A 58-year-old male client is admitted to the ICU following emergency abdominal surgery. Over the past 6 hours, his urine output has dropped to 15 mL/hour, serum creatinine has risen from 0.9 mg/dL to 2.4 mg/dL, and his BUN is 38 mg/dL. His blood pressure is 88/54 mmHg and he received 2 L of IV normal saline intraoperatively. The primary health care provider suspects prerenal acute kidney injury. Which assessment finding would best support a prerenal rather than intrinsic renal cause of this client's acute kidney injury?
- Presence of muddy brown granular casts on urinalysis
- Serum potassium of 5.8 mEq/L with peaked T-waves on ECG
- Urine specific gravity of 1.010 with urine sodium of 45 mEq/L
- Urine sodium of 8 mEq/L with a fractional excretion of sodium (FeNa) less than 1%