*3.5.1 Uroflowmetry*

Uroflowmetry is the simplest form of urodynamics. As a non-invasive method, it is ideal for pediatric needs (**Figure 1**). It enables the examination of the function of the detrusor and the sphincter in the voiding phase of the child's micturition.

**Figure 1.** *Uroflowmetry.*

The uroflowmeter was first described in the 1950s [23]. The method can be applied from the fourth year of life of a child with established micturition control. In order to get reliable results, it is necessary for the child to urinate at a capacity that is not less than 50% nor more than 115% of the bladder capacity expected for age [4]. In addition, it is necessary to repeat examination to make the result accurate and reliable.

The method consists in urinating the patient in a uroflowmeter, continuously measuring the urine flow rate (ml/s) and at the same time graphically showing the curve. The placement of two superficial EMG electrodes on the perineum enables the recording of the activity of the PFMs in the micturition phase. In this way, significant data are obtained, especially in children with DV. The uroflowmetry curve is of the staccato or interrupted type with an increase in the EMG activity of the PFMs during urination (**Figure 2**).

Upon completion of this study, an ultrasound examination of the bladder is performed to determine post-void residual urine. In a child aged 7 to 12 years, residual urine greater than 20 ml or 15% of the bladder capacity expected for age is considered elevated [4]. Residual urine that is larger than 10 ml or 6% of bladder capacity expected for age during several measurements is also considered elevated [4].

## *3.5.2 Cystometry*

Cystometry is the only method by which bladder function can be examined directly and in detail. The method is invasive. In order to obtain the data necessary *Rehabilitation Protocols for Children with Dysfunctional Voiding DOI: http://dx.doi.org/10.5772/intechopen.98573*

**Figure 2.** *Interrupted uroflowmetry curve with increased pelvic floor EMG activity during voiding.*

for urodynamic analysis of bladder function, simultaneous measurement of pressure in the bladder, urethra and abdomen is required. This continuous measurement of detrusor pressure and sphincter activity during bladder filling and emptying allows an accurate diagnosis to be made for most lower urinary tract disorders.

In children with DV, cystometry is indicated only in certain cases, primarily because the diagnosis is made using non-invasive methods. It should be performed only in severe cases of DV, which should be differentially and diagnostically distinguished from neurogenic bladder with detrusor sphincter dyssynergia, suspicion of Hinman-Allen syndrome and DV resistant to the applied therapy.
