A female adult client with a gunshot wound to the abdomen shows an assessment finding consistent with acute renal failure. Which finding supports ARF?

• A. BUN 22 mg/dl
• B. Serum creatinine 1.2 mg/dl
• C. Temperature 100.2° F (37.8° C)
• D. Urine output 400 ml/24 hours

Answer: (D)

Acute renal failure shows a rapid drop in kidney function with markedly reduced urine production, or oliguria. A urine output of about 400 mL in 24 hours is a clear, objective sign of oliguria in an adult and fits the pattern of ARF due to the kidneys’ impaired ability to form urine. BUN and creatinine values can be normal or only mildly elevated early on and depend on hydration and other factors, so they’re not as definitive on their own. A fever is nonspecific and not diagnostic of ARF. In short, the notably low urine output is the finding that most strongly supports ARF in this scenario.