Residual urine test

About 20% of patients with pelvic floor symptoms have a voiding dysfunction. In addition, it has been demonstrated that these dysfunctions are associated with increased age and pelvic organ prolapse, which can be accompanied by recurrent urinary tract infections.

It is therefore crucial to assess the volume of residual urine in patients with prolapse, as a sign of a voiding dysfunction. There are different methods for assessing residual urine, which are described as follows:

• The first method is bladder catheterization, which is invasive and bothersome for the patient.
• Another method consists of the bladder scanner, which is an ultrasound device that automatically calculates the volume (anechogenic content) of the bladder. The problem is that when there is an image of an adnexal cyst, the adnexal liquid is registered as bladder content; the same occurs in the presence of ascites, or intra-abdominal free fluid.

Ultrasound is a reliable and safe method. When comparing bladder catheterization with the ultrasonographic calculation of bladder volume using a mathematical formula, Haylen concluded that there is a good correlation. There are many formulas that accurately calculate bladder volume using ultrasound, but, until recently, we had little data regarding the application of these formulas in prolapse patients. In 2014, the Research Group on Pelvic Floor Dysfunctions in Women (GISP in Spanish) showed that residual urine could be measured in the same way in women with advanced prolapse as in patients with no prolapse at all (2); different formulas are applicable, such as those put forth by Haylen, Dietz and Dicuio (please see the section on urinary incontinence).