Urodynamics is a test for finding out how your bladder, sphincter (the muscle around the neck of your bladder) and the urethra (the tube that carries urine out of the body) are working. The test can help find out the cause for bladder problems such as incontinence, or difficulty in passing urine. The test may include X-rays to help your consultant make a diagnosis (Video Urodynamics).
The purpose of a urodynamic study is to find out:
- if your symptoms are due to involuntary contractions (squeezing) or over activity of your bladder muscles
- if you have the bladder capacity we would normally expect
- if your bladder pressure is normal during filling and emptying
Urodynamics are usually performed as an out-patient procedure. The test results will help you and your consultant decide if you need to alter your current treatment, or if you need surgery.
Before you come to hospital you will be asked to keep a voiding diary for three days before you come for your appointment. A voiding diary is a record of how much you urinate. You will need to record what type of fluid you drink, when and how much, and the timing and volume of urine output. You may also be asked to give information about when you experience urgency or urinary leakage.
About the procedure
You will be asked to lie down on a special table and two thin tubes (catheters) are then inserted into your bladder through your urethra.
You may feel the sensation of needing to pass urine as the catheters are put in. Some consultants may use a local anaesthetic gel when inserting these catheters but this is not always needed.
One of the catheters going into your bladder is connected to a sterile water machine and the other is attached to a pressure monitor. The pressure monitor is a special machine that measures how much liquid your bladder can hold and the pressure inside your bladder.
A third catheter is placed in your vagina if you are female, or in your back passage (rectum) if you are male. This is also attached to the monitor and measures the pressure that the rest of your body is putting on your bladder.
Once the catheters are in place, your bladder is slowly filled with sterile water (which may also contain an X-ray contrast dye). Whilst this is happening, you will be asked to tell the consultant when you feel the need to urinate.
During the test you may be asked to cough, strain or squeeze to check how your bladder reacts under pressure. Your consultant may take X-rays during this stage.
Some water may leak out during the test and wet you, but try not to be embarrassed by this. Remember your consultant is trying to find the cause of your bladder problem. Any fluid that leaks out is not urine but the sterile water that has been pumped into your bladder.
You will then be asked to empty your bladder so that the catheters can measure the flow rate and pressure at which you urinate. At the end of the test, the catheters will be removed and you will have privacy to dress.
The test usually takes 30 to 40 minutes and it should not be painful, although it may be uncomfortable at times.
Some people find the prospect of having the test embarrassing, but understanding what will happen during the procedure may help you with this. The staff looking after you will be experienced in performing this test and will try to put you at your ease as much as possible.
After the urodynamic study your consultant will review the results and may discuss them with you after the test, or you may be asked to return for a follow-up appointment with your referring clinician when the results will be explained.
The test will hopefully give a better understanding of your bladder problem and your clinician will offer suitable advice and treatment.
Urodynamics are a commonly performed and generally safe procedure. For most people, the benefits of having a clear diagnosis are much greater than any disadvantages. The chance of complications depends on the exact type of procedure you are having and other factors such as your general health. Ask your urologist to explain how any risks apply to you.
After the catheters are removed you may feel some mild discomfort especially when passing urine. This should settle after a few hours. You may have some blood in the urine. This should settle after a day or so.
To reduce the risk of developing a urinary tract infection you will be given a short course of antibiotics.