In men with bladder outlet obstruction, what does an elevated post-void residual (PVR) after voiding most likely indicate?

In men with bladder outlet obstruction, what does an elevated post-void residual (PVR) after voiding most likely indicate?

• A. Normal bladder function
• B. Obstruction or poor detrusor contractility
• C. Overhydration
• D. Urinary tract infection

Answer: (B)

An elevated post-void residual means the bladder isn’t emptying completely after urination. In men with bladder outlet obstruction, the blockage makes it hard to push urine out, so more urine remains in the bladder. Over time, the detrusor muscle can become weak from the increased effort, leading to poor detrusor contractility and still more urine left behind. This combination—ongoing obstruction and potential detrusor underactivity—is the most likely explanation for a high residual. Normal bladder function would leave little urine behind after voiding, overhydration doesn’t inherently create a persistent residual, and a urinary tract infection doesn’t typically cause elevated PVR by itself.

An elevated post-void residual means the bladder isn’t emptying completely after urination. In men with bladder outlet obstruction, the blockage makes it hard to push urine out, so more urine remains in the bladder. Over time, the detrusor muscle can become weak from the increased effort, leading to poor detrusor contractility and still more urine left behind. This combination—ongoing obstruction and potential detrusor underactivity—is the most likely explanation for a high residual. Normal bladder function would leave little urine behind after voiding, overhydration doesn’t inherently create a persistent residual, and a urinary tract infection doesn’t typically cause elevated PVR by itself.