Fractional Excretion of Sodium
Separates pre-renal from intrinsic acute kidney injury.
When to use it. Working out the cause of oliguric acute kidney injury.
このページの医療安全に関する情報は英語で表示しています。日本語を読む臨床医による確認がまだ済んでおらず、誰も検証していない翻訳に頼るのは安全ではありません。
Fill in every field to see a result.
Limits of this score. FENa is unreliable on diuretics — a loop diuretic forces sodium out and pushes it above 1% whatever the cause; use the fractional excretion of urea instead there. It is also misleading in contrast nephropathy, rhabdomyolysis and glomerulonephritis, all of which can be pre-renal-looking, and in chronic kidney disease.
Sources
- Espinel CH. The FENa test: use in the differential diagnosis of acute renal failure. JAMA 1976;236:579–81.
- Carvounis CP, Nisar S, Guro-Razuman S. Significance of the fractional excretion of urea in the differential diagnosis of acute renal failure. Kidney Int 2002;62:2223–9.
Where this is written from. This site is written from Indian clinical practice. Drug availability and brand names, vaccination schedules, national health programmes and some reference cut-offs differ between countries — a schedule or a threshold that is standard here may not be standard where you are. If you are reading outside India, check anything on this page against your own country’s guidance before you act on it.
Educational use only — not medical advice. Never a substitute for clinical judgement.