U_Na=20,S_Cr=1.5,S_Na=140,U_Cr=120 → FENa = 0.1786%(肾前性) FENa = (20×1.5)/(140×120)×100 = 0.1786%。低于 1%,符合肾前性氮质血症(钠潴留状态)。{"result":"FENa = 0.1786% (< 1% — Consistent with prerenal azotemia). Method: FENa = (U_Na·S_Cr)/(S_Na·U_Cr)·100.","metadata":{"input":{"urineSodium":20,"serumCreatinine":1.5,"serumSodium":140,"urineCreatinine":120},"result":{"fena":0.1786,"unit":"%","category":"< 1%","interpretation":"Consistent with prerenal azotemia (sodium-avid state). Consider volume depletion, heart failure, hepatorenal syndrome. Caution: contrast/sepsis ATN and diuretics can also yield low FENa.","method":"FENa = (U_Na·S_Cr)/(S_Na·U_Cr)·100","model":"Espinel CH. JAMA 1976;236(6):579-581. Most useful in oliguric AKI. Not medical advice."}}}
U_Na=60,S_Cr=2.0,S_Na=135,U_Cr=60 → FENa = 1.4815%(肾性/ATN) FENa = (60×2.0)/(135×60)×100 = 1.4815%。≥1%,符合肾性损伤(典型为急性肾小管坏死 ATN)。{"result":"FENa = 1.4815% (1–4% — Consistent with intrinsic renal injury, typically ATN). Method: FENa = (U_Na·S_Cr)/(S_Na·U_Cr)·100.","metadata":{"input":{"urineSodium":60,"serumCreatinine":2,"serumSodium":135,"urineCreatinine":60},"result":{"fena":1.4815,"unit":"%","category":"1–4%","interpretation":"Consistent with intrinsic renal injury, typically acute tubular necrosis (ATN). Damaged tubules cannot reabsorb sodium effectively.","method":"FENa = (U_Na·S_Cr)/(S_Na·U_Cr)·100","model":"Espinel CH. JAMA 1976;236(6):579-581. Most useful in oliguric AKI. Not medical advice."}}}