Is a Cystometric Study?
A cystometric study is done to determine the size of your bladder
and how well it functions. Cystometric studies are also called cystometrograms
or CMGs. The procedure measures how much fluid your bladder can hold, how full
it is when you begin to feel the need to urinate, and the pressure of your urinary
Your doctor may want you to have this procedure if you have
trouble completely emptying or controlling your bladder.
Do I Need a Cystometric Study?
Bladder dysfunction can have a significant impact on your quality
of life. Cystometric studies help to measure bladder capacity and function. This
can help your doctor identify specific problems and recommend treatments that
will improve your ability to carry on with normal daily activities.
Bladder problems, including overactive bladder, reduced bladder
capacity, and incomplete emptying, or an inability to empty the bladder
completely, can occur with pregnancy. They can also occur with a variety of
conditions, such as:
- a urinary tract infection (UTI)
- a spinal cord injury
- bacterial prostatitis
- an enlarged prostate, such as from benign
- a neurological disease, such as multiple
- a stroke
Your doctor may prescribe antibiotics before or after the
procedure to help prevent infection. The exact procedure for your cystometric
study will vary slightly based on the doctor, the facility, and your medical
condition. Your doctor will provide you with details specific to your
Happens During a Cystometric Study?
You can have a cystometric study in your doctor’s office, an
outpatient clinic, or a hospital. General anesthesia isn’t necessary. You
shouldn’t have a cystometric study if you have an active UTI because this
procedure may cause your infection to spread to the bladder.
Your doctor may ask you to empty your bladder so that the
technician can record the following measurements:
- how long it takes you to start urinating
- the size and strength of your urine stream
- how long it takes to empty your bladder
- the amount of urine you produce
They will record any difficulties or abnormalities you experience.
The following steps will take place while you’re lying on your
back on a bed or examination table.
- Your doctor will clean the skin around your
urethra and give you local anesthesia.
- Your doctor will then insert a thin tube called
a “catheter” into your
urethra and up into your bladder. This sometimes causes a slight burning
sensation. The catheter will measure how much urine is still in your bladder.
- They will then insert a second catheter into
your rectum, with electrodes placed in the surrounding area. A tube
attached to the catheter called a “cystometer”
measures the pressure.
- Your doctor will fill your bladder with a saline
solution and water. They’ll ask if you feel any of the following:
- an urge to urinate
- You may also feel the sensation of coolness or
warmth from the liquid. It’s possible that your bladder may leak a little
during the procedure. This is normal.
- As your bladder fills, your doctor will ask you
to report when you begin to feel an urge to urinate.
- After your bladder is full, you’ll urinate. Your
doctor will record the pressure of your urine stream.
- They’ll then drain any fluid still in your
bladder and remove the catheters.
The entire procedure will take about 20 to 30 minutes to complete
if there are no complications.
Are the Complications Associated with a Cystometric Study?
During the Procedure
Depending on your medical condition, you may experience some pain
during the procedure. Most people report that inserting the catheter and
filling the bladder causes some discomfort. Other potential side effects
- an urgent need to urinate
For people who have a high spinal cord injury, there’s a risk of
autonomic dysreflexia. This is an abnormal response to the pressure of a full
bladder. Tell your doctor immediately if you begin to have some of these
symptoms during the test:
- feeling flushed
- a headache
- high blood pressure
This is a dangerous condition that can cause a seizure, stroke,
or even death.
After the Procedure
You may have some discomfort during urination for a few days, and
your urine might contain small amounts of blood. Some people also report
getting UTIs. If you have any of the following symptoms, you should contact
your doctor immediately:
- a fever
- excessive bleeding
- increasing pain
These symptoms may indicate that you have an infection.