Calculations must be re-checked, shouldn't be used alone for patient care, and don't substitute for professional judgment. See our full disclaimer.
Determines if renal failure is due to pre-renal, post-renal, or intrinsic renal pathology.
Fractional Excretion of Sodium (FENa) = (PCr * UNa ) / (PNa x UCr) %
Prerenal: Anything that causes decreased effective renal perfusion: Hypovolemia, CHF, Renal Artery Stenosis, Sepsis, etc. Remember, contrast-induced nephropathy will often look pre-renal.
Intrinsic Renal: ATN, AIN, Glomerulonephritides, etc
Postrenal: Obstruction (BPH, bladder stone, bilateral ureter obstruction)
Calculations must be re-checked and should not be used alone to guide patient care nor should they substitute for clinical judgement. disclaimer