Fractional filtered sodium excretion FENa

The filtered sodium excretion fraction, also known as FENa, is the percentage of sodium that is measured by glomerular filtration of sodium and urinary excretion, that is, the percentage of sodium that is glomerularly filtered and not reabsorbed by the renal tubules. Calculation formula sodium excretion fraction = [(urine sodium × serum creatinine) / (blood sodium × urine creatinine)] × 100%; sodium excretion fraction is the most sensitive indicator for distinguishing prerenal acute renal failure and acute tubular necrosis, positive rate 98%. Prerenal acute renal failure due to the reabsorption of sodium by the renal tubules is relatively high, so that the discharge of urinary sodium is reduced, and FENa is significantly reduced. Acute tubular necrosis, renal tubules can not absorb Na, so the urine Na discharge is significantly increased. The use of diuretics can increase the discharge of urinary sodium, so at this time can not rely on sodium excretion score as a basis for diagnosis. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Tips: Keep regular routines and diet. Normal value Under normal circumstances, FENa (%) < 1. An elongated epithelial tubule connected to the renal tubule wall layer for reabsorption and excretion. The main physiological function of the renal tubule is to absorb water, electrolytes and nutrients (such as glucose, amino acids, etc.) in the raw urine, followed by secretion (H+, K+ and organic substances), excretion waste (urea and organic acids, etc.). Concentration and dilution of urine are also important physiological functions of the renal tubules. Clinical significance Abnormal results: FENa (%) is a sensitive indicator for the identification of pre-renal azotemia and acute tubular necrosis, pre-renal azotemia FENa (%) <1, acute tubular necrosis FENa (%)> 2 . Between 1 and 2 is a blank area, the former reabsorbs sodium to strengthen, so that FENa (%) even drops to O.1, the latter often exceeds 3. People to be examined: pre-renal azotemia and acute tubular necrosis. Precautions Taboo before the examination: Maintain regular routines and diet to help the inspection proceed smoothly. Requirements for examination: The patient takes the urine according to the doctor's examination, the doctor carefully checks and carefully observes the result. Inspection process Allow the patient to drink 10-20 ml/kg before the test. To maintain proper urine output. The doctor took the urine for examination, and calculated the results according to the formula: sodium excretion score = [(urine sodium × serum creatinine) / (blood sodium × urine creatinine)] × 100%, the results are compared with normal values, to determine the symptoms. Not suitable for the crowd Inappropriate people: Generally, there is no suitable for the crowd. Adverse reactions and risks No related complications or hazards.

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