Challenge: For each of the following, would you expect these findings in prerenal acute kidney injury or acute tubular necrosis (ATN)?
1. Mannitol administration.
3. Severe burns.
4. A history of vomiting and diarrhea.
5. Muddy brown casts.
6. Bland urinalysis with rare hyaline casts.
7. Improvement of creatinine within 48 hours after IV fluid administration.
8. FENa < 1%
9. BUN/Cr = 12:1.
10. Urine Na+ = 50meq/L.