Urodynamics
Bladder function testing, or Urodynamics, is a test that provides information about the lower urinary tract and its ability to store and empty urine. This test is useful in diagnosis and planning treatment for a variety of urinary problems including incontinence (involuntary loss of urine), overactive bladder, voiding dysfunction (trouble emptying the bladder), urinary retention (inability to pass any urine at all) and neurogenic bladder (urinary dysfunction related to diseases of the nervous system).
Why do we do this test?
The purpose of urodynamics is to obtain information on how the lower urinary tract is working. Taking a look ( using cystoscopy or with imaging) on the provides part of the picture - these tests only tell us a little bit of what is actually happening.
The bladder has 2 primary functions, to store urine and then to empty it out. Urodynamics evaluates if the bladder is doing its job properly.
What does the test involve?
In order to measure the pressures and volumes a special computer machine is used to fill the bladder and measure flows as well as pressures. This is done by placing catheters into the bladder through the urethra and into the rectum. The test typically takes 30-60 minutes area
What is measured during a urodynamic test?
The test has a number of different components.
Uroflow: in this part of the test, the patient is asked to urinate into a device that measures the flow rate and volume of urine. This is typically followed by a scan to determine if the bladder empties to completion.
Cystometrogram: This part of the test is meant to replicate how the bladder fills. During filling the bladder is meant to remain 'quiet' (to NOT spasm/contract) and to fill under low pressures to a good capacity ( usually about 400 mL)
Pressure flow study: this part of the test is meant to determine how the bladder empties. The bladder should empty to completion under relatively low pressures.if the bladder does not empty it can be the consequence of an issue with the strength of the bladder muscle itself (a problem with the 'motor') or that the outflow tract (the 'pipe') is too tight - there are a number of reasons for this.