What is a common sign of acute kidney injury that may prompt evaluation in urology patients?

• A. Decreased urine output with normal creatinine
• B. Elevated serum creatinine with increased glomerular filtration rate
• C. Normal creatinine with diuresis
• D. Elevated serum creatinine and reduced urine output

Answer: (D)

Acute kidney injury shows up when the kidneys suddenly fail to filter waste and produce urine properly. The most telling signal is when the urine output drops and the blood test shows rising creatinine, indicating a fall in filtration rate. This combination— elevated serum creatinine with reduced urine output—is a classic pattern that prompts evaluation in urology patients because it points to an acute problem affecting kidney function, such as obstruction, nephrotoxic injury, or other acute processes needing attention.

Why the other patterns aren’t as consistent: a rise in creatinine with an increased GFR isn’t plausible—GFR goes down in kidney injury. Normal creatinine with diuresis suggests adequate or excess urine production, not AKI. Decreased urine output with normal creatinine can occur early or in other conditions, but the simultaneous rise in creatinine and oliguria best reflects the abrupt decline in kidney function that AKI represents.