Cystometry is a diagnostic test that assesses the function of the bladder and urethra, focusing on how well the bladder fills and empties. This procedure helps healthcare providers understand the bladder’s mechanics, including its muscle function, nerve responses, and overall capacity. It is used to investigate various urinary control problems.
What is Cystometry and Why It’s Performed
Cystometry measures the bladder’s capacity, the pressure within it, and how it responds to different sensations. The bladder is a muscular organ that relaxes to store urine and contracts to release it, with nerves sending signals to the brain to coordinate this process. When these nerve pathways or muscles are not functioning properly, it can lead to issues with bladder control or emptying.
Doctors recommend cystometry to investigate symptoms like frequent urination, urinary incontinence (involuntary leakage of urine), difficulty emptying the bladder, or a weak urine stream. Conditions such as neurogenic bladder dysfunction (bladder problems due to nervous system issues), diabetes, or prostate enlargement can interfere with bladder function and lead to these symptoms. The test helps identify the underlying cause of such urinary problems.
The Cystometry Procedure
Preparation for a cystometry test involves emptying the bladder as completely as possible. You may be asked to urinate into a special toilet connected to a uroflowmeter, which measures urine flow rate and volume. Afterward, you will lie on an examination table, and the area around your urethra will be cleaned.
A thin, flexible tube called a catheter is then inserted through the urethra into the bladder. This catheter measures any urine remaining in the bladder, known as post-void residual volume, and connects to a cystometer to measure bladder pressure. Another small catheter or pressure probe might be placed in the rectum or vagina to measure abdominal pressure, and electrodes may be placed on the skin near the anal opening to assess muscle function.
The bladder is then slowly filled with a sterile fluid, such as water or saline, through the catheter. During this filling, you will be asked to describe sensations such as warmth, the first urge to urinate, and when your bladder feels completely full. Bladder pressure is continuously recorded, and you may be asked to cough or strain to observe bladder responses. Once the bladder is full, you will be asked to empty it into a commode while pressure and flow rates are still being recorded.
Understanding Your Cystometry Results
Cystometry provides measurements that help your doctor understand bladder function. These include bladder capacity, indicating how much urine your bladder can hold before a strong urge to urinate. The test also measures bladder pressure at rest, during filling, and during voiding, which can reveal issues like an overactive detrusor muscle or bladder outlet obstruction.
The results also provide insight into bladder sensitivity, indicating if you feel the urge to urinate too early or too strongly. The test assesses how completely the bladder empties, identifying any residual urine volume that might remain after urination. Analyzing these measurements helps healthcare providers determine if problems are related to muscle function, nerve signals, or structural issues, guiding treatment.
After Your Cystometry Test
After the cystometry test, the catheters and any external electrodes are removed. You may experience some mild side effects such as burning during urination, an increased frequency or urgency to urinate, or a slight pink or reddish tint to your urine. These symptoms subside within a day or so.
To help alleviate discomfort and flush your bladder, it is recommended to drink plenty of fluids after the procedure. Avoiding caffeinated, carbonated, or alcoholic beverages is also advised as they can irritate the bladder lining. Contact your healthcare provider if you experience persistent pain, fever, chills, a significant reduction in urine output, or increased blood in your urine, as these could be signs of an infection.