Post-cardiac surgery assessment of renal function should be performed hourly for the first 12 to 24 hours. Identify the laboratory result that the nurse knows is a primary indicator of possible renal failure.

Post-cardiac surgery assessment of renal function should be performed hourly for the first 12 to 24 hours. Identify the laboratory result that the nurse knows is a primary indicator of possible renal failure.

Post-cardiac surgery assessment of renal function should be performed hourly for the first 12 to 24 hours. Identify the laboratory result that the nurse knows is a primary indicator of possible renal failure.


a) An hourly urine output of 50 to 70 mL

b) A urine specific gravity reading of 1.021

c) A serum BUN of 70 mg/dL

d) A serum creatinine of 1.0 mg/dL



Answer: A serum BUN of 70 mg/dL