Urodynamic Testing - Significance and Test Procedures

What Is Urodynamic Testing?

Urodynamic tests are diagnostic tests or procedures that look at how the parts of the lower urinary tract, like the bladder, sphincter, and urethra, work to store and release the urine. These urodynamic tests are used to diagnose patients with urinary incontinence (unable to hold urine) and other lower urinary tract problems. Most of these tests focus on the ability of the bladder to hold and release urine and are used to assess bladder contractions.

Why Is a Urodynamic Test Performed?

Urodynamic testing is done to determine the potential underlying causes for the different kinds of urinary problems. And to get the desired information about the urinary cycles and how well the bladder muscles and nerves and the organs of the lower urinary tract are functioning.

The urodynamic tests are performed if the patient is experiencing the symptoms like:

• Difficulty while urinating.

• Painful urination.

• Frequent urination.

• Bladder emptying problems.

• Repeated urinary tract infections.

• Weak urinary flow.

What Can Be Expected From Urodynamic Testing?

Urodynamic tests can range from recording and assessing measurements, such as daily urine output or the time it takes to clear the bladder, to capture a deeper picture of the urinary bladder. The doctor will examine and make a note of the medical history to determine which urodynamic testing procedure will be most helpful in identifying the problems associated with the urinary tract.

Is Urodynamic Testing Painful?

Usually, the urodynamic tests are not painful and do not need to be performed under general anesthesia. However, the tests using a catheter are done by giving local anesthesia to avoid discomfort or minimal pain.

What Are The Types of Urodynamic Testing?

Depending on the preliminary diagnosis, different urodynamic tests (bladder functioning tests) are available. The physician recommends one or more of these urodynamic tests. The tests are,

• Uroflowmetry: This test measures how much urine is in the bladder and how quickly the urine comes out, known as urine flow rate. The test results confirm if the bladder muscles are weak or the urine flow is blocked. During uroflowmetry tests, an individual needs to urinate in a particular container with two parts: a urine collection container and a scale. Uroflowmetry machines create a graph showing changes in flow rate while urinating. The healthcare professional uses a graph to see when the flow rate is high and how many seconds it takes to get there. This test can measure the flow rate by recording how long it takes to urinate in a specific container that accurately measures how much urine the individual excretes.

• Cystometry: Cystometry is also known as a cystometrogram.This test measures how well the bladder stores urine, the bladder pressure, and how full the bladder is when a person feels the urge to urinate. The cystometric test is performed in sitting, standing, and lying positions. A local anesthetic is given at the insertion site of a catheter to reduce discomfort. In this procedure, two catheters are inserted into the urethra and the other into the rectum. One catheter has a pressure-measuring device, a manometer, and sensors on the abdomen to record the activity of pelvic muscles. Once the bladder is completely empty, it is slowly filled with warm water. The specialist might ask to describe how the bladder feels and when the person feels the need to start urinating. If the individual first feels the urge, the fluid volume and pressure of the bladder are recorded. The specialist also asks to cough or squeeze during this procedure to see if the bladder pressure is changing or if the urine is leaking.

• Electromyography: Electromyography is recommended if the physician suspects that the problem is related to muscle or nerve damage. This test uses special sensors that record the activity of pelvic floor muscles or the muscles of the bladder and sphincter. These sensors are placed near the skin of the urethral or rectal catheter, and a numbing anesthetic gel is applied to reduce the discomfort. The activity of the nerves and muscles is recorded on a machine, and these recorded patterns will show whether there is proper coordination between the nerve impulses and the muscle activity.

• Pressure Flow Study: This test is used to measure the flow rate, the pressure that builds in the bladder, to know about the blockages in the system, and the strength of bladder muscle. This is done after a cystometric test. In this test, the individual is asked to empty his or her bladder while the catheter is still in its place and observe how well the bladder muscles are contracting while urinating. This test is helpful in knowing the blockage of urine in men with prostate enlargement.

• Post-void Residual Measurement: This test measures how much urine is still left in the bladder after urination. It is known as a post-void measurement, which is measured with the help of ultrasound to create a picture of the bladder. In this post-void residual measurement, a score of five to six ounces is considered normal, and more than this score is a sign of incomplete emptying of the bladder.

• Video Urodynamic Tests: These tests use X-rays or ultrasound to capture pictures and videos of the bladder while it gets filled or emptied. The radiologic personnel will fill the bladder with a contrast dye that shows up in the pictures and videos for a better view.

• Leak Point Pressure Management: This test measures the pressure at the leakage point during a cystometric test.

How To Prepare for Urodynamic Testing?

The instructions to prepare for a urodynamic test are :

• Inform the physician about pregnancy, if any, and the test may be postponed.

• For any symptoms like a burning sensation or any signs and symptoms of infection, the test should be postponed until they are treated.

• Take the antibiotics prescribed by the doctor.

• Eat a regular meal on the day of testing and avoid caffeine.

• In case of chronic constipation, the doctor might prescribe an enema a day or a few hours before the procedure.

• Drink enough water before the appointment.

• Inform about all the current medication so that the physician might advise on stopping certain medicines three days before the test.

What To Expect After a Urodynamic Testing?

After a urodynamic test, a person might experience mild discomfort for a few hours. The discomfort usually subsides after a few hours by taking eight ounces of water every half an hour. Taking a warm bath might reduce the discomfort. Some can experience a small amount of blood at the catheter insertion site. The doctor might prescribe antibiotics to prevent infection. In case of any symptoms of infection like fever, chills, or persistent pain, even after an extended period, immediate medical attention is required.

When To Expect About the Test Results?

The results of cystometry and uroflowmetry are available immediately, and for other tests like urodynamic video tests and electromyograms, it will take a few days to get the results.

What Are the Possible Risks and Complications After Undergoing Urodynamic Testing?

The urodynamic tests usually pose no risks. Only a very few can have minimal risk of bladder infection. In very rare cases, autonomic dysreflexia, which is a sudden rise in blood pressure while doing the test, can happen. This needs to be appropriately managed to avoid the severe condition.

Conclusion:

Urodynamic testing is an effective procedure for evaluating the function of the bladder and urethra. In addition, the test is not painful, but the individual might feel slight discomfort after the procedure. These tests are of various types, and the doctor might decide the best procedure based on the preliminary diagnosis.