In a patient who complains of urinary incontinence, a cystometrogram is performed to
**Core Concept**
A cystometrogram is a diagnostic test used to assess the function of the bladder and the urethra. It measures the pressure within the bladder as it fills with fluid and the patient experiences the sensation of a full bladder. This test helps in diagnosing conditions such as overactive bladder, stress incontinence, and detrusor overactivity.
**Why the Correct Answer is Right**
The correct answer is to assess the bladder sensation and capacity. During a cystometrogram, the patient is asked to report when they feel the sensation of a full bladder. This is crucial in determining the bladder's ability to store urine and the patient's perception of bladder fullness. The test also measures the detrusor pressure, which is the pressure exerted by the bladder muscle as it contracts. This information is essential in diagnosing conditions such as detrusor overactivity, where the bladder muscle contracts too frequently.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a cystometrogram is not primarily used to assess the urethral sphincter's function. While the urethral sphincter plays a role in urinary continence, a cystometrogram focuses on the bladder and its function.
**Option B:** This option is incorrect because a cystometrogram does not involve the insertion of a catheter into the urethra for the purpose of measuring urine flow. While urine flowmetry is a related test, a cystometrogram is focused on bladder pressure and sensation.
**Option C:** This option is incorrect because a cystometrogram is not used to assess the bladder's ability to contract. While the detrusor muscle does contract during a cystometrogram, the test is focused on measuring bladder sensation and capacity, not bladder contractility.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that a cystometrogram is a useful diagnostic tool for patients with urinary incontinence, but it should be interpreted in conjunction with other tests, such as urodynamic studies and imaging studies, to get a comprehensive understanding of the patient's urinary tract function.
**Correct Answer:**
A. assess the bladder sensation and capacity.