INCONTINENCE and URODYNAMIC TESTING
How does the bladder work?
Several muscles, organs, and nerves are involved in collecting, storing, and releasing urine. The kidneys form urine by filtering wastes and extra water from the bloodstream. The ureters are tubes that carry urine from the kidneys to the bladder. Normal urine flow is one way. If urine backs up toward the kidneys, infections are more likely.
The bladder, a hollow muscular organ shaped like a balloon, sits in the pelvis and is held in place by ligaments attached to other organs and to the pelvic bones. The bladder stores urine until you are ready to empty it. It swells into a round shape when it is full and gets smaller as it empties. A healthy bladder can hold up to 16 ounces (2 cups) of urine comfortably for 2 to 5 hours.
The bladder opens into the urethra, the tube that allows urine to pass outside the body. Circular muscles called sphincters close tightly to keep urine from leaking.
Nerves in the bladder tell you when it is time to empty your bladder. When the bladder begins to fill with urine, you may notice a feeling that you need to urinate. The sensation becomes stronger as the bladder continues to fill and reaches its limit. At that point, nerves in the bladder send a message to the brain, and your urge to urinate intensifies.
When you are ready to urinate, the brain signals the sphincter muscles to relax. At the same time, the brain signals the bladder muscles to tighten, squeezing urine out. Urine can then leave the bladder through the urethra. When these signals occur in the correct order, normal urination occurs.
What is incontinence?
The involuntary leakage of urine is called incontinence.
What causes incontinence?
Problems in the urinary system can be caused by aging, illness, or injury. The muscles in your ureters, bladder, and urethra tend to become weaker with age. You may have more urinary infections because your bladder muscles have weakened and cannot empty your bladder completely. Also, weakening in the muscles of the sphincters and the pelvis can cause incontinence because the sphincter cannot remain tight enough to hold urine in the bladder or does not have enough support from the pelvic muscles.
What should I do first?
The first step in solving a urinary problem is to talk to your doctor or nurse. He or she will ask you about your general medical history, including any major illnesses or surgeries. You should talk about the medicines you take, both prescription and nonprescription, because they might be part of the problem. You should talk about how much fluid you drink a day and whether you use alcohol or caffeine. Give as many details as you can about the problem and when it started.
Dr. Taylor will perform a physical exam to rule out other causes of urinary problems, such as weakening pelvic muscles.
How are the causes of incontinence diagnosed?
Urodynamics is the study of how the body stores and releases urine. Urodynamic tests help your doctor or nurse see how well your bladder and sphincter muscles work and can help explain symptoms such as
- incontinence
- frequent urination
- sudden, strong urges to urinate
- problems starting a urine stream
- painful urination
- problems emptying your bladder completely
- recurrent urinary tract infections
Most urodynamic testing focuses on the bladder's ability to empty steadily and completely. It can also show whether the bladder is having abnormal contractions that cause leakage. Dr. Taylor will want to know whether you have difficulty starting a urine stream, how hard you have to strain to maintain it, whether the stream is interrupted, and whether any urine is left in your bladder when you are done (postvoid residual).
Urodynamic tests can range from simple observation to precise measurement using sophisticated instruments.
What types of urodynamic tests will the doctor use?
Any procedure designed to provide information about a bladder problem can be called a urodynamic test. The type of test you take depends on your problem.
UROFLOWMETRY
A uroflowmeter automatically measures the amount of urine and the flow rate (how fast the urine comes out). You may be asked to urinate privately into a toilet that contains a collection device and scale. This equipment creates a graph that shows changes in flow rate from second to second so the doctor or nurse can see the peak flow rate and how many seconds it took to get there. Results of this test will be abnormal if the bladder muscle is weak or urine flow is obstructed.
Your doctor or nurse can also get some idea of your bladder function by using a stopwatch to time you as you urinate into a graduated container.
MEASUREMENT OF POSTVOID RESIDUAL
After you have finished, you may still have some urine, usually only an ounce or two, remaining in your bladder. To measure this postvoid residual, the doctor or nurse may remove it with a catheter, a thin tube that can be gently glided into the urethra. Ultrasound equipment that uses harmless sound waves to create a picture of the bladder can also be used.
MEASUREMENT OF LEAK POINT PRESSURE
While your bladder is being filled for the CMG, it may suddenly contract and squeeze some water out without warning. The cystometer will record the pressure at the point when the leakage occurred. This reading may provide information about the kind of bladder problem you have.
You may also be asked to try to exhale while holding your nose and mouth to apply abdominal pressure to the bladder or cough or shift positions. These actions help the doctor or nurse evaluate your sphincter muscles.
PRESSURE FLOW STUDY
After the CMG, you will be asked to empty your bladder so that the catheter can measure the pressures required to urinate. Bladder outlet obstruction can occur with a fallen bladder or rarely after a surgical procedure for urinary incontinence.
When will I know the results?
Results for simple tests can be discussed with your doctor or nurse immediately after the test. Results of other tests may take a few days. You will have the chance to ask questions about the results and possible treatments for your problem.
What happens after the testing?
You may have mild discomfort for a few hours after these tests. Drinking two 8-ounce glasses of water each hour for 2 hours should help. Ask your doctor whether you can take a warm bath. If not, you may be able to hold a warm, damp washcloth over the urethral opening to relieve the discomfort.
Your doctor may give you an antibiotic to take for 1 or 2 days to prevent an infection. If you have signs of infection—including pain, chills, or fever—call your doctor at once.
Will I need surgery?
After reviewing the results of your examination and testing, Dr. Taylor may recommend “suspension” surgery, called retropubic urethropexy. This procedure stabilizes the urethra from tilting by using stitches to attach it to muscle tissue in the pelvic area.
Source:
This material has been adapted from information made available by the United States National Institute of Diabetes & Digestive & Kidney Diseases, of the National Institutes of Health: