Urodynamic Studies

Urodynamic studies are bladder function tests that give important information to your doctor about the nature of your condition. These tests may be done at South Health Campus.

  1. What are they?

    The bladder has two important roles in handling urine, 1) it must first store the urine that comes down from the kidneys, then 2) it must completely expel that urine from the body. Urodynamic studies evaluate how well the bladder performs these two roles. Essentially, the test involves measuring pressure in the bladder during filling and emptying.

    Urodynamic studies are not required for all patients with bladder problems. Some of the more common reasons why urodynamic tests may be requested include:

    • Conservative treatment and/or medications have failed to resolve your problem
    • Your problem is complex, and a precise diagnosis is required
    • Surgery is planned or being considered for your bladder problem
    • You are experiencing problems following surgery
    • You have a neurologic condition that affects your bladder

    Typically, a urodynamic study takes approximately 30 to 60 minutes to complete, and is usually done by a nurse or technician. A doctor may also be present for some tests. There are two types of urodynamic tests, 1) video urodynamics, that involve the simultaneous use of X-ray pictures periodically throughout the procedure, and 2) non-video urodynamics, which do not.

    The concept of a urodynamic test, where small tubes are passed into the body, may be intimidating or distasteful; however, it is important to note that most patients do not find it to be a painful procedure, and the results of the tests are very valuable to your doctor in helping him or her help you.

  2. What are the risks?

    There is little risk associated with a urodynamic procedure. Bladder infections rarely do occur afterward, but antibiotics are not routinely used for everyone. Having said that, if you normally take antibiotics with dental work, or have a history of rheumatic fever, artificial heart valve, heart murmur, or recent placement of a prosthetic device (such as a coronary stent or artificial hip), then you may require antibiotics prior to the procedure. Drinking plenty of fluids after the procedure will reduce the risk of infection, and also help to clear the little bit of blood you might see afterwards.

  3. Preparing for the test?

    If you have collected bladder diaries, where you keep track of your urination frequency and leakage episodes, bring these with you to the test. As with any medical appointment, it is also helpful if you bring your medication list, including the dosages. Take your usual medications on the day of the exam. An exception to this may be your bladder medications if you are on any. The nurse or your doctor will help determine whether you are to stop them beforehand.

    It is important to advise the nurse or your doctor if you normally take antibiotics before procedures, such as dental work. Also let them know if you have any concern that you might have a bladder infection at the time of the procedure. If you have a neurologic condition, it is important for the staff to know what that condition is, and if you need assistance transferring from a wheelchair. Finally, some patients with neurologic problems get headaches or sweating when their bladder gets too full. If you have experienced this, please let someone know.

    If you are having a VIDEO urodynamic test that uses X-rays, you MUST ADVISE YOUR DOCTOR’S OFFICE OR NURSE IF THERE IS ANY CHANCE THAT YOU MAY BE PREGNANT.

    On the day of your procedure, eat a normal meal but do not drink caffeinated beverages (coffee, tea, soda pop). Move your bowels as necessary. Try to arrive to the exam with a comfortably full bladder. This may be difficult for some patients, of course, but as best as possible, try not to empty your bladder for a couple hours prior to the test. If you are finding it difficult to hold your bladder, and are “bursting at the seams” when you arrive, let the staff know, so that they can have you urinate on a special toilet, rather than in the public washroom.

  4. The test

    The urodynamic study begins with an interview with a nurse, technician, and/or doctor. The procedure will again be explained, and a review of your medical history and bladder condition will be undertaken. You will then be asked to change into a hospital gown, or similar attire, and will be taken to the urodynamics room.

    There are two parts to most urodynamic studies, a non-invasive uroflow test, where you simply urinate into a special toilet, and what is called the multichannel study, which is done with catheters in place. If you are normally able to empty your bladder on your own, you will be asked to do so into a special toilet. This is called a uroflow test, and it measures the rate, volume, duration, and pattern of urinating. It also gives the staff something to compare to when you later have to urinate with a catheter in place. After urinating, the nurse will determine how completely you emptied your bladder, by passing a small catheter into it, or scanning with an ultrasound machine. This is called a residual volume assessment. The second part, a multichannel study, is further divided into 2 or 3 parts, to examine bladder filling and emptying. All of this can be done with or without X-ray (when X-ray is used, the study is called a video urodynamic study).

    To begin the multichannel test, you will first be positioned onto a special bed or chair, then a tiny catheter will be passed into the bladder. Another tube with a soft balloon will be placed into the rectum to measure pressures in the abdomen which affect the bladder. Finally, electrode stickers may be placed onto the skin near the anus to record muscle activity of the urinary sphincter. While it may not be pleasant to have these tubes placed, it should not hurt, and any discomfort will be minimised if you are able to remain as relaxed as possible during this time.

    Once the catheters are positioned, they are connected to a computer, which records the pressures in your bladder, and plots out a graph. You may then be repositioned on the chair or table to a seated or lying position, or you may be asked to stand. If you are having a video urodynamic study, an X-ray machine will be positioned in front of your bladder.

    Once you are set up, your bladder will be slowly filled through the catheter with sterile water (for a non-video study) or contrast solution (for a video study). As your bladder fills, the computer will measure pressure changes in your bladder, and you will be asked to report various sensations, like a feeling of fullness, an urge to urinate, and when you cannot hold any more. This part of the test is referred to as the filling cystometrogram.

    If part of your bladder problem involves urine leakage, or incontinence, then during filling, you may be asked to bear down or cough to bring about this leakage. The nurse will try to record the pressure at which leakage occurs. While this may seem a bit unusual or embarrassing, it is important for the study to try to re-produce what happens at home. The goal of this part of the procedure is to determine what is called the leak point pressure, meaning how much pressure it takes to cause a leak.

    Sometimes, at the end of bladder filling, the tube in the bladder will be pulled back to measure pressure in the urethra. This provides a measurement of the strength of the pelvic floor, and the ability of the urethra to close off and prevent leakage of urine. This part of the study is called a urethral pressure profile.

    Once your bladder has been filled, you will be asked to urinate again into a special toilet. This time, the small catheter may be left in the bladder, and you will urinate around it. While unusual, this is actually easier than you might think. Again, X-rays may be taken while you urinate. This part of the exam is called a pressure flow study.

  5. After the test

    Following the procedure, you can resume your normal activities. It is important to drink plenty of fluids afterwards, as this will help to clear any symptoms of burning on urination or blood in the urine.

    Rarely, it may be necessary to call or see your doctor after a urodynamics study, if there is significant bleeding or burning with urination that does not clear quickly, or signs of a serious infection such as fever, chills, or pain in the flanks.

In conclusion

Urodynamics are a safe and well-tolerated procedure. They are an extremely valuable tool to assess bladder function, and they can provide information about your condition which can lead to more effective treatment.