How would the urine of a person suffering from acute kidney failure be different from a healthy person?

Cells,casts: Urinalyis in acute renal failure helps to determine the cause, rbcs and RBC casts indicate a glomerulonephritis, wbcs an infection and WBC casts pyelonephritis. Muddy brown casts indicate atn. These findings are absent in health. The fractional excretion of sodium in typically higher in acute tubular necrosis vs prerenal states. The presence of protein and bile etc can help diagnose the problem.