Kristy is a 5-year-old girl; her mother has brought her in because she has started kindergarten. She has been invited to have a sleepover at a family friend’s house; however, she still wets the bed most nights of the week and wonders how to manage this.
Attaining continence – both daytime and nighttime – is a developmental milestone with a significant normal variation affected by genetic and environmental factors.
At five years of age, approximately 15% of children continue to experience nocturnal enuresis (more commonly known as bedwetting). Every year beyond this, there is spontaneous resolution in ~15% of affected children (although it should be noted that the longer the duration of bedwetting, the lower the likelihood of spontaneous resolution).
Boys are more commonly affected than girls (2:1), and there is a strong family predisposition (both parents = 77%, single parent = 43%). Only one-third of those affected will seek medical attention.
What is nocturnal enuresis?
Nocturnal enuresis is episodes of urinary incontinence during sleep in children ≥5 years of age. It may be further subdivided into monosymptomatic (uncomplicated) and non-monosymptomatic (complicated or polysymptomatic).
- Monosymptomatic: incontinence is present without other symptoms of lower urinary tract/gastrointestinal tract
- Non-monosymptomatic: incontinence associated with other symptoms including but not limited to
- Polyuria/oliguria (8/3 times per day respectively)
- Urgency, hesitancy, intermittency
- Straining/holding manoeuvres
- Weak stream, dribbling
- A feeling of incomplete emptying
- Pain
When episodes additionally occur during the day, it is more appropriately referred to as diurnal enuresis/incontinence.
Incontinence should be classified as primary or secondary.
- Primary: the child has never been dry
- Secondary: the child has been dry for a period of at least six months.
Why does nocturnal enuresis occur?
Nocturnal enuresis results from inappropriate emptying of the bladder by the child and from a mismatch between the bladder’s neurones and the child’s conscious state. This may be due to a multitude of factors, including:
- Maturation delay
- Genetic factors
- Nocturnal polyuria – this may be due to fluid intake, reduced response to antidiuretic hormone (ADH) and/or reduced production of ADH.
- Disturbed sleep in the child (controversial)
- Small bladder capacity
- Detrusor overactivity
These factors may be primary to the child (e.g. genetic factors) or secondary to an underlying condition (e.g. polyuria secondary to undiagnosed diabetes insipidus)
How to evaluate a child with nocturnal enuresis?
It’s almost all in the history – search for red flags!
History:
- Onset
- Previously dry?
- Daytime symptoms (non-monosymptomatic NE)
- Frequency, amount
- Response to episodes
- Fluid habits
- Bowel habits
- Sleep routines
Examination:
- Height/weight
- BP
- Tonsillar hypertrophy/adenoidal facies
- Abdomen (distended bladder, faecal mass)
- Spine
- Lower limb neurology
- Perianal/vulval inflammation (pinworms)
Do you need to do investigations?
Investigations are unnecessary for all patients and should be guided by history and examination. Consider:
- Blood sugar level (fingerprick)
- Urinalysis (m/c/s, electrolytes)
Imaging and blood tests are not routinely indicated.
What are the treatment options?
Important things to remember in treatment:
- Tricyclic medications are not recommended as they are less effective and have a higher risk of adverse effects
- Intranasal desmopressin is not recommended due to the risk of hyponatraemia
- There are high rates of relapse when desmopressin is discontinued (60 – 70%); therefore, it is best used as a short-term measure (e.g.. for going to camp) whilst awaiting spontaneous resolution.
- Desmopressin should not be used in those who are unable to adhere to fluid restrictions (due to the risk of hyponatraemia)
- Treatments with weak evidence include elimination diet, hypnosis, retention control (holding urine for progressively longer periods), biofeedback, acupuncture, scheduled awakenings, caffeine restriction.
Take-home messages
It doesn’t require treatment in those under the age of 6
It is common although undertreated despite treatment options (and families potentially being eligible for funding)
It is usually a primary disorder rather than secondary to an underlying medical condition (although maybe particularly exacerbated by constipation)
Investigations are not routinely required
Treatment requires a motivated family, with behavioural measures and bedwetting alarms being the first line of treatment.
Selected references
Tu, Baskin, Arnhym et al (2019) “Nocturnal Enuresis in Childre: Etiology and Evaluation”. UpToDate.
Tu, Baskin, FAAP (2019). “Nocturnal Enuresis in Children: Management”. UpToDate.
The Royal Childrens Hospital. (2019). “Enuresis – Bedwetting and Monosymptomatic Enuresis.” Melbourne. Retrieved from: https://www.rch.org.au/clinicalguide/guideline_index/Enuresis_-_Bed_wetting_and_Monosymptomatic_Enuresis/
Thiedke C. “Nocturnal Enuresis”. American Family Physician (2003); April 1; 67(7): 1499 – 1506
Ramakrishnan K. “Evaluation and treatment of enuresis”. American Family Physician (2008); August 15; 78(4): 489 – 496.
