FENA =
((Urine_Sodium/Plasma_Sodium)*100
---------------------------------------
(Urine_Creatinine/Plasma_Creatinine))
(3)
FeNa < 1 % - prerenal failure: dehydration more than chf, acute glomerulonephritis
FeNa > 2 % - intrinsic disease: acute tubular necrosis, vasculitis, interstitial
nephritis (1,2)
Sources:
1. Le, Tao, Vikas Bhushan, Robert W. Grow, and Veronique Tache.First Aid for
the USMLE Step 3. 2nd ed. New York: McGraw Hill, 2008. Print.
2. Current Medical Diagnosist and Treatment 2005