatment modalities that have not been widely used in children with primary nocturnal enuresis. Hypnotherapy has had good success rates in limited trials, but there has been no long-term follow-up. Diet therapy also may be an option for some patients. Children with a higher caffeine intake may be more prone to enuretic episodes. Foods suspected to be contributing agents for enuresis include dairy products, chocolate, and citrus fruits and juices.25
Behavioral Conditioning. Behavioral conditioning in the treatment of primary nocturnal enuresis is based on the use of a signal alarm device. When the child voids in bed, a moisture-sensing device that has been placed near the genitals is activated and triggers an alarm. This evokes a conditioned response of waking and inhibiting urination.
Various alarm devices are currently available. The alarm is either a sound or a vibratory device. We prefer the vibratory alarm because we have found it to be more effective than the sound devices in waking children. We do not recommend using the alarm with children younger than seven years of age.
Alarm therapy requires a cooperative and motivated child and family. Parental involvement is very important when using alarm devices. Involvement includes recording the child's responses to the device and monitoring his or her progress. Again, use of a diary and a reward system may help reinforce the desired behavior. Parents should be told that this form of therapy will require a long-term commitment as results may not be evident for several months.
Long-term success using signal alarm devices has been reported in approximately 70 percent of children with primary nocturnal enuresis.26 We recommend that children use the alarm devices until they experience three weeks of complete dryness. Relapse rates are higher when the alarm system is discontinued after shorter dry periods. Overall, relapse occurs in 20 to 30 percent of patients. Relapse is certainly not incompatible with restarting alarm treatment, and results are generally good with consistent use.
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TABLE 2
Some Alarm Devices for the Treatment of Primary Nocturnal Enuresis
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Device
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Manufacturer
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Cost*
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Wet-Stop
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Palco Labs
Santa Cruz, Calif.
800-346-4488
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$65.00
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Nytone Enuretic Alarm
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Nytone Medical Products
Salt Lake City, Utah
801-973-4090
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53.50
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Potty Pager
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Ideas for Living
Boulder, Colo.
800-497-6573
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49.95
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Nite Train'r
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Koregon Enterprises
Beaverton, Ore.
800-544-4240
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69.00
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Sleep Dry
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Star Child Labs
Aptos, Calif.
800-346-7283
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45.00
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*--Manufacturers' prices, rounded to the nearest dollar. Shipping and handling charges are not included.
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Another method of behavioral conditioning involves waking the child two to three hours after he or she has gone to sleep, eliciting a conditioned response of waking when the bladder is full. The success rate of this technique is unknown. Most parents who use this technique report having difficulties in gaining their child's cooperation with this program.
Bladder-Training Exercises. It is possible that functional bladder capacity may be reduced in children with enuresis, causing premature bladder emptying during the night.27 As mentioned previously, urodynamic studies have not demonstrated a reduced functional bladder capacity in children with enuresis.20
However, in some children with a small bladder capacity, the use of bladder-retention training during the day may help increase bladder capacity at night. This training is accomplished by having the child hold his or her urine for increasing periods of time. In one study27 of children undergoing six months of bladder-retention training, 66 percent of children reported some improvement, and 19 percent experienced complete resolution of symptoms. Bladder capacity increased significantly in patients who responded to this therapy. However, this is the only study to document such improvements, and results from this study must be validated by more data.
Pharmacologic Therapy
Pharmacologic therapy for the treatment of primary nocturnal enuresis is usually reserved for use in children older than seven years of age. Two approaches to drug therapy can be used. One approach is to increase bladder capacity. The other is to reduce the amount of urine produced by the kidneys. Again, a careful examination and medical history, including a history of previous treatment, should be performed before drug therapy is initiated.
Several medications are available for the treatment of primary nocturnal enuresis (Table 3); however, none of these medications cures enuresis. Instead, they provide a stopgap measure until the children are able to wake on their own during the night to void. Parents should not expect immediate results and should be made aware of the potential side effects of the medications. Because both the parent(s) and the physician are generally reluctant to use medication as a first-line treatment, drug therapy is often reserved for use in children who have shown no success with other treatment modalities. In some cases, however, family circumstances and/or the need for quick symptomatic relief may make drug therapy a valuable first-line option.
TABLE 3
Pharmacologic Therapy for the Treatment of Primary Nocturnal Enuresis
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Drugs
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Cost*
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Imipramine (Tofranil) 30 tablets, 25 mg, $14.00; generic: 30 tablets, 25 mg, $1.75 to $2.00
Oxybutynin (Ditropan) 90 tablets, 5 mg, $44.00; generic: $27.00 to $33.25; 480 mL, generic: $40.00 to $53.00
Hyoscyamine (Levsin) 90 tablets, 0.125 mg, $34.25; generic: 90 tablets, $11.75 to $14.00
Levsinex Timecaps 60 capsules, $43.75; generic: 60 capsules, $14.25 to $15.00†
Desmopressin acetate (DDAVP) 5-mL nasal spray, $121.25‡; 0.1 mg, 60 tablets, $96.75; 0.2 mg, 60 tablets, $156.25
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*--Estimated cost to the pharmacist based on average wholesale prices, rounded to the nearest quarter dollar, in Red book. Montvale, N.J.: Medical Economics Data, 1997. Cost to the patient will be higher, depending on prescription filling fee.
†--Check product for generic equivalency.
‡--Not available in generic form.
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TABLE 3
Pharmacologic Therapy for the Treatment of Primary Nocturnal Enuresis
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Drugs
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Cost*
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Imipramine (Tofranil)
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30 tablets, 25 mg, $14.00; generic: 30 tablets, 25 mg, $1.75 to $2.00
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Oxybutynin (Ditropan)
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90 tablets, 5 mg, $44.00; generic: $27.00 to $33.25; 480 mL, generic: $40.00 to $53.00
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Hyoscyamine (Levsin)
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90 tablets, 0.125 mg, $34.25; generic: 90 tablets, $11.75 to $14.00
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Levsinex Timecaps
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60 capsules, $43.75; generic: 60 capsules, $14.25 to $15.00†
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Desmopressin acetate (DDAVP)
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5-mL nasal spray, $121.25‡; 0.1 mg, 60 tablets, $96.75; 0.2 mg, 60 tablets, $156.25
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*--Estimated cost to the pharmacist based on average wholesale prices, rounded to the nearest quarter dollar, in Red book. Montvale, N.J.: Medical Economics Data, 1997. Cost to the patient will be higher, depending on prescription filling fee.
†--Check product for generic equivalency.
‡--Not available in generic form.
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No pharmacologic method cures enuresis, but pharmacology can be used as a stopgap measure until patients are able to wake and void on their own.
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