Enuresis (bed wetting)

Enuresis Overview:

• Enuresis refers to Involuntary loss of urine during sleep, occurring at least twice a week in children over 5 years for at least 3 months.
• Attaining night time continence is a normal developmental process, with significant age variation. There is a strong genetic tendency to bedwetting
• Enuresis is common and generally causes no lasting problems. Typically treatment is not started before age 6 years, as there is a high rate of spontaneous resolution
• Most children who wet the bed have no significant underlying physical or emotional problems.  However, many will feel embarrassed or ashamed and suffer from decreased self-esteem, particularly as the child gets older 
• For most children, enuresis is only seen as a problem when it interferes with their ability to socialise with friends (for example overnight stays or school camps). If the enuresis is infrequent and/or not distressing to the child or parents, treatment is not indicated
• Daytime bladder control and coordination usually occurs by 4 years of age, however night-time bladder control typically takes longer and is not expected until a child is 5–7 years old.  At 4 years of age, nearly 1 in 3 children wets the bed, but this falls to about 1 in 10 by age 6

types

• Primary: Child hasn’t been dry for at least 6 months
• Secondary: Onset after 6 months of dryness.
• Monosymptomatic: Nocturnal wetting without daytime incontinence
• Non-monosymptomatic: Correlated with daytime symptoms.

Epidemiology:

• Prevalence similar across cultures, varies with age:
  • 15% at age 7
  • 10% at age 10
  • 2% in adolescents
  • 0.5 to 1% of adults
• More common in boys (3:1 ratio), but ratio decreases with age
• Additionally, 20 to 30% of patients with enuresis also suffer from at least one psychological, behavioral, or psychiatric disorder, a rate twice as high as that of the general population.
• The most common of these comorbidities is attention deficit and hyperactivity disorder
• Other comorbid conditions in this category include autism spectrum disorder, oppositional defiant disorder, and mood disorders

Associated Conditions:

• Constipation
• Urethral obstruction
• Ectopic ureter
• Cystitis
• Diabetes insipidus
• Disorders of sleep arousal
• Small bladder capacity
• Overactive bladder

Pathophysiology:

• genetic component
  • studies suggest that inheritance of the condition is in an autosomal dominant pattern with 90% penetrance
• Nocturnal Polyuria:
  • Associated with vasopressin deficiency or circadian release alterations.
  • Leads to increased urine production at night.
• Bladder Dysfunction:
  • More common in patients with daytime incontinence.
  • Manifests as:
    • Diminished bladder capacities.
    • Abnormal urodynamics.
    • Nocturnal detrusor hyperactivity.
  • Can be linked to constipation, causing bladder distortion.
• High Arousal Thresholds:
  • Difficulty waking up due to:
    • Disturbed sleep (e.g., obstructed airway).
    • Contractions in the bladder.
  • Can be a cause or result of enuresis.
• Maturational Delay Hypothesis:
  • Supported by:
    • Higher prevalence of motor clumsiness.
    • Perceptual dysfunction.
    • Speech disturbances in children with enuresis.

History

Much of the history should focus on voiding habits

• Onset of bedwetting
  • if acute — last few days to weeks — consider whether this is a presentation of systemic illness
• Has the child previously been dry at night without assistance for 6 months?
  • If so, consider possible medical, emotional, or physical triggers
  • The presence of unexplained persistent secondary enuresis despite adequate management should prompt specialist referral
• Presence of day-time symptoms
  • frequency, urgency, polyuria, dysuria/recurrent UTI, poor urinary stream/straining, leakage)
  • If daytime symptoms predominate, consider treating before bedwetting
• Bedwetting pattern and trend
  • nights per week/month
  • amount
  • time of night
  • arousal from sleep
• Fluid intake
  • evening fluid intake
  • caffeine containing drinks
  • polydipsia
• Bowel habit
  • constipation/soiling
• Sleeping arrangements and routine
  • including own bed/bedroom
  • snoring and disturbed sleep
• Medical History:
  • consider other co-morbid factors which may exacerbate or prolong nocturnal enuresis;
  • developmental or behavioural problems
  • diabetes mellitus
  • sleep apnoea 
• Family history of bedwetting or renal problems
• Social history;
  • family capacity and motivation to engage in treatment
  • social difficulties (vulnerable child/family)
• Development history
  • Patients should have screening for psychological or behavioral disturbances, including attention deficit and hyperactivity disorder and learning disabilities, and obtaining a developmental history is also necessary

Examination

• Height, weight, BP — poor growth / loss of weight / hypertension
• Abdomen — distended bladder, faecal mass
• Inspection of external genitalia (and perianal area if constipation also present) 
• Lower Back/Spine – exclude occult spinal dysraphism or tethered cord (asymmetric/deviation of gluteal cleft) 
• Assessment of lower limb neurology

Evaluation:

• AS PER RCH GUIDELINES:
  • Dipstick urinalysis is not required in primary enuresis.
  • Consider if red flags apparent.
  • Further imaging or blood tests are not routinely recommended in enuresis
• Urinalysis MAY SHOW:
  • alterations in specific gravity in diabetes insipidus
  • glycosuria in case of diabetes mellitus
  • presence of nitrites leukocyte esterase, leukocytes, or bacteria in case of infection

Treatment/Management:

• General Advice
  • Constipation, if present, should be adequately managed before addressing enuresis
  • Advise on normal bladder function and the pathogenesis of enuresis, including the genetic tendency.  
  • REASSURANCE: common problem effecting their peer group and they should not be embarrassed
  • Encourage regular fluids and toileting throughout the day (eg during school break times) and just before bedtime
  • Advise against fluid restriction, but eliminate caffeinated beverages in the evening
  • Both parent and child must be motivated before starting behavioural interventions
• Bedwetting (Pad and Bell) Alarms
  • Considered the most useful and successful initial way to treat bedwetting – good long-term success and fewer relapses than medication
  • Require a supportive and helpful family and it is important to communicate to families that it may take 6–8 weeks to work
  • Parent instruction videos available on Kids Health Information
  • Generally recommended in children from 6–7 years of age, depending on their physical ability, maturity and motivation
  • Mild to moderate intellectual impairment does not preclude treatment and in hearing impaired children consider using a vibrating alarm
  • Not suitable if the carer is experiencing emotional difficulty, expressing anger or blame toward the child, or is unlikely to cope with the additional burden of a bedwetting alarm and sleep disruption in the household
  • Children should be ‘in charge’ of their alarm and may need to be woken initially to turn the alarm off themselves. It is critical for success of alarm therapy that the child is fully awake during the process of going to the bathroom
  • Reward systems can be useful during alarm therapy to reward behaviours such as waking or going to the toilet when the alarm goes off (Not for dry nights per se)
  • If a child is showing early signs of response after 4 weeks, continue treatment until 2 weeks of uninterrupted dry nights are achieved
  • Discontinue treatment if no early signs of response within 4 weeks 
  • If there is incomplete dryness after 3 months, reconsider if ongoing treatment is appropriate or a further trial of the alarm in 3–6 months
• Overlearning
  • Once dryness is achieved for 2 weeks or more, consider introducing “overlearning” — to over condition the bladder. Encourage the child to drink extra fluids in the hour before bedtime, providing a greater challenge to remaining dry, which may reduce the rate of relapse
• Behavioural Therapy: Lifting, Walking & Waking
  • Neither lifting (carrying a child to the toilet with an effort not to wake them) nor waking and walking the child to the toilet will promote long-term dryness
  • Waking a child by parents or carers, either regularly or randomly, is only a short-term method of managing bedwetting.  A young person who self-instigates waking (using a mobile phone alarm or an alarm clock) may be a useful strategy

Pharmacological Therapy 

• Note: Tricyclic medications are no longer recommended.  
• They are less effective than other therapies and have a higher risk of adverse events

Desmopressin: Minirin^TM melt/tablet

• Indicated when:
  • alarm therapy has failed or is not suitable
  • if rapid onset/short-term improvement is a priority of treatment
• Relapse rates are high when withdrawn, (60–70 percent)
• Evaluate maturational appropriateness of use for children <7 years of age
• Restrict fluid from 1 hour before the dose until at least 8 hours after the dose. Desmopressin is contraindicated for children who can’t control fluid restriction
• Assess response after 4 weeks to determine continuation of treatment (if no response consider cessation).
• Withdraw for at least 1 week every 3 months to assess for relapse and ongoing need for medication. 

DOSING:

• Sublingual
  • >6 years, sublingual, initially 120 micrograms at bedtime
  • if needed, after 1–2 weeks increase to a maximum of 240 micrograms at bedtime
• Oral
  • >6 years, oral, initially 200 micrograms at bedtime
  • if needed, increase to 400 micrograms at bedtime

Intranasal route is not recommended due to higher risk of hyponatraemia

Prognosis:

• Spontaneous resolution common, but associated with emotional and physical abuse, low self-esteem, poor academic performance.

Complications:

• Negatively impacts quality of life, socialization, leads to low self-esteem, mood problems, high stress.
• Effective treatment improves quality of life.

Consider referral to a general paediatrician or continence service when

• Red flags are present
• Persistent enuresis with failure of an enuresis alarm
• Day-time enuresis or combined day/night enuresis after exclusion or treatment of a UTI and constipation
• History of recurrent urinary tract infections
• Comorbidities such as type 1 diabetes, physical or neurological problems
• Substantial psychological or behavioural problems (consider mental health referral, paediatrician and/or child protection services if significant concern exists)