Enuresis

Following is a summary of the Spanish guidelines for the management of primary monosymptomatic nocturnal enuresis (bedwetting with no daytime urinary symptoms in children older than 5 years).

Some important definitions:

  1. Expected bladder capacity: Age +1 (in ounces). A 5-year old bladder capacity should be 6 ounces for example. To convert to milliliters, multiply ounces by 30.
  2. Nocturnal polyuria: voiding more than 130% of the expected bladder capacity overnight. For a 5-year old, that would be 6 ounces * 1.3 = 7.8 oz, or 234 ml.

Three mechanisms are thought to be responsible for nocturnal enuresis (NE):

  1. Nocturnal polyuria
  2. Bladder problem (overactivity) — usually related to constipation.
  3. Deep or abnormal sleep

Before treating NE, the following should be ruled out:

  1. Daytime urinary symptoms
  2. Secondary enuresis (NE caused by another medical problem)
  3. Other medical problems such as sleep apnea (snoring) or mental issues like ADHD.

Evaluation

With regards to the physical exam, the genitals are checked for obstructive problems and the back for signs of spinal dysraphism.

It is important to rule out glucosuria or proteinuria with a urine analysis. A renal ultrasound is not necessary for the evaluation of monosymptomatic NE.

A 2-day voiding diary provides information about daytime urinary symptoms, bowel movements, and frequency of NE.

 

Treatment

General Measures (which do not cure or stop NE but are still recommended):

  1. Good hydration
  2. No caffeinated beverages
  3. Avoid milk and sugary drinks at dinner and before bedtime.
  4. Time voiding q 2-3 hrs during the day
  5. No pull-ups (The guideline does not say why but recommends using alternative ways of containing the urine).
  6. Address constipation
  7. Physical activity
  8. Push fluids in the early part of the day
  9. Void before bedtime

Rewards should be given for cooperating with the treatment plan and not for waking up dry.

Bedwetting alarm

This is the video that I use in the office to explain to parents what the bedwetting alarm is and how to use it.  The alarm works in 2/3 of children, and up to 1/3 will have a recurrence.

The guideline recommends a follow up the day the child will start using the alarm to go over technical issues and 2-3 weeks later to check on things. If there is no success after 2-3 months, it is unlikely to work with further use. For the children in which the alarm works, “overlearning” — increasing fluids right before bedtime with the continuation of the use of the alarm — can decrease recurrences.

This is the alarm that I recommend to my patients for the only reason that they can order it online, it works — I used it on my daughter –, and is cheap.

Desmopressin

Although most children will have a partial response to it, only about a third will have a complete response. The drug is taken 1 hr before bedtime with no more fluids after that. If successful, the drug is stopped every 3 months to see if the patient still needs it. If the medicine did not work in one week, it will not work.

The drug should not be given when the child is sick –especially with GI issues.

 

Other drugs

Oxybutynin and anticholinergics

Some doctors start patients on the maximum dose of desmopressin (0.6 mg) and oxybutynin and then start gradually decreasing the doses/medicines if the patient responds. The combination works better than desmopressin alone.

Imipramine

Half of the patients with NE respond to imipramine, but due to side effects, the medicine is last resort.

 

Conclusion

NE is common with 15% of 6-year olds affected and up to 2% of young adults. Although it goes away on its own in most, treatment is recommended for those who want it for any reason — sleepovers, self-esteem, or to save on laundry.

The evaluation is limited to ruling out breathing problems –snoring– that could benefit from surgery (Tonsils/adenoids), and psychological problems like ADHD.

Some believe constipation is the one and only cause of enuresis. I discussed that before here.

General measures such as drinking more during the day, voiding regularly, avoiding caffeinated beverages and milk at night, voiding before bedtime, and not using diapers, are widely recommended but unlikely to stop NE.

The alarm is probably the best treatment but it can be a pain for everyone involved, with up to 1 hr of sleep lost per night. The child has to be really mature for the alarm to work.

Desmopressin completely eliminates enuresis in about a third of patients. Adding oxybutynin increases response rates. If the family prefers to start with medicines, one approach is to prescribe the max dose of desmopressin plus oxybutynin with subsequent tapering off successful cases and complete discontinuation after a week in unsuccesful ones.

 

 

 

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