What is DTUI?
Until the stage of total voiding control, the child urinates without the effective participation of the cerebral cortex. And what does that mean? Normally, in young children, after bladder filling, there is a message sent to the medullary levels which, in turn, sends a message back ordering urination. It is therefore said that at this stage, the child urinates involuntarily. With growth, the urinary pathways mature neurophysiologically and the involuntary contractions of the bladder cease. As a result, the cerebral cortex begins to exercise control over when the bladder empties. The child becomes socially aware and knows not to urinate in their pants. Therefore, in general, from the age of 3 to 5, if the child feels their bladder is full and it is convenient to urinate, then there is a facilitating message in the brain ordering urination. If it's not convenient at the moment, then there is an inhibitory message for urination and the child waits for the best moment to urinate.
However, for reasons as yet unknown, there seems to be a delay in the neurophysiological maturation of the micturition pathways in some children. As a result, involuntary bladder contractions remain until a stage when the bladder should be filling at rest. These involuntary contractions cause some children to urinate in their pants, completely emptying their bladder. However, most children voluntarily contract the external urethral sphincter to prevent urinary leakage and often assume postures such as crossing their legs or squatting using their heels to compress the urethra and prevent urine leakage. This, despite appearing to be of no consequence, can cause intense impairment of the urinary system. High pressures can be generated inside the bladder which can increase the thickness of the bladder wall, cause bladder diverticula, cause dilation and kidney damage.
This whole disorder is called lower urinary tract dysfunction, because it concerns functional alterations of the urethra and bladder, which make up the lower urinary tract, while the ureter, pelvis and kidneys correspond to the upper urinary tract.
How is lower urinary tract dysfunction classified?
UTID is classified into disorders of the urinary storage phase and the emptying phase.
In storage phase disorders, also known as bladder hyperactivity, there are involuntary contractions of the bladder, the child tries to hold in the urine and avoid losing urine in their pants, but there is no change in urination. Urination is coordinated, the urinary stream is good and there is no urinary residue inside the bladder after urination.
However, in emptying disorder, known as voiding dysfunction, urination does not occur in a coordinated manner. When the bladder contracts, instead of the urethra relaxing, the urethral sphincter contracts, which means that urination is often under high pressure and unsatisfactory, with a weak urinary stream, abdominal straining and a significant urinary residue in the bladder after urination.
What is the relationship between lower urinary tract dysfunction and reflux?
Around 15 to 50% of children with vesico-ureteral reflux have UTID. Of older children with urine infections, 70-100% have UTID. Reflux is also closely associated with urine infection.
What is the relationship between lower urinary tract dysfunction and urinary infection?
The vast majority of children over the age of four with recurrent urinary tract infections have UTIs. In up to 50% of cases, vesico-ureteral reflux is also associated. It is very important to treat UTID and avoid urinary infection, since UTID is a cause of infection and infection can cause or worsen the symptoms of UTID. In addition, due to the high intravesical pressures generated by uncoordinated urination in the presence of infection, there may be a greater risk of kidney damage. In cases of children without reflux and recurrent infection, we have kept them on continuous low-dose antibiotic prophylaxis. Up to three months of age we use cephalexin and after three months we use nitrofurantoin, both at ¼ of the therapeutic dose. In the case of UTID and reflux, we have used sulfamethoxazole-trimethoprim in the morning and nitrofurantoin at night, also ¼ of the therapeutic dose.
What is the relationship between lower urinary tract dysfunction and constipation?
Constipation is present in around 50% of cases of children with UTID. It is known that stool retention worsens bladder function and facilitates the occurrence of urinary infection. Constipation should therefore be treated in conjunction with UTID.
How is lower urinary tract dysfunction treated?
There is evidence that the mainstay of treatment for UTID is behavioral change. The following guidelines should be followed:
Any child who does not yet have voluntary urination, i.e. has not yet undergone voiding training, with a urinary infection, even in the first episode, even if they are afebrile, should be investigated for reflux. Those with afebrile urinary infection after voiding training do not need to be investigated for reflux. Investigation for reflux is done with voiding cystourethrography. This test is extremely important and should not be missed. A probe is passed into the bladder, through which iodinated contrast is administered. Some X-rays are taken, which will assess whether there is any backflow of urine into the ureters and kidneys. If there is reflux, children are usually followed up with radioisotopic cystourethrography annually or every 2 years.
- Urinate at regular intervals 5 to 6 times a day
- Drink plenty of fluids during the day
- Do not hold back urine when the urge to urinate is imminent
- Correct urination posture (see photo below): the child should keep the soles of their feet supported either on the floor or on a support, in the case of high toilets; their spine should be curved slightly forward; their hand should be placed on their stomach and their stomach should be relaxed ("asleep"); while they are urinating, they should sing a song or count numbers; after they have finished urinating, they should count to 10 so that all the urine has time to come out of the bladder.
In many cases, these measures do not improve the child's symptoms. Therefore, other methods often have to be used.
The treatment of UTID will vary depending on whether there is an overactive bladder or dysfunctional urination.
Overactive bladder, when there is urgency to urinate and common urinary leakage through clothing during the day, can be treated with anticholinergic medication, such as oxybutynin. The chance of success is around 70%. However, these drugs sometimes have some minor undesirable effects, such as dry mouth, constipation and heat intolerance. These effects improve quickly when the medication is stopped.
Another treatment that has emerged as an excellent method is electroneuro-stimulation. Surface electrodes are placed in the parasacral region and the nerves that control the bladder are activated, improving symptoms in around 90% of cases. There is no pain and the child feels a slight tingling sensation in the stimulated area. Our group, CEDIMI, changed the electroneuro-stimulation regimen from one to two hours a day for months to a short-term regimen. In our scheme, the child is stimulated 3 times a week, with 20-minute sessions. This short-term method has the advantage of maximizing treatment with the most appropriate current intensity and closer contact with the therapist, as well as shorter duration and greater patient compliance. This pioneering method devised by our group is already being carried out in other centers in Brazil and around the world.
If children with overactive bladder do not improve with the methods described above, botulinum toxin can be injected into the bladder.
In dysfunctional urination there is an incoordination between the contraction of the bladder and the relaxation of the urethral sphincter. In this case, the most effective treatment method is biofeedback. In this case, using computer games, the child is shown how to relax the muscles of the urethra during urination.