Urodynamic Studies

Urodynamic tests are used to diagnose patients who have urinary incontinence or other lower urinary tract symptoms. Urodynamic tests are used to measure:

• Nerve and muscle function
• Pressure around and in the bladder, which may come from a prolapse
• Flow rates and other factors

These tests look at how well the bladder, sphincters, and urethra are storing and releasing urine.

Most urodynamic tests are meant to discover how well the bladder is holding urine and how urine is emptied. The bladder should be able to let out urine in a steady manner so that it empties all the way. Your bladder might contract (squeeze) without you wanting it to, which can lead to urine leakage.

Urodynamic tests include:

• Cystometry, leak point pressure measurement and pressure flow study
• Pressure flow study
• Uroflometry
• Postvoid residual measurement

Uroflometry

Another test that measures how much and how quickly you urinate is uroflometry. For this test, you will have a full bladder to begin with. You’ll be asked to urinate into special equipment that will allow measurements to happen. A computer is used to automatically measure the amount and flow rate, creating a graph that shows any changes. Test results will let the A/Prof Mahmoud know if you have weak bladder muscles or some kind of blockage.

Postvoid residual measurement

The post-void residual measurement test measures the amount of urine left in your bladder after you empty it. This can be measured with ultrasound equipment that uses sound waves to create a picture of the bladder. Postvoid residual can also be tested by using a catheter that is placed into the urethra and then into the bladder to remove the excess urine. A post-void residual of approximately 150mL or more is a sign that the bladder is not emptying completely, but this can vary depending on your specific situation. 

The tests do not require any special planning. When A/Prof Mahmoud performs your urodynamic test, he will fill the bladder during the procedure. Just prior to the procedure, we will ask you to empty your bladder in the toilet.