Approach Considerations
Prostatic massage is performed similarly to a digital rectal examination. The patient is asked to lean forward over the examining table. The physician then puts on gloves and applies lubricant to the examining index finger. Next, the physician spreads the patient’s buttocks and advances the index finger into the anus. The prostate is then massaged by stroking it from the periphery toward the midline several times on each side. EPS is the then collected from the urethra as it exits the penis.
Four-Glass Test
The criterion standard technique of obtaining EPS is known as the Meares-Stamey “4-glass test,” which is difficult and time-consuming. Thus, it is rarely used by urologists.
This 4-glass test begins by asking the patient to provide the 10 mL of urine in one glass. Then, 10 mL of midstream urine is provided in the next glass. Next, prostatic massage is performed, and EPS is collected in a third glass. Finally, postmassage urine is collected in the fourth (final) glass. [9] The initially voided urine is tested for urethral infection, while the midstream urine is tested for bladder infection. The EPS fluid is examined for WBCs. Finally, the postmassage urine is used to flush out bacteria in the prostate that may remain within the urethra. [11]
The resultant samples are labeled VB1 representing the urethra, VB2 representing the bladder, EPS the actual prostatic expressions, and VB3 representing also the prostate.
The 4-glass test is depicted below.
Two-Glass Test
A variation of 4-glass test is known as the Nickel premassage and postmassage test, or the 2-glass test. In this test, the patient is first asked to collect midstream urine into the clean-catch cup, which will be used for premassage culture. The patient is then asked to stop urinating. The physician then massages the prostate from the periphery toward the midline several times. Following the massage, the patient is asked to provide more urine for postmassage urine cultures.
A study by the department of urology at Kingston General Hospital in Ontario, Canada, sought to determine if the 2-glass test was a useful alternative to the more cumbersome 4-glass test, evaluating whether the 2-glass test can offer the accuracy of 4-glass test without the EPS fluid obtained with the latter. The study involved 353 men enrolled in the NIH Chronic Prostatitis Cohort study, all of whom had confirmed baseline leukocyte counts and 2-day bacterial cultures that were obtained using the 4-glass test.
The study showed that the 2-glass test yielded results in concordance with those of the 4-glass test and was used to predict the correct diagnosis in 96% of cases. They concluded that the 2-glass test is ultimately an acceptable alternative to the 4-glass test despite no prostatic fluid being obtained. [12]
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The 4 glass test.
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Classification of prostatitis
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NIH Chronic prostatitis symptom index (NIH-CPSI)
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Classification of prostatitis
