Enuresis

Definition
Enuresis (DSM-IV Classification)

Repeated voiding of urine into bed or clothes
1. Involuntary or intentional
Clinically Significant criteria (one of the following)
1. Twice weekly for at least 3 consecutive weeks
2. Significant distress
3. Impaired functioning
Age 5 years or older
Secondary cause not present
1. Medication (e.g. Diuretics)
2. Diabetes Mellitus
3. Spina bifida
4. Seizure Disorder

Categories
Enuresis

Primary or Secondary
1. Primary Enuresis (80%)
  1. No history of urinary continence for more than 6 months
2. Secondary Enuresis (20%)
  1. Enuresis recurs after 6 months of urinary continence
  2. Typically associated with new psychosocial stressors or medical or behavioral condition
Monosymptomatic or nonmonosymptomatic
1. Monosymptomatic Enuresis
  1. Nighttime bed wetting without other symptoms
2. Non-monosymptomatic Enuresis (associated with more significant abnormality)
  1. Daytime lower urinary tract symptoms (e.g. urgency, frequency, incomplete emptying) or
  2. Daytime Incontinence or
  3. Dysuria or
  4. Holding maneuvers (e.g. leg crossing)
Timing
1. Nocturnal Enuresis only (80%)
2. Nocturnal and diurnal (20%)

Epidemiology
Prevalence of Enuresis

Age 2 years: 82%
Age 3 years: 49%
Age 4 years: 26%
Age 5 years: 15-25%
Age 7 years: 5-10%
Age 12 years: Boys: 8%; Girls 4%
Age 18 years: Boys: 1%: Girls rare

Pathophysiology

Maturation delay
1. Enuresis Prevalence decreases with age
2. "Bladder full" signal does not yet work
  1. Inability to awaken in response to the stimulus of a full Bladder
Other predisposing factors
1. Excessive nighttime urine production
2. Decreased Bladder functional capacity
Strong association with Family History
1. Gene markers on Chromosome 5, 12, 13 and 22
2. Both parents with Enuresis: 77% chance of Enuresis
3. One parent with Enuresis: 44% chance of Enuresis
  1. Relative Risk if Father with Enuresis: 7.1
  2. Relative Risk if mother with Enuresis: 5.2

Causes
Secondary (3%)

Bladder Dysfunction or unstable Bladder (3-5%)
Medically treatable
1. Urinary Tract Infection, especially in girls (18 to 60% of cases)
2. Diabetes Insipidus
3. Diabetes Mellitus
4. Hyperthyroidism
5. Sickle Cell Anemia
6. Fecal Impaction or Constipation often with comorbid Encopresis and treatment resistance (33-75% of cases)
7. Overactive Bladder or dyfunctional voiding (<41% of cases)
Surgically treatable
1. Ectopic Ureter
2. Lower Urinary Tract Obstruction
3. Neurogenic Bladder (e.g. Spinal Dysraphism)
4. Bladder calculus or foreign body
5. Obstructive Sleep Apnea secondary to large adenoids (10 to 54% of cases)
Psychiatric illness (in only 20%)
1. More common in enuretic girls
2. Suggested by Enuresis both night and day
3. More likely if Enuresis persists in older child
Regressive Enuresis (occurs after being dry)
1. Associated with stressful environmental event

History

Voiding History
1. Consider a two week voiding diary
2. Does child meet DSM-IV criteria for Enuresis above?
3. Has the child ever been dry for a 6 month period? (primary or secondary)
4. Is there daytime Enuresis? (complicated Enuresis)
5. Characterize the Enuresis
  1. How many days per week?
  2. How many times per night?
  3. What time of night does Enuresis occur?
Urinary Tract Infection symptoms
1. Dysuria
2. Urinary urgency or Urinary Frequency
Bowel habit changes
1. Infrequent or difficult stool passage
2. Encopresis
3. Constipation with hard stools at a frequency of <4 times per week
Functional Bladder disorder or neurogenic Bladder signs
1. Frequent Urination with voids >7 per day
2. Urine urgency
3. Withholding urine until last minute
4. Wets more than once nightly
5. Small volumes from incomplete emptying
6. Dribbling, straining to obtain even a weak urine stream
Nocturnal Polyuria
1. Enuresis on only a few nights per week
2. Voids large volumes when Enuresis occurs
3. Soaked absorbant underpants or voids large first-morning void despite Enuresis?
4. Excessive water intake prior to bed?
5. Weight loss associated with polydipsia and Polyuria (Diabetes Mellitus)?
Other related history
1. Birth complications
2. Neurologic disorders (motor disorders, Learning Disorders, Developmental Delay)?
3. Genitourinary surgeries
4. Family History of Enuresis
5. Behavioral problems
6. Snoring and Daytime Somnolence (Obstructive Sleep Apnea)
7. Sickle Cell Anemia

Examination

Height and weight
1. Evaluate for Growth Delay or Failure to Thrive (e.g. Diabetes Mellitus, Chronic Kidney Disease)
Head and neck exam
1. Evaluate for Tonsillar Hypertrophy (and consider enlarged adenoids) suggestive of pediatric Sleep Apnea
Abdominal and flank exam
1. Costovertebral Angle Tenderness (CVA Tenderness)
2. Abdominal masses
3. Bladder enlargement
Genitourinary exam and Rectum
1. Males
  1. Hypospadias, meatal stenosis, Phimosis
2. Females
  1. Labial adhesions
3. Sexual abuse signs
  1. Excoriations at the perineum or perianal region
  2. Prepubertal Vulvovaginitis
4. Rectum
  1. Fecal Impaction or signs of soiling (Constipation, Encopresis)
  2. Decreased sphincter tone (may be comorbid with neurogenic Bladder)
Back exam
1. Dimple, hair tuft, Lipoma or other skin findings in the midline superior to the gluteal cleft (Spinal Dysraphism signs)
Neurologic Exam
1. Gait Evaluation for neurologic deficits
2. Lower limb motor weakness or reflex abnormality

Labs

Urinalysis
1. Signs of Urinary Tract Infection
2. Urine Specific Gravity
3. Urine Glucose
Other labs to consider
1. Fingerstick Blood Sugar
2. Basic metabolic panel including Renal Function

Imaging

Consider as indicated
Renal Ultrasound and Bladder Ultrasound
1. Indicated for suspected urinary tract malformation or Chronic Kidney Disease
MRI Lumbar Spine
1. Indicated for suspected Spinal Dysraphism

Management
Referral Indications

Non-monosymptomatic Enuresis
Recurrent Urinary Tract Infection
Urinary tract malformations
Prior pelvic surgery
Neurologic disorders (e.g. neurogenic Bladder)
Failure to respond after age 7 years old to adequate trial of bed alarm and Desmopressin
Psychiatric disorder
Dysfunctional voiding (or urinary tract malformation)
Chronic Kidney Disease

Management
General

Discussion topics
1. Reassure parents with age-related norms
2. Counsel family regarding conflict surrounding Enuresis
Assess for organic causes (see above)
1. Complete history and physical with Urinalysis
  1. No further evaluation necessary if normal results
2. Treat reversible underlying causes
  1. Constipation
    1. Consider pediatric gastroenterology Consultation for Encopresis
  2. Acute Urinary Tract Infection
    1. Consider imaging and Consultation for Recurrent Urinary Tract Infection
  3. Obstructive Sleep Apnea
    1. Consult regarding Tonsillar or adenoid hypertrophy
  4. Diabetes Mellitus
3. Obtain Consultation for complicated secondary causes
  1. See referral indications above

Management
Non-Pharmacologic Therapies

Indicated for monosymptomatic Enuresis (no secondary disorder suspected)
Appropriate Toilet Training
1. Scheduled voiding times (especially in evening)
2. Behavior Modification
  1. Bed-Wetting Alarm
    1. Most effective treatment for Nocturnal Enuresis
  2. Visualization techniques
  3. Void just before bedtime
  4. Limit fluids 1 hour before bedtime
  5. Scheduled awakening during night to void
    1. Some experts do not recommend
3. Positive reinforcement system
  1. Charts the child's progress of dry nights
  2. Given stickers on calendar or points per dry night
General Recommendations
1. Enlist support and cooperation of child
2. Older children launder their own soiled clothes
  1. Should not be punishment
  2. Allows child's participation and responsibility
Avoid harmful measures
1. Waking child repeatedly during the night to void
  1. Interferes with sleep
  2. Aggravates child and parent
2. Punishing or shaming the child for wetting the bed
3. Intimidating the child or lowering his self esteem
4. Postponing the child's bedtime to decrease Bedwetting

Management
Pharmacologic Therapies

Try to avoid medications if possible
1. Medications are only effective briefly
2. Drug tolerance is common
3. Symptoms are exacerbated after drug is discontinued
4. Adverse effects are common
5. If used, avoid in under age 6 years
Medications: Primary Nocturnal Enuresis
1. Imipramine (or Desipramine)
  1. Typical dose: 25 mg nightly
  2. Not first line due to cardiac arrhythmia risk
  3. As effective as Desmopressin
  4. Higher rate of adverse effects compared with dDAVP
2. dDAVP (Desmopressin, ADH)
  1. Typical dose: 0.2 mg
  2. Restrict fluid intake 1 hour before taking dDAVP
  3. Nasal form is no longer approved for Enuresis due to Hyponatremia (water Intoxication)
    1. Can also occur with oral form, but less commonly
    2. Robson (2007) J Urol 178(1):24-30. [PubMed]
  4. For intermittent use on overnights or summer camp
  5. Effective in children with nocturnal Polyuria (but high relapse rate)
    1. Not effective in low nighttime Urine Output or small Bladder capacity
Medications: Urge Incontinence or Diurnal Enuresis
1. Oxybutynin (Ditropan)
  1. Dose: 2.5 to 5 mg orally three times daily
  2. Anticholinergic side effects
  3. Consider in combination with dDAVP

Course

Annual resolution rate of Nocturnal Enuresis: 15%

References