FeNa Calculator

Calculates the fractional excretion of sodium based on urine sodium, plasma sodium, urine creatinine, and serum creatinine. Determines the cause of acute renal failure.

FeNa Calculator

 

FeNa < 1 % - prerenal failure: dehydration more than chf

FeNa > 2 % - intrinsic disease: acute tubular necrosis, vasculitis, interstitial nephritis

 

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. Up to Date
http://www.utdol.com/online/content/topic.do?topicKey=renlfail/11711&selectedTitle=1~32&source=search_result#