A client is monitored for potential renal failure after a severe trauma. Which assessment finding would warrant immediate reporting?

• A. Creatinine 1.1 mg/dL (normal)
• B. Urinary output of 150 mL per hour
• C. Gradual increase of BUN levels
• D. Calcium 9.0 mg/dL (normal)

Answer: (C)

Rising BUN indicates the kidneys aren’t filtering waste effectively, which is a key sign of acute kidney injury or declining renal perfusion after trauma. BUN tends to rise earlier than creatinine in acute changes to kidney function, so a gradual increase in BUN is a timely red flag that needs immediate assessment and intervention.

The other findings are less concerning in this context: creatinine being normal can occur early in kidney injury, but it doesn’t rule out evolving impairment; urine output of 150 mL/hour shows adequate urine production, suggesting perfusion is still sufficient at the moment; and a normal calcium level doesn’t point to an acute renal issue by itself.